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Impact of declining Arctic sea ice on winter snowfall
While the Arctic region has been warming strongly in recent decades, anomalously large snowfall in recent winters has affected large parts of North America, Europe, and east Asia. Here we demonstrate that the decrease in autumn Arctic sea ice area is linked to changes in the winter Northern Hemisphere atmospheric circulation that have some resemblance to the negative phase of the winter Arctic oscillation. However, the atmospheric circulation change linked to the reduction of sea ice shows much broader meridional meanders in midlatitudes and clearly different interannual variability than the classical Arctic oscillation. This circulation change results in more frequent episodes of blocking patterns that lead to increased cold surges over large parts of northern continents. Moreover, the increase in atmospheric water vapor content in the Arctic region during late autumn and winter driven locally by the reduction of sea ice provides enhanced moisture sources, supporting increased heavy snowfall in Europe during early winter and the northeastern and midwestern United States during winter. We conclude that the recent decline of Arctic sea ice has played a critical role in recent cold and snowy winters.
Liu, Jiping; Curry, Judith A.; Wang, Huijun; Song, Mirong; Horton, Radley M.
Impact of increasing temperature on snowfall in Switzerland
NASA Astrophysics Data System (ADS)
The exact impact of changing temperatures on snow amounts is extremely important for mountainous regions, not only for hydrological aspects but also for winter tourism and the leisure industry in winter ski resorts. However, the impact of increasing temperatures on snowfall amounts is difficult to measure because of the large natural variability of precipitation. In addition, the impact of increasing temperatures varies, depending on region and altitude. Moreover, the impact of the observed increasing trend in temperature on snowfall and snow cover has usually been investigated on a seasonal basis only. On a monthly basis, the relationship between this increase in temperature and snowfall is still largely unknown. Of particular concern are the autumn and spring months and variations with altitude. In order to isolate the impact of changing temperatures on snowfall from the impact of changes in the frequency and intensity of total precipitation, we analyzed the proportion of snowfall days compared to precipitation days for each month from November to April in Switzerland. Our analyses concern 52 meteorological stations located between 200 and 2700 m asl over a 48 year time span. Our results show clear decreasing trends in snowfall days relative to precipitation days for all months (November to April) during the study period 1961-2008. Moreover, the present conditions in December, January and February correspond to those measured in the 1960's in November and March. During the whole snow season, the snowfall ratios have been transferred in elevation by at least 300 m from 1961 to 2008. This means that with an expected temperature increase during the coming decades at least similar to the temperature rise of recent decades, we can assume an additional similar altitudinal transfer of the snowfall days relative to precipitation days ratios. The current situation in November and March could thus become the future situation in December, January and February. During the coming decades, the December, January and February snowfall days relative to precipitation days ratios for the altitude class 1101-1400 m asl would gradually shrink to only approximately 50%. For ski resorts with a base below 1400 m asl, December, January and February will be problematic, because at least one out of two precipitation days will consist of rainfall only. The beginning and end of the ski seasons (November, March-April) will also be affected by the transfer in altitude of snowfall, as currently already approximately every second precipitation day consists of rain up to 1400 m asl in November and March and up to 1700 m asl in April.
Serquet, G.; Marty, C.; Rebetez, M.
Dust Activity during Winter Time in East Asia and Snowfall Obervations and Simulations in Taiwan
NASA Astrophysics Data System (ADS)
Taiwan has relatively frequent snowfall in mountain during winter among regions of the same latitude. The phenomenon is contributed by Taiwan's unique topography - high and steep mountains, and geographical location - sitting on the route the continental polar air mass travels from its birthplace to the ocean, contribute to this phenomenon. Snow occurence, in addition to the freezing-point temperature, when two requirements are met: sufficient vapor and the condensation nuclei in the air. This study pursues the causes of the snowfall activity in Taiwan, the relations between the East Asian dust aerosol and the snowfall activity in Taiwan, and the impacts the climate changes have on the snowfall activity in Taiwan. In this study, Yushan snowfall activity from 1995~2011 and related atmosphere circulations were examined using SYNOP data, NCEP/DOE reanalysis atmospheric data, the observations of the Central Weather Bureau's Yushan Weather Station and the Taiwan Air Quality Monitoring Network of the Environment Protect Administration, Executive Yuan. To provide a quantitative measure of snowfall events and dust activity, a snowfall activity index (SAI) and the DAI Index by Yu et al. (2010) were defined. The time series of yearly SAI and DAI show that East Asian dust storm activity and Taiwan snowfall marked interannual variations during 1995 ~ 2011. For active years such as 2008, 2010, and 2011, SAI was hundreds of times larger than that for inactive years such as 1996, 1999 and 2003; and DAI in active years such as 2001 and 2002 was several tens of times larger than that in inactive years such as 1997 and 2003. In active years when the EAT (East Asian Trough) was shifted eastward, the strength of WPH (West Pacific High) increased in the south and an anticyclone thus occurred. This anticyclone introduced anomalous southwesterly flows along the southeastern coast of mainland China and over Taiwan, resulting in a wetter-than-normal atmosphere in support of snowfall. Oppositely, for inactive years, drier-than-normal atmosphere appeared and consequently sluggish snowfall seasons followed. A SVD (singular value decomposition) analysis of the Asian synoptic circulation indicated that the connection between the pressure dipoles and the position of EAT is strong in 1998, 1999, 2001, 2002, 2003, 2010, and 2011. It significantly affects both of the snowfall and dust activities. In summary, snowfall active years usually occurred when the East Asian dust storm was inactive. Nevertheless, the snowfall activity increased in Taiwan if there was dust event and the dust aerosol successfully transported to Taiwan. This finding is also demonstrated in the model simulation of this study.
Tsai, L.
High correlation between winter precipitation and air temperature in heavy-snowfall areas in Japan
Long-term data of winter air temperature and precipitation were analyzed and the correlation between them investigated in order to identify the factors influencing snow reduction during the recent warmer winters in the heavy-snowfall areas in Japan. A high negative correlation between winter precipitation and air temperature was identified in the heavy-snowfall areas on the Sea of Japan side in the
Yukari Takeuchi; Yasoichi Endo; Shigeki Murakami
Regional Snowfall Distributions Associated with ENSO: Implications for Seasonal Forecasting.
NASA Astrophysics Data System (ADS)
Regional changes in early, middle, and late winter total snowfall distributions are identified over the continental United States in association with warm and cold phases of the El Ni�o-Southern Oscillation (ENSO). The analysis is primarily motivated by a desire to improve winter season climate forecasts. Original interest in snowfall associated with ENSO was provided by requests for skiing forecasts during the 1997 ENSO warm phase. Geographic regions with internally similar ENSO warm, cold, and neutral phase snowfall distributions are identified using a composite technique. The composites reveal three early winter, five midwinter, and three late winter regions with shifts in the upper-, middle, and lower-quartile seasonal snowfall. The quartile shifts revealed by the composite technique are important for forecasting applications; however, snowfall impact studies rely more on the absolute magnitude of the change in snowfall at individual stations. Potential impacts of the shifts in snowfall distributions associated with ENSO are discussed using the quartile snowfall magnitudes for the stations in the composites. Shifts in regional snowfall distributions are compared to published ENSO winter climate studies, and hypotheses are presented to relate physical processes to the warm, cold, and neutral phase snowfall distributions.Principal findings include increased snowfall during an ENSO cold phase relative to warm and neutral phases in the northwestern states from early through midwinter, less (more) snowfall during a cold (warm) phase relative to neutral years in the Northeast, and less snowfall (relative to neutral winters) in both warm and cold phases in the Ohio Valley (early winter) and Midwest (midwinter). Combining these snowfall regions with an ever-improving ability to forecast ENSO warm and cold phases will improve seasonal snowfall forecasts. The results should improve mitigation strategies for agencies adversely impacted by ENSO-induced snowfall anomalies.
Smith, Shawn R.; O'Brien, James J.
Spatial and Temporal Trends of Snowfall in Central New York - A Lake Effect Dominated Region
NASA Astrophysics Data System (ADS)
Central New York is located in one of the snowiest regions in the United States, with the city of Syracuse, New York the snowiest metropolis in the nation. Snowfall in the region generally begins in mid-November and lasts until late-March. Snow accumulation occurs from a multitude of conditions: frontal systems, mid-latitude cyclones, Nor'easters, and most notably lake-effect storms. Lake effect snowfall (LES) is a difficult parameter to forecast due to the isolated and highly variable nature of the storm. Consequently, studies have attempted to determine changes in snowfall for lake-effect dominated regions. Annual snowfall patterns are of particular concern as seasonal snowfall totals are vital for water resources, winter businesses, agriculture, government and state agencies, and much more. Through the use of snowfall, temperature, precipitation, and location data from the National Weather Service's Cooperative Observer Program (COOP), spatial and temporal changes in snowfall for Central New York were determined. In order to determine climatic changes in snowfall, statistical analyses were performed (i.e. least squares estimation, correlations, principal component analyses, etc.) and spatial maps analyzed. Once snowfall trends were determined, factors influencing the trends were examined. Long-term snowfall trends for CNY were positive for original stations (�0.46 +/- 0.20 in. yr -1) and homogenously filtered stations (0.23 +/- 0.20 in. yr -1). However, snowfall trends for shorter time-increments within the long-term period were not consistent, as positive, negative, and neutral trends were calculated. Regional differences in snowfall trends were observed for CNY as typical lake-effect areas (northern counties, the Tug Hill Plateau and the Southern Hills) experienced larger snowfall trends than areas less dominated by LES. Typical lake-effect months (December - February) experienced the greatest snowfall trend in CNY compared to other winter months. The influence of teleconnections on seasonal snowfall in CNY was not pronounced; however, there was a slight significant (5%) correlation (< 0.35) with the Atlantic Multidecadal Oscillation. It was not clear if changes in air temperature or changes in precipitation were the cause of variations in snowfall trends. It was also inconclusive if the elevation or distance from Lake Ontario resulted in increased snowfall trends. Results from this study will aid in seasonal snowfall forecasts in CNY, which can be used to predict future snowfall. Even though the study area is regionally specific, the methods may be applied to other lake effect dominated areas to determine temporal and spatial variations in snowfall. This study will enhance climatologists and operational forecasters' awareness and understanding of snowfall, especially lake effect snowfall in CNY.
Hartnett, Justin Joseph
Role of extreme snowfall events in interannual variability of snowfall accumulation in the western United States
NASA Astrophysics Data System (ADS)
resources in the western United States are contingent on interannual variations in snowpack. Interannual snowpack variability has been attributed to large-scale climate patterns including the El Ni�o-Southern Oscillation (ENSO), however, the contribution of snowfall frequency and extreme snowfall events to this variability are less well quantified. Long-term records from Snowpack Telemetry and Cooperative Observer Program stations in the 11 western states were used to investigate these relationships by considering the number of snowfall days and snowfall water equivalent (SFE) of extreme snowfall events. The top decile of snowfall events contributed 20-38% of annual SFE, depending on the region. An average of 65% and 69% of the interannual variability in annual SFE was explained by snowfall days and SFE of top decile snowfall events, respectively, with extreme events being a more significant predictor at most stations. The latitudinal dipole in SFE during ENSO phases results from changes in snowfall frequency and extreme events. In the Pacific Northwest, above normal SFE during La Ni�a winters was a product of both larger contributions from extremes and more snowfall days, while below normal SFE during El Ni�o winters was primarily associated with a substantial reduction in extremes. Conversely, annual SFE during ENSO phases in the mountains of Arizona was more closely linked to fluctuations in snowfall days than extremes. Results indicate the importance of extreme snowfall events in shaping interannual variability in water resources and suggest that improved predictive ability may inform better water resource management now and in the coming decades.
Lute, A. C.; Abatzoglou, J. T.
Variations in northern hemisphere snowfall: An analysis of historical trends and the projected response to anthropogenic forcing in the twenty-first century
NASA Astrophysics Data System (ADS)
Snowfall is an important feature of the Earth's climate system that has the ability to influence both the natural world and human activity. This dissertation examines past and future changes in snowfall related to increasing concentrations of anthropogenic greenhouse gases. Snowfall observations for North America, derived snowfall products for the Northern Hemisphere, and simulations performed with 13 coupled atmosphere-ocean global climate models are analyzed. The analysis of the spatial pattern of simulated annual trends on a grid point basis from 1951 to 1999 indicates that a transition zone exists above 60� N latitude across the Northern Hemisphere that separates negative trends in annual snowfall in the mid-latitudes and positive trends at higher latitudes. Regional analysis of observed annual snowfall indicates that statistically significant trends are found in western North America, Japan, and southern Russia. A majority of the observed historical trends in annual snowfall elsewhere in the Northern Hemisphere, however, are not statistically significant and this result is consistent with model simulations. Projections of future snowfall indicate the presence of a similar transition zone between negative and positive snowfall trends that corresponds with the area between the -10 to -15�C isotherms of the multi-model mean temperature of the late twentieth century in each of the fall, winter, and spring seasons. Redistributions of snowfall throughout the entire snow season are likely -- even in locations where there is little change in annual snowfall. Changes in the fraction of precipitation falling as snow contribute to decreases in snowfall across most Northern Hemisphere regions, while changes in precipitation typically contribute to increases in snowfall. Snowfall events less than or equal to 5 cm are found to decrease in the future across most of the Northern Hemisphere, while snowfall events greater than or equal to 20 cm increase in some locations, such as northern Quebec. A signal-to-noise analysis reveals that the projected changes in snowfall are likely to become apparent during the twenty-first century for most locations in the Northern Hemisphere.
Krasting, John P.
Atlantic influence on spring snowfall over the Alps in the past 150 years
NASA Astrophysics Data System (ADS)
Global warming is believed to be responsible for the reduction of snow amount and duration over the Alps. In fact, a rapid shortening of the snowy season has been measured and perceived by ecosystems and society in the past 30 years, despite the large year-to-year variability. This trend is projected to continue during the 21st century in the climate change scenarios with increasing greenhouse gas concentrations. Superimposed on the long-term trend, however, there is a low-frequency variability of snowfall associated with multi-decadal changes in the large-scale circulation. The amplitude of this natural low-frequency variation might be relatively large, determining rapid and substantial changes of snowfall, as recently observed. This is already known for winter snowfall over the Alps in connection with the recent tendency toward the positive phase of the North Atlantic Oscillation. In this study, we show that the low-frequency variability of Alpine spring snowfall in the past 150 years is affected by the Atlantic Multi-decadal Oscillation (AMO), which is a natural periodic fluctuation of Northern Atlantic sea surface temperature. Therefore, the recently observed spring snowfall reduction might be, at least in part, explained by the shift toward a positive AMO phase that happened in the 1990s.
Zampieri, Matteo; Scoccimarro, Enrico; Gualdi, Silvio
Continuous Snowfall Replicator
A continuous snowfall replicator has been developed using the `roll-on' Formvar technique to apply a continuous strip of liquid Formvar to a 35-mm motion picture film base. Snow crystals which settle onto the moving strip are replicated upon Formvar hardening, producing a continuous sample. The replicas are viewed by either a 20� microfilm reader or a 50-100 � 35-mm projector.
Edward E. Hindman II; Robert L. Rinker
Oxygen isotopic variations of snowfall from winter storms in the central Sierra Nevada; Relation to ice growth microphysics and mesoscale structure
NASA Astrophysics Data System (ADS)
Observations have been made of the ice-crystal morphology of snow which fell at two sampling sites during a warm front followed by a cold front in the Sierra Nevada of the western United States. The snow sampling and ice crystal observations were conducted at Kingvale (KV) and Hobart Mills (HM), California, which are located at almost identical elevations on the upwind and down wind sides of the Sierra Nevada crest, respectively. These observations and several mesoscale features of one of the storms, have been used to study the substantial changes which occurred in the stable oxygen isotopic composition ( ?18O) of the precipitation at the two sites. At the beginning of the period of observation, a low level warm front lay across the region and its elevation lowered with time from 2.5 km to 1.7 km. This decrease of the frontal surface height was accompanied by a steady increase in the ?18O values. In the pre-cold frontal passage time periods, the ?18O values at the upwind site signified warmer origin ice crystal morphology than the downwind site. This is explained by orographic effects and the production of supercooled liquid water at low elevations on the upslope side of the Sierra Nevada. During the passage of the surface cold front, the differences in ?18O at the two sites were quite small probably because the orography plays a less significant role in the precipitation production process during such events. The ?18O peaked around -13% which translates to an "equivalent temperature" of -10.7�C for ice phase water capture at the upwind site KV. At site HM downwind of the Sierra crest, and 25 km east of KV, the weighted mean ice phase water capture occurred at elevations some 5 to 6�C colder than at KV, because of subsidence and loss of supercooled liquid water in the lower elevations on the lee side.
Warburton, Joseph A.; Demoz, Belay B.; Stone, Richard H.
An evaluation of the Wyoming gauge system for snowfall measurement
The Wyoming snow fence (shield) has been widely used with precipitation gauges for snowfall measurement at more than 25 locations in Alaska since the late 1970s. This gauge's measurements have been taken as the reference for correcting wind-induced gauge undercatch of snowfall in Alaska. Recently, this fence (shield) was tested in the World Meteorological Organization Solid Precipitation Measurement Intercomparison Project at four locations in the United States of America and Canada for six winter seasons. At the Intercomparison sites an octagonal vertical Double Fence with a Russian Tretyakov gauge or a Universal Belfort recording gauge was installed and used as the Intercomparison Reference (DFIR) to provide true snowfall amounts for this intercomparison experiment. The intercomparison data collected were compiled at the four sites that represent a variety of climate, terrain, and exposure. On the basis of these data sets the performance of the Wyoming gauge system for snowfall observations was carefully evaluated against the DFIR and snow cover data. The results show that (1) the mean snow catch efficiency of the Wyoming gauge compared with the DFIR is about 80-90%, (2) there exists a close linear relation between the measurements of the two gauge systems and this relation may serve as a transfer function to adjust the Wyoming gauge records to obtain an estimate of the true snowfall amount, (3) catch efficiency of the Wyoming gauge does not change with wind speed and temperature, and (4) Wyoming gauge measurements are generally compatible to the snowpack water equivalent at selected locations in northern Alaska. These results are important to our effort of determining true snowfall amounts in the high latitudes, and they are also useful for regional hydrologic and climatic analyses.
Yang, D.; Kane, D. L.; Hinzman, L. D.; Goodison, B. E.; Metcalfe, J. R.; Louie, P. Y. T.; Leavesley, G. H.; Emerson, D. G.; Hanson, C. L.
The North Atlantic Oscillation: Impact on Snowfall Conditions in the Northeastern U.S
NASA Astrophysics Data System (ADS)
The North Atlantic Oscillation (NAO) is one of the main components of atmospheric circulation variability within the middle and high latitudes of the Northern Hemisphere, particularly impacting winter weather patterns in northeastern United States. Previous research has indicated greater snowfall totals and higher frequency of snowfall days in the Northeast during a NAO negative phase due to repeated polar outbreaks; yet, the NAO positive phase has also been associated with extreme snowfall events in this region. This study examines the relationship between the NAO and winter (December - February) snowfall totals in northeastern U.S. between 1961 and 2010. Two case studies of recent winter events with differing NAO phases were evaluated to provide insight on how both NAO phases can produce significant snowfall in portions of the Northeast. The analysis revealed an inverse relationship between the NAO phase and seasonal snowfall, with positive (negative) NAO index years associated with lower (higher) average snowfall and snowfall days. Significantly greater snowfall during the NAO negative phase was mainly located along the East Coast as well as the interior southern half of the study region. A composite analysis of various tropospheric variables (e.g., 500-hPa heights) showed NAO negative years produced greater snowfall due to more extreme weather conditions affecting the Northeast, such as below normal sea level pressure, a deepened mid-tropospheric trough and weaker upper-level westerlies that permitted more frequent polar outbreaks. The intrusion of cold polar air into the interior U.S. generates more extreme temperature gradients and produces snowfall farther south than the NAO positive phase. In addition, the eastward displacement of the storms in the NAO negative phase along with the available moisture from the Atlantic Ocean creates more snowfall along the East Coast. These results correspond to the spatial distribution of snowfall that occurred during the February 2010 winter storms that produced significant snowfall throughout most of the Northeast, particularly around the mid-Atlantic. On the other hand, stations indicating no relationship between NAO and snowfall were mainly located in western and central New York, northern Vermont, and Maine. These regions of the Northeast correspond to those that receive snowfall in either NAO phase, as exhibited in the case studies, due to the effects of nearby lakes and higher terrain related to the storm tracks through these areas. Winter storms track over this northern region (of the Northeast) regardless of NAO phase whereas snowfall in the mid-Atlantic states is more dependent on a strong southerly track (i.e. Cape Hatteras/Nor'easter low) associated with the NAO negative phase. Since western New York and northwestern Pennsylvania border Lake Ontario and Lake Erie, the stations in these regions commonly receive lake-effect snow as a result of great fetch due to the west-east orientation of both lakes. Stations in central and northern New York receive lake-effect snow as additional lift is generated when the moist air reaches the Allegheny Plateau and the Adirondack Mountains.
Budikova, D.; Widen, H.; Coleman, J. S.
Climatological characterization of wind and snowfall in Minnesota and assessing the impacts of living snow fences
NASA Astrophysics Data System (ADS)
Blowing and drifting snow on roadways is a common occurrence in Minnesota due to the topographic, vegetative, and winter climate characteristics of this area. Through proper road design and the use of snow fences this problem can be alleviated, however snowfall and wind climatological information must first be analyzed. Archived climatological records for locations in Minnesota were recently compiled. Snowfall time series data show a statistically significant increase of 28cm in the annual total since 1890. The increase is shown to occur for November--December while February and March show a decrease. This increase is largely due to an increase in the frequency of snow events less than 10cm. Wind data from federal observing sites in Minnesota show a correlation to landscape variability, with a high frequency of higher wind speeds in western and southern Minnesota. A snow relocation factor needed to quantify seasonal snow transport was calculated and shows a strong dependence on the wind speed distribution. A case study of the 2000--01 winter season allowed for examination of snow storage and agricultural implications of three living snow fence designs in southern Minnesota (two 8-row strips of corn, twin-row honeysuckle, single-row honeysuckle/red cedar). For a winter with high seasonal snowfall and spring rainfall, results of snow storage and modeled seasonal snow transport show good agreement for the two corn row strips. However, snow storage totaled approximately 50% of the modeled snow transport for the honeysuckle fence designs, which appeared to reach storage capacity prior to the end of the snow season. A key factor is the absence of a bottom gap, which promotes leeward displacement of the downwind drift and prevents snow deposition on the fence. Soil temperature and frost depth data show a moderation in temperatures and a decrease in freezing depth with an increase in associated snowpack depth. Post-season soil moisture shows no significant variability with respect to over-winter snowpack due to the anomalous rainfall received during and after snowmelt. Finally, crop yield samples show a 6%--36% reduction adjacent to the fence, but also show a relatively quick recovery.
Shulski, Martha Elizabeth Durr
Elemental concentrations in fresh snowfall across a regional transect in the northeastern U.S.: Apparent sources and contribution to acidity
Fresh snowfall was collected on the surface of 8 lakes across a 350 km west-east transect from northeastern New York state to the coast of Maine after a single storm. In addition, every snowfall event during the winter of 1993 was collected on a single lake near the center of the transect. Across the transect, midwestern sources appear to dominate
W. Troy Baisden; Joel D. Bluh; Eric K. Miller; Andrew J. Friedland
A Large-Droplet Mode and Prognostic Number Concentration of Cloud Droplets in the Colorado State University Regional Atmospheric Modeling System (RAMS). Part II: Sensitivity to a Colorado Winter Snowfall Event.
NASA Astrophysics Data System (ADS)
This paper is the second in a two-part series describing recent additions to the microphysics module of the Regional Atmospheric Modeling System (RAMS) at Colorado State University. These changes include the addition of a large-cloud-droplet mode (40 80 ?m in diameter) into the liquid-droplet spectrum and the parameterization of cloud-droplet nucleation through activation of cloud condensation nuclei (CCN) and giant CCN (GCCN). The large-droplet mode was introduced to represent more precisely the natural dual mode of the cloud-droplet distribution. The parameterized droplet nucleation replaces the former estimation of cloud-droplet formation solely from supersaturation calculations. In Part I of this series, details of the improvements to the microphysics were presented, including the set of equations governing the development of cloud droplets in the Lagrangian parcel model that was employed to parameterize this complex process. Supercell simulations were examined with respect to the model sensitivity to the presence and concentration of large cloud droplets, CCN, and GCCN. Part II examines the sensitivity of the model microphysics to imposed aerosol variations in a wintertime snowfall event that occurred over Colorado on 28 29 February 2004. Model analyses and sensitivity are compared with the real-time forecast version 4.3 of RAMS as well as selected snowpack telemetry (SNOTEL) accumulated precipitation data and surface data from Storm Peak Laboratory in Steamboat Springs, Colorado.
Saleeby, Stephen M.; Cotton, William R.
On the future reduction of snowfall in western and central Europe
NASA Astrophysics Data System (ADS)
Large parts of western and central Europe face a 20-50 % future reduction in snowfall on Hellmann days (days with daily-mean temperatures below freezing). This strong reduction occurs in addition to the expected 75 % decrease of the number of Hellmann days near the end of the twenty first century. The result is insensitive to the exact freezing-level threshold, but is in sharp contrast with the winter daily precipitation, which increases under most global warming scenarios. Not only climate model simulations show this. Observational records also reveal that probabilities for precipitation on Hellmann days have been larger in the past. The future reduction is a consequence of the freezing-level threshold becoming a more extreme quantile of the temperature distribution in the future. Only certain circulation types permit these quantiles to be reached, and it is shown that these have intrinsically low precipitation probability.
de Vries, Hylke; Haarsma, Reindert J.; Hazeleger, Wilco
Polarization lidar liquid cloud detection algorithm for winter mountain storms
NASA Technical Reports Server (NTRS)
We have collected an extensive polarization lidar dataset from elevated sites in the Tushar Mountains of Utah in support of winter storm cloud seeding research and experiments. Our truck-mounted ruby lidar collected zenith, dual-polarization lidar data through a roof window equipped with a wiper system to prevent snowfall accumulation. Lidar returns were collected at a rate of one shot every 1 to 5 min during declared storm periods over the 1985 and 1987 mid-Jan. to mid-Mar. Field seasons. The mid-barrier remote sensor field site was located at 2.57 km MSL. Of chief interest to weather modification efforts are the heights of supercooled liquid water (SLW) clouds, which must be known to assess their 'seedability' (i.e., temperature and height suitability for artificially increasing snowfall). We are currently re-examining out entire dataset to determine the climatological properties of SLW clouds in winter storms using an autonomous computer algorithm.
Sassen, Kenneth; Zhao, Hongjie
Microbial response to increasing temperatures during winter in arable soils
NASA Astrophysics Data System (ADS)
Climate scenarios predict increasing temperatures and higher precipitation rates in late fall to early spring, both holding the potential to modify carbon and nutrient dynamics in soils by altering snow pack thickness and soil frost events. When soils are frozen, a small amount of unfrozen water allows microorganisms to remain active at temperatures down to -10 �C. We carried out a field experiment on the microbial use of maize straw. We compared soils of two different clay contents and used latitude as a proxy for climate. Microcosms with sieved soil were mixed with chopped maize leaf straw (C/N 17) at a rate of 1 mg C g-1 dry soil, un-amended microcosms served as control. Results indicated that C-mineralization rates were independent from clay content. However, the microbial use of maize derived nitrogen was only increased in the soil with 13% clay compared to 33% clay in the other soil. Microbial responses to climate changes can be expected to be very specific due to characteristics of the soil and/or the location.
Lukas, Stefan; Potthoff, Martin; Joergensen, Rainer Georg
Production System Techniques to Increase Nitrogen Use Efficiency in Winter Wheat
Most current research on winter wheat (Triticum aestivum L.) focuses on increasing yields of either grain or plant biomass. Increased production costs and environmental awareness will promote the development of methods to increase the efficiency of applied nutrients. Nitrogen (N) is often the most limiting nutrient for cereal grain production and represents one of the highest input costs in agricultural
W. E. Thomason; W. R. Raun; G. V. Johnson; K. W. Freeman; K. J. Wynn; R. W. Mullen
Cold temperature increases winter fruit removal rate of a bird-dispersed shrub.
Kwit, C., D. J. Levey; C. H. Greenberg, S. F. Pearson, J.P. McCarty, and S. Sargent. Cold temperature increases winter fruit removal rate of a bird-dispersed shrub. Oecologia. 139:30-34. Abstract: We tested the hypothesis that winter removal rates of fruits of wax myrtle, Myrica cerifera, are higher in colder winters. Over a 9-year period, we monitored M. cerifera fruit crops in 13 0.1-ha study plots in South Carolina, U.S.A. Peak ripeness occurred in November, whereas peak removal occurred in the coldest months, December and January. Mean time to fruit removal within study plots was positively correlated with mean winter temperatures, thereby supporting our hypothesis. This result, combined with the generally low availability of winter arthropods, suggests that fruit abundance may play a role in determining winter survivorship and distribution of permanent resident and short-distance migrant birds. From the plant's perspective, it demonstrates inter-annual variation in the temporal component of seed dispersal, with possible consequences for post-dispersal seed and seedling ecology.
Charles Kwit; Douglas J. Levey; Cathryn H. Greenberg; Scott F. Pearson; John P. McCarty; Sarah Sargent
A shorter snowfall season associated with higher air temperatures over northern Eurasia
NASA Astrophysics Data System (ADS)
The temperature sensitivity of the snowfall season (start, end, duration) over northern Eurasia (the former USSR) is analyzed from synoptic records of 547 stations from 1966 to 2000. The results find significant correlations between temperature and snowfall season at approximately 56% of stations (61% for the starting date and 56% for the ending date) with a mean snowfall season duration temperature sensitivity of -6.2 days �C-1 split over the start (2.8 days) and end periods (-3.4 days). Temperature sensitivity was observed to increase with stations� mean seasonal air temperature, with the strongest relationships at locations of around 6?�C temperature. This implies that increasing air temperature in fall and spring will delay the onset and hasten the end of snowfall events, and reduces the snowfall season length by 6.2 days for each degree of increase. This study also clarifies that the increasing trend in snowfall season length during 1936/37-1994 over northern European Russia and central Siberia revealed in an earlier study is unlikely to be associated with warming in spring and fall seasons.
Ye, Hengchun; Cohen, Judah
Spatial Variability of alpine snowfall and snow accumulation from radar and lidar data
NASA Astrophysics Data System (ADS)
A mobile polarimetric X-band radar (MXPol) deployed in the area of Davos (Switzerland) collected valuable and continuous information on small-scale precipitation for the winter seasons of 2009/2010 and 2010/2011. These data are compared to local measurements of the maximum snow accumulation over the season collected with Airborne Laser Scanning (ALS) at the Wannengrat area (Davos, Switzerland). This unique configuration makes the comparison of the variability in snowfall (as seen by the radar) and in snow accumulation (from laser scans) possible over the entire winter seasons. The spatial variability, quantified by means of the variogram (related to autocorrelation), is shown to be larger in snow accumulation than in snowfall. This indicates that other factors (like wind and turbulence taking place close to the ground) induced by small-scale topographic features govern the snow deposition and accumulation at the ground level in mountainous areas. In order to further investigate this question, the domain covered by the radar is divided in two sub-domains over which the radar beam is either close or far from a mountain ridge. The variability in snowfall, as well as the turbulence intensity, appears consistently larger in the vicinity of the ridge than far from the ground, which confirms the influence of small-scale topography on snowfall.adar data snapshot from March 18, 2011 at 00:06:48 UTC. a) Reflectivity. b) Differential reflectivity. c) Doppler spectral width
Scipion, D. E.; Mott, R.; Lehning, M.; Berne, A.
21st century snowfall changes over the French Alps : the role of temperature
NASA Astrophysics Data System (ADS)
Mountainous areas are among the regions where particularly severe climate changes are expected to occur within the next century. Snowfall changes in those regions could have widespread hydrological, ecological and economic impacts. Fine topography influence on the local climate in those regions has to be taken into account to produce realistic climate projections, especially for precipitations. Within the recent SCAMPEI (Climate Scenarios for Mountain Areas : Extreme Events, Snow Cover and Uncertainties) project, dedicated to climate change over French mountainous areas, a very large ensemble of high-resolution regional climate projections has been analyzed. They were obtained either through statistical or dynamical downscaling. The statistical downscaling method is based on weather typing and is applied to 14 models from the Coupled Model Intercomparison Project 3 and to a set of projections from the atmospheric global circulation model of M�t�o-France, to reach a horizontal resolution of 8km over France. High resolution regional climate projections come from three specific models at 12km used in SCAMPEI and also from 16 models from the ENSEMBLES European project (at a 25km horizontal resolution over Europe). An evaluation of the robustness of snowfall changes over the French Alps simulated during the 21st century and the associated uncertainties will be presented. In particular, the role of temperature changes on snowfall changes will be discussed. At the beginning and at the end of the cold season, temperature change is found to be an important source of spread in snowfall changes. However, no link is found between temperature and snowfall changes in January and February. For early and late winter, the relative change in snowfall per degree Kelvin is a robust quantity in the sense that its sensitivity to the bias correction step, the projection period or the greenhouse gas emission scenario is low.
Piazza, M.; Boe, J.; Page, C.; Sanchez-Gomez, E.; Terray, L.
Effects of Snowfall on Drifting Snow and Wind Structure Near a Surface
NASA Astrophysics Data System (ADS)
Wind-tunnel and numerical experiments were performed to investigate the effects of snowfall on the wind profile and the development of drifting snow. Wind profiles and mass-flux profiles of drifting snow were measured with and without artificial snowfall over a snow surface within the tunnel. Wind and shear-stress profiles and the impact speeds of the snowflakes during snowfall were also investigated numerically. During snowfall, snowflakes transfer part of their horizontal momentum to the air, which increases the stress close to the snow surface; however, the resultant modifications of the wind profiles are small. Because snowflakes have large momentum, the decomposed snow crystals that result from their collision with a surface can form a saltation layer, even over a hard snow surface where entrainment of the grains from the surface does not occur. Additionally, during snowfall, the threshold friction velocity can be lower than the impact threshold because snowflake fragmentation facilitates snow drifting. The broken crystals contribute to the increase in the number of drifting snow grains, even below the impact threshold.
Nemoto, Masaki; Sato, Takeshi; Kosugi, Kenji; Mochizuki, Shigeto
The criteria of heavy snowfalls in Russia
NASA Astrophysics Data System (ADS)
Nowadays, unfortunately, the number of victims of natural hazards doesn't decrease in Russia. There are many reasons of that situation - both geographical and human. Russia is one of the most spread countries in the world and it has the big number of different types of natural phenomena, which can cause natural disaster. One of the reasons is the fact that the criteria of which meteorological or hydrological hazards can cause an emergency situation are equal for the whole territory of Russia. .And that's why many dangerous situations are underestimated. The analysis of the distribution of criteria in Russia shows that only temperature phenomena (such as frost or heat) have really space differentiation. According to directive documents in Russia, the criteria of heavy snowfall in all the territory of Russia is 20 mm per 12 hours - from subtropical to arctic regions. But the socio-economical and climatic conditions are so different, that using this one criteria is not rational at all. In the investigation held the author developed the method of differentiation the territoty of Russia and proposed different criteria of heavy snowfalls for chosen regions. The method is based, on one hand on analysis of 30-years statistics of natural disasters in Russia, and on other hand on the analysis of the density of population and the mean quantity of precipitation in the cold period in Russia. The geographical zoning of Russia was conduct and clusters with equal parameters were determined. That means that in these areas the same hydro meteorological characteristics can be used for. The new criteria for the number of natural phenomena (such as hale, snowfalls etc) were found. The analysis of this criteria of heavy snowfalls showed, that on 70 the territory of Russia this criteria (20 mm per 12 hours) is overstated. In the most of the big cities (according to the statistics and calculated data) in different climatic regions this criteria should be much lower - from 8 to 10 mm per 12 hours.
Gavrilova, Sofia
TOMS observations of increases in Asian aerosol in winter from 1979 to 2000
NASA Astrophysics Data System (ADS)
Emission inventories indicate that the largest increases in SO2 emissions have occurred in Asia during the last 20 years. By inference, largest increases in aerosol, produced primarily by the conversion of SO2 to sulfate, should have occurred in Asia during the same time period. Decadal changes in regional aerosol optical depths are calculated by analyzing Total Ozone Mapping Spectrometer (TOMS) vertical aerosol optical depths (converted to 550 nm) from 1979 to 2000 on a 1 degree by 1 degree global grid. Aerosol trends are calculated on a regional basis during winter (November - February) to maximize the anthropogenic component of the aerosol record. Largest increases in aerosol optical depths between 1979 and 2000 are present over the China coastal plain and the Ganges river basin in India.
Massie, S. T.; Heymsfield, A. J.; Torres, O.; Smith, S.
Analysis of a snowfall event produced by mountains waves in Guadarrama Mountains (Spain)
NASA Astrophysics Data System (ADS)
Heavy snowfall events are fairly uncommon precipitation processes in the Iberian Peninsula. When large amounts of snow accumulate in large cities with populations that are unaccustomed to or unprepared for heavy snow, these events have a major impact on their daily activities. On 16 January 2013, an extreme snowstorm occurred in Guadarrama Mountains (Madrid, Spain) during an experimental winter campaign as a part of the TECOAGUA Project. Strong northwesterly winds, high precipitation and temperatures close to 0�C were detected throughout the whole day. During this episode, it was possible to continuously take measurements of different variables involved in the development of the convection using a multichannel microwave radiometer (MMWR). The significant increase in the cloud thickness observed vertically by the MMWR and registered precipitation of 43 mm in 24 hours at the station of Navacerrada (Madrid) led us to consider that we were facing an episode of strong winter convection. Images from the Meteosat Second Generation (MSG) satellite suggested that the main source of the convection was the formation of mountain waves on the south face of the Guadarrama Mountains. The event was simulated in high resolution using the WRF mesoscale model, an analysis of which is based on the observational simulations and data. Finally, the continuous measurements obtained with the MMWR allowed us to monitor the vertical situation above the Guadarrama Mountains with temporal resolution of 2 minutes. This instrument has a clear advantage in monitoring short-term episodes of this kind in comparison to radiosondes, which usually produce data at 0000 and 1200 UTC. Acknowledgements This study was supported by the following grants: GRANIMETRO (CGL2010-15930); MICROMETEO (IPT-310000-2010-22). The authors would like to thank the Regional Government of Castile-Le�n for its financial support through the project LE220A11-2.
Gasc�n, Est�baliz; S�nchez, Jos� Luis; Fern�ndez-Gonz�lez, Sergio; Merino, Andr�s; L�pez, Laura; Garc�a-Ortega, Eduardo
Winter climate variability changes over Europe and the Mediterranean region under increased greenhouse conditions
NASA Astrophysics Data System (ADS)
Regional changes in seasonal precipitation over Europe have been analysed in two 30-year simulations (current climate and A2-SRES increased greenhouse-gases scenario) using a Global (GCM) and a Regional Climate Model (RCM). The analysis of the simulations is approached using maximum covariance analysis (MCA) to establish the relationship between seasonal precipitation over the European-Mediterranean region and the North Atlantic atmospheric patterns in the winter season. Our results show that the leading MCA modes in the control simulation are similar for both models and agree well with previous studies using observations. The analysis of the A2-SRES scenario RCM results show changes with respect to the control simulation: the first two modes present slight shifts in their centres of action, whereas the third mode resembles more closely what is obtained in current climate simulations. Some differences, specially for the third mode, are obtained when comparing the RCM and the GCM simulations.
Rodr�guez-Fonseca, B.; S�nchez, E.; Arribas, A.
Synoptic controls on upper Colorado River basin snowfall
Synoptic controls of the Colorado River basin snowfall are determined from 700 mb atmospheric circulation. The 700 mb time series is run through an S-mode Principal Component Analysis (PCA) which creates a synoptic index over the western US region This synoptic index is used as input to a feed-forward backpropagation neural network to develop transfer functions that simulate daily snowfall
David L. McGinnis
Climatic Warming Increases Winter Wheat Yield but Reduces Grain Nitrogen Concentration in East China
Climatic warming is often predicted to reduce wheat yield and grain quality in China. However, direct evidence is still lacking. We conducted a three-year experiment with a Free Air Temperature Increase (FATI) facility to examine the responses of winter wheat growth and plant N accumulation to a moderate temperature increase of 1.5�C predicted to prevail by 2050 in East China. Three warming treatments (AW: all-day warming; DW: daytime warming; NW: nighttime warming) were applied for an entire growth period. Consistent warming effects on wheat plant were recorded across the experimental years. An increase of ca. 1.5�C in daily, daytime and nighttime mean temperatures shortened the length of pre-anthesis period averagely by 12.7, 8.3 and 10.7 d (P<0.05), respectively, but had no significant impact on the length of the post-anthesis period. Warming did not significantly alter the aboveground biomass production, but the grain yield was 16.3, 18.1 and 19.6% (P<0.05) higher in the AW, DW and NW plots than the non-warmed plot, respectively. Warming also significantly increased plant N uptake and total biomass N accumulation. However, warming significantly reduced grain N concentrations while increased N concentrations in the leaves and stems. Together, our results demonstrate differential impacts of warming on the depositions of grain starch and protein, highlighting the needs to further understand the mechanisms that underlie warming impacts on plant C and N metabolism in wheat.
Deng, Aixing; Song, Zhenwei; Zhang, Baoming; Zhang, Weijian
Review of Snow Conditions and Winter Climate Near Burlington and Underhill, Vermont.
National Technical Information Service (NTIS)
The review provides information on the winter environment near Camp Ethan Allen in northeastern Vermont. In particular, monthly summaries of the frequency, intensity, and water content of snowfall events are presented. Additional information on air-temper...
M. A. Bilello
Elevated streamflows increase dam passage by juvenile coho salmon during winter: Implications of climate change in the Pacific Northwest
A 4-year evaluation was conducted to determine the proportion of juvenile coho salmon Oncorhynchus kisutch passing Cowlitz Falls Dam, on the Cowlitz River, Washington, during winter. River and reservoir populations of coho salmon parr were monitored using radiotelemetry to determine if streamflow increases resulted in increased downstream movement and dam passage. This was of interest because fish that pass downstream of Cowlitz Falls Dam become landlocked in Riffe Lake and are lost to the anadromous population. Higher proportions of reservoir-released fish (0.391-0.480) passed Cowlitz Falls Dam than did river-released fish (0.037-0.119). Event-time analyses demonstrated that streamflow increases were important predictors of dam passage rates during the study. The estimated effect of increasing streamflows on the risk of dam passage varied annually and ranged from 9% to 75% for every 28.3 m3/s increase in streamflow. These results have current management implications because they demonstrate the significance of dam passage by juvenile coho salmon during winter months when juvenile fish collection facilities are typically not operating. The results also have future management implications because climate change predictions suggest that peak streamflow timing for many watersheds in the Pacific Northwest will shift from late spring and early summer to winter. Increased occurrence of intense winter flood events is also expected. Our results demonstrate that juvenile coho salmon respond readily to streamflow increases and initiate downstream movements during winter months, which could result in increased passage at dams during these periods if climate change predictions are realized in the coming decades.
Kock, Tobias J.; Liedtke, Theresa L.; Rondorf, Dennis W.; Serl, John D.; Kohn, Mike; Bumbaco, Karin A.
Impact of declining Arctic sea ice on northern hemisphere winter weather
NASA Astrophysics Data System (ADS)
Judith Curry and Jiping Liu. An overview is provided of our recent paper that linked the decrease in autumn Arctic sea ice to changes in the winter Northern Hemispher atmospheric circulation that results in more frequent episodes of blocking patterns that lead to increased cold surges over large parts of northern continents. Moreover, the increase in atmospheric water vapor content in the Arctic region during late autumn and winter driven locally by the reduction of sea ice provides enhanced moisture sources, supporting increased regional heavy snowfalls. An analysis is provided of the last three winters. The need for a satellite-based assessment of cold-season open water surface sensible and latent heat fluxes is discussed.
Curry, J. A.; Liu, J.
Dissolved organic matter composition of winter flow in the Yukon River basin: Implications of permafrost thaw and increased groundwater discharge
NASA Astrophysics Data System (ADS)
Groundwater discharge to rivers has increased in recent decades across the circumpolar region and has been attributed to thawing permafrost in arctic and subarctic watersheds. Permafrost-driven changes in groundwater discharge will alter the flux of dissolved organic carbon (DOC) in rivers, yet little is known about the chemical composition and reactivity of dissolved organic matter (DOM) of groundwater in permafrost settings. Here, we characterize DOM composition of winter flow in 60 rivers and streams of the Yukon River basin to evaluate the biogeochemical consequences of enhanced groundwater discharge associated with permafrost thaw. DOC concentration of winter flow averaged 3.9 � 0.5 mg C L-1, yet was highly variable across basins (ranging from <1 to >20 mg C L-1). In comparison to the summer-autumn period, DOM composition of winter flow had lower aromaticity (as indicated by specific ultraviolet absorbance at 254 nm, or SUVA254), lower hydrophobic acid content, and a higher proportion of hydrophilic compounds (HPI). Fluorescence spectroscopy and parallel factor analysis indicated enrichment of protein-like fluorophores in some, but not all, winter flow samples. The ratio of DOC to dissolved organic nitrogen, an indicator of DOM biodegradability, was positively correlated with SUVA254 and negatively correlated with the percentage of protein-like compounds. Using a simple two-pool mixing model, we evaluate possible changes in DOM during the summer-autumn period across a range of conditions reflecting possible increases in groundwater discharge. Across three watersheds, we consistently observed decreases in DOC concentration and SUVA254 and increases in HPI with increasing groundwater discharge. Spatial patterns in DOM composition of winter flow appear to reflect differences in the relative contributions of groundwater from suprapermafrost and subpermafrost aquifers across watersheds. Our findings call for more explicit consideration of DOC loss and stabilization pathways associated with changing subsurface hydrology in watersheds underlain by thawing permafrost.
O'Donnell, Jonathan A.; Aiken, George R.; Walvoord, Michelle A.; Butler, Kenna D.
Integrating snowfall limit forecasts to improve hydrological modeling
NASA Astrophysics Data System (ADS)
Flood forecasting in mountainous areas requires accurate partitioning between rain and snowfall; an incorrect snow/rainfall limit (on daily or sub-daily timescales) typically implies a significant over- (or under-)estimation of the source catchment areas contributing to runoff and infiltration. This study details the development of a snow/rainfall partitioning method which incorporates snowfall limit information from Limited Area Models (LAMs) to improve catchment-scale hydrological modeling. LAMs consider the vertical, humid, atmospheric structure including wet bulb temperature in their snowfall limit calculations. Such an approach is more physically-based than inferring snowfall limit estimates based on dry, ground temperature measurements, which is the standard procedure in most hydrological models. A case study involving complex topography in the Swiss Alps demonstrates the potential of the developed method with the integration of COSMO forecast re-analysis snowfall limit information. Such data and the new method are proven here to significantly improve runoff simulation, particularly in the spring when a large part of the catchment is close to saturation. Integrating LAM snowfall limits thereby provides good estimates of runoff contributing areas, with practical implications for operational hydrology in Alpine regions.
Tobin, C.; Rinaldo, A.; Schaefli, B.
Cross Validation of Spaceborne and Ground Polarimetric Radar Snowfall Retrievals
NASA Astrophysics Data System (ADS)
Snow, as a primary contribution to regional or even global water budgets is of critical importance to our society. For large-scale weather monitoring and global climate studies, satellite-based snowfall observations with ground validations have become highly desirable. Ground-based polarimetric weather radar is the powerful validation tool that provides physical insight into the development and interpretation of spaceborne snowfall retrievals. This study aims to compare and resolve discrepancies in snowfall detection and estimation between Cloud Profiling Radar (CPR) on board NASA's Cloudsat satellite and new polarimetric National Mosaic and Multi-sensor QPE (NMQ) system (Q3) developed by OU and NOAA/NSSL scientists. The Global Precipitation Measurement Mission with its core satellite scheduled for launch in 2014 will carry active and passive microwave instrumentation anticipated to detect and estimate snowfall or snowpack. This study will potentially serve as the basis for global validation of space-based snowfall products and also invite synergistic development of coordinated space-ground multisensor snowfall products.
Wen, Y.; Hong, Y.; Cao, Q.; Kirstetter, P.; Gourley, J. J.; Zhang, J.
Water relations and mucopolysaccharide increases for a winter hardy cactus during acclimation to subzero temperatures
Thickness, relative water content (RWC), osmotic pressure, water potential isotherms, and mucopolysaccharide content were measured for the photosynthetic chlorenchyma and the water-storage parenchyma of the winter hardy cactus, Opuntia humifusa, after shifting from day\\/night air temperatures of 25� C\\/15� C to 5� C\\/-5� C. After 14 d at 5� C\\/-5� C, the average fraction of water contained in the symplast
Michael E. Loik; Park S. Nobel
Observations and Modeling of Winter Storms in the Himalayas
NASA Astrophysics Data System (ADS)
Based on observations from a hydrometeorological network on the eastern slopes of the Annapurna Range, the summer monsoon (June-September) is responsible for 80-90% of annual precipitation at low elevations (< 2000 m MSL) in Nepal, with nearly all of it in liquid form even during the winter. However, high elevations can receive up to 25% of their annual precipitation as snowfall during the winter, with the percentage of the annual total an increasing function of elevation. Significant snowstorms often are associated with terrain-locked low-pressure systems that form when an upper-level disturbance passes over the notch formed by the Himalayas and Hindu Kush mountains. These systems cause deep upslope flow over central Nepal, resulting in orographic precipitation. Notable case studies for three winters (January-March 2000-2002) are reviewed using local precipitation (snow and rain) and other meteorological data, as well as satellite (Meteosat-5 and TRMM) and NCEP/NCAR Reanalysis data. Based on these results, a 15-year (1988-2002) climatology is developed and interannual variability of winter storms is diagnosed. Finally, a cloud-resolving model with realistic topography is used to investigate mechanisms for controlling the spatial and temporal variability of precipitation during winter storms.
Lang, T. J.; Barros, A. P.
Additive Effects of Warming and Increased Nitrogen Deposition in a Temperate Old Field: Plant Productivity and the Importance of Winter
Both climate warming and atmospheric nitrogen (N) deposition are predicted to alter plant productivity and species composition\\u000a over the next century. However, the extent to which their effects may interact is unclear. For example, over winter, the effects\\u000a of warming on soil freezing dynamics may promote ecosystem N losses, thereby limiting increases in productivity in response\\u000a to warming, yet these
Jennifer S. Hutchison; Hugh A. L. Henry
The potential of five winter-grown crops to reduce root-knot nematode damage and increase yield of tomato.
Broccoli (Brassica oleracea), carrot (Daucus carota), marigold (Tagetes patula), nematode-resistant tomato (Solanum lycopersicum), and strawberry (Fragaria ananassa) were grown for three years during the winter in a root-knot nematode (Meloidogyne incognita) infested field in Southern California. Each year in the spring, the tops of all crops were shredded and incorporated in the soil. Amendment with poultry litter was included as a sub-treatment. The soil was then covered with clear plastic for six weeks and M. incognita-susceptible tomato was grown during the summer season. Plastic tarping raised the average soil temperature at 13 cm depth by 7�C.The different winter-grown crops or the poultry litter did not affect M. incognita soil population levels. However, root galling on summer tomato was reduced by 36%, and tomato yields increased by 19% after incorporating broccoli compared to the fallow control. This crop also produced the highest amount of biomass of the five winter-grown crops. Over the three-year trial period, poultry litter increased tomato yields, but did not affect root galling caused by M. incognita. We conclude that cultivation followed by soil incorporation of broccoli reduced M. incognita damage to tomato. This effect is possibly due to delaying or preventing a portion of the nematodes to reach the host roots. We also observed that M. incognita populations did not increase under a host crop during the cool season when soil temperatures remained low (< 18�C). PMID:22736848
L�pez-P�rez, Jose Antonio; Roubtsova, Tatiana; de Cara Garc�a, Miguel; Ploeg, Antoon
Winter peaks of methylmercury in deposition to a remote Scottish mountain lake.
Depositional records of methylmercury (MeHg) are rare, especially for remote and mountainous areas. Our data from Lochnagar, a mountain lake in Scotland, covering a 7-year period from 2001-2008, show an unusual seasonal pattern in that elevated MeHg concentrations occur each winter while concentrations each summer fall below the limit of detection. To our knowledge this is the first time this seasonal pattern has been reported. Peak concentrations at the site in October 2006 (1.2 ng L(-1)) are amongst the highest reported depositional values in the literature. As the soils and lakes in the region are frozen or snow covered for much of each winter, we consider possible sources of this winter deposited MeHg to be either aqueous phase methylation in the atmosphere or marine evasion. However, the factor driving this seasonal pattern is likely to be scavenging by snow, as elevated concentrations in deposition coincide with periods of snowfall at the site. If this mechanism is correct, then predicted impacts of climate change, which will reduce annual snowfall at the site by between 50% and 100% by 2080, will effectively eliminate this input source. However, other climate-influenced inputs of mercury, such as remobilisation from catchment soils, are likely to increase and negate any benefit. PMID:23123118
Rose, Neil L; Munthe, John; McCartney, Alistair
Winter storms in the central Himalayas
NASA Astrophysics Data System (ADS)
Based on observations from a hydrometeorological network in the Marsyandi river basin, on the eastern slopes of the Annapurna Range, the summer monsoon (June-September) is responsible for 80-90% of annual precipitation at low elevations (< 2000 m MSL) in central Nepal, with nearly all of it in liquid form even during the winter. However, high elevations (> 3000 m MSL) can receive up to 25-35% of their annual precipitation as snowfall during the winter, with the percentage of the annual total an increasing function of elevation. Major snowstorms are associated with terrain-locked low-pressure systems that form when upper-level disturbances (the so-called Western Disturbances) pass over the notch formed by the Himalayas and Hindu Kush mountains, causing upper-level SW flow over central Nepal and orographically forced precipitation. Notable case studies for three winters (January-March 2000-2002) are reviewed using local precipitation (snow and rain) and other meteorological data, as well as satellite (Meteosat-5 and TRMM) and NCEP/NCAR Reanalysis data. A 30-year (1973-2002) climatology of �notch� depressions reveals that winter storms in the central Himalayas are characterized by strong inter-annual variability, which cannot be explained based on known modes of climate variability (e.g., ENSO, NAO, etc). Finally, a cloud-resolving model with realistic topography is used to investigate mechanisms for controlling the spatial and temporal variability of precipitation during typical winter storms. The results indicate that precipitation occurs in the central Himalayas only when the large-scale circulation evolves to a spatial configuration that favors orographic precipitation processes. In addition, westerly-propagating along-barrier precipitation features fed by an easterly barrier jet apparently play an important role in bringing precipitation to lower elevations.
Barros, A.; Lang, T.
Iron-Superoxide Dismutase Expression in Transgenic Alfalfa Increases Winter Survival without a Detectable Increase in Photosynthetic Oxidative Stress Tolerance1
To determine whether overexpression of Fe-superoxide (SOD) dismutase would increase superoxide-scavenging capacity and thereby improve the winter survival of transgenic alfalfa (Medicago sativa L.) plants, two genotypes were transformed with the vector pEXSOD10, which contains a cDNA for Arabidopsis Fe-SOD with a chloroplast transit peptide and cauliflower mosaic virus 35S pro- moter. A novel Fe-SOD was detected by native PAGE
Bryan D. McKersie; Julia Murnaghan; Kim S. Jones; Stephen R. Bowley
Coupled Model Simulation of Snowfall Events Over the Black Hills
NASA Technical Reports Server (NTRS)
Although many long-term simulations of snow accumulation and oblation have been made using stand-alone land surface models and surface models coupled with GCMs, less research has focused on short-term event simulations. Actually, accurate event simulations of snow-related processes are the basis for successful long-term simulation. Three advantages of event simulations of snowfall and snow melting are availability of: (1) intensive observation data from field experiments for validation; (2) more physically-realistic precipitation schemes for use in atmospheric models to simulate snowfall; and (3) a more detailed analysis of the snow melting processes. In addition to the complexities of snow related processes themselves, terrain-induced effects on snowfall/snow melting make simulations of snow events more difficult. Climatological observations indicate that terrain features such as the Black Hills of South Dakota and Wyoming can exert important effects on snow accumulation and snow oblation processes. One of the primary effects is that the orography causes forced uplift of airflow and causes atmospheric waves to form both upwind and downwind of it. Airflow often splits around the obstacle, converging on the lee side. This convergence may lead to precipitation enhancement. It also provides an elevated heat and moisture source that enhances atmospheric instability. During the period of April 5-May 5, 1999, the Upper Missouri River Basin Pilot Project (UMRBPP) made intensive observations on precipitation events occurring in the Black Hills. Two moderate snowfall events were captured during the period. The resulting high temporal and spatial resolution data provides opportunities to investigate terrain effects on snowfall amount, distribution, and melting. Successful simulation of snowfall amount, distribution, and evolution using atmospheric models is important to subsequent modeling of snow melting using snow sub-models in land surface schemes. In this paper, a coupled model system, consisting of an atmosphere model (ARPS) and a land-surface model (revised NCAR LSM), is used to simulate one of these UMRBPP cases.
Wang, Jianzhong; Hjelmfelt, M. R.; Capehart, W. J.
Total Ozone Mapping Spectrometer (TOMS) observations of increases in Asian aerosol in winter from 1979 to 2000
Emission inventories indicate that the largest increases in SO{sub 2} emissions have occurred in Asia during the last 20 years. By inference, largest increases in aerosol, produced primarily by the conversion of SO{sub 2} to sulfate, should have occurred in Asia during the same time period. Decadal changes in regional aerosol optical depths are calculated by analyzing Total Ozone Mapping Spectrometer (TOMS) vertical aerosol optical depths (converted to 550 nm) from 1979 to 2000 on a 1{sup o} by 1{sup o} global grid. The anthropogenic component of the TOMS aerosol record is maximized by examining the seasonal cycles of desert dust and Boreal fire smoke, and identifying the months of the year for which the desert dust and Boreal fire smoke are least conspicuous. Gobi and Taklimakan desert dust in Asia is prevalent in the TOMS record during spring, and eastern Siberian smoke from Boreal forest fires is prevalent during summer. Aerosol trends are calculated on a regional basis during winter (November-February) to maximize the anthropogenic component of the aerosol record. Large increases in aerosol optical depths between 1979 and 2000 are present over the China coastal plain and the Ganges river basin in India. Aerosol increased by 17% per decade during winter over the China coastal plain, while SO{sub 2} emissions over the same geographical region increased by 33% per decade.
Massie, Steven T.; Torres, O.; Smith, Steven J.
Total Ozone Mapping Spectrometer (TOMS) observations of increases in Asian aerosol in winter from 1979 to 2000
NASA Astrophysics Data System (ADS)
Emission inventories indicate that the largest increases in SO2 emissions have occurred in Asia during the last 20 years. By inference, the largest increases in aerosol, produced primarily by the conversion of SO2 to sulfate, should have occurred in Asia during the same time period. Decadal changes in regional aerosol optical depths are calculated by analyzing Total Ozone Mapping Spectrometer (TOMS) vertical aerosol optical depths (converted to 550 nm) from 1979 to 2000 on a 1� by 1� global grid. The anthropogenic component of the TOMS aerosol record is maximized by examining the seasonal cycles of desert dust and boreal fire smoke and identifying the months of the year for which the desert dust and boreal fire smoke are least conspicuous. Gobi and Taklimakan desert dust in Asia is prevalent in the TOMS record during spring, and eastern Siberian smoke from boreal forest fires is prevalent during summer. Aerosol trends are calculated on a regional basis during winter (November-February) to maximize the anthropogenic component of the aerosol record. Large increases in aerosol optical depths between 1979 and 2000 are present over the China coastal plain and the Ganges River basin in India. Aerosol increased by 17% per decade during winter over the China coastal plain, while SO2 emissions over the same geographical region increased by 35% per decade.
Massie, Steven T.; Torres, Omar; Smith, Steven J.
Increased winter precipitation makes arctic tundra a methane source but gas diffusion modulates abiotic sensitivity of soil C efflux
NASA Astrophysics Data System (ADS)
Rapid climate warming in the Arctic is contributing to structural and functional changes in tundra ecosystems, possibly through increases in winter precipitation. Greater snow cover and higher surface temperatures in the Arctic are likely to expose C stored over millennia, leading to forcing feedbacks on the climate system through alterations in decomposition rates. However, greater winter snow cover is also likely to contribute to the expansion of shrubs into tundra ecosystems, affecting ecosystem productivity. Although potential increases in NPP may offset enhanced soil respiration rates, reduced redox conditions accompanying waterlogging may prompt methanogenic activity. Ecosystem CO2 and CH4 efflux and their soil profile concentrations were measured across a snow addition gradient experiment established in 1994 at Toolik Lake, AK. Our findings reveal important alterations of the CH4 production/consumption mechanisms in response to changes in snow cover. Stable isotope evidence suggests a shift in the dominant pathways contributing to the ecosystem CH4 emissions. Impaired methanotrophic activity was also observed linked to changes in the redox conditions throughout the soil column. Whereas CH4 emission rates were drastically increased under deeper snow cover, CO2 efflux response to the treatment resulted buffered despite the observed increases in soil temperature. Reduced diffusion coefficients (measured with 222Rn) may result in the apparent lack of temperature sensitivity in soil fluxes. Taken together, our results suggest that predicted changes in winter precipitation patterns and subsequent alterations in environmental variables have differing impact on CO2 and CH4 dynamics, and their contribution to ecosystem C efflux. Therefore, it is relevant to include these mechanisms in models predicting C feedbacks from permafrost-affected areas to the global climate system.
Blanc-Betes, E.; Thurnhoffer, B. M.; Gonzalez-Meler, M. A.; Sturchio, N. C.; Welker, J. M.
Variability and trends of total precipitation and snowfall over the United States and Canada
The biases and large-scale inhomogeneities in the time series of measured precipitation and snowfall over the United States and Canada are discussed and analyzed. The spatial statistical characteristics of monthly and annual snowfall and total precipitation are investigated and parameterized. After adjustments and selection of the best' network, reliable first guess' estimates of North American snowfall and precipitation are obtained.
Pavel Ya Groisman; David R. Easterling
Development and Application of a Regional Snowfall Impact Scale
NASA Astrophysics Data System (ADS)
This paper describes a new regional snowfall impact index that is being produced operationally on an experimental basis by NOAA�s National Climatic Data Center. The Regional Snowfall Impact Scale (ReSIS) is based on the spatial extent of the storm, the amount of snowfall, and the juxtaposition of these elements with population. Including population information ties the index to societal impacts. ReSIS is an evolution of the Northeast Snowfall Impact Scale (NESIS) which NCDC began producing operationally in 2005. While NESIS was developed for storms that had a major impact in the Northeast, it includes the impact of snow on other regions as well. It can be thought of as a quasi-national index that is calibrated to Northeast snowstorms. By contrast, ReSIS is a regional index; a separate index is produced for each of six climate regions in the eastern two-thirds of the nation. The purpose of this paper is to describe the methodology used to compute ReSIS, which requires region-specific parameters and thresholds. The process used to identify and select the region specific parameters is explained. The new index has been calculated for about 500 snowstorms that occurred between 1900 and 2010, including the 50 largest snowstorms in each of the six eastern climate regions. This allows ReSIS to put snowstorms into a century-scale historical perspective.
Lawrimore, J. H.; Squires, M. F.; Robinson, D. A.
Long-term continuous monitoring of mercury in the Russian arctic: winter increase of atmospheric mercury depletion events
NASA Astrophysics Data System (ADS)
Among pollutants mercury is a major environmental concern due to its ecological hazard. The mercury can reside in the atmosphere for a long time high, and it is a reason of its global propagation in the Northern Hemisphere and elevated mercury concentrations are reported in the Arctic environment. First time, in 1995, the effect of atmospheric mercury depletion in the troposphere was found at the Canadian station Alert. This phenomenon (called the Atmospheric Mercury Depletion Event - AMDE) is observed during April-June, when the Polar sunrise starts till the end of the snowmelt. The same effect was reported for other polar stations situated to the north of 60� N. Long-term continuous monitoring of gaseous elemental mercury in the surface air at the polar station Amderma (69,720N; 61,620E) using the analyzer Tekran 2537A has been conducted from Jun 2001 to date. Individual measurements were collected every thirty minutes. It has been shown, that during eleven years of observations the AMDEs were observed every year, from the end of March till early June. For the winter period (Dec-Feb) these events of the atmospheric mercury depletion were registered from 2010 to 2013, which had not been observed before. A large number of hours during the day, when the concentration of mercury was recorded at level of below 1 ng/m3, was registered during Dec-Feb. The sun declination above the horizon is negative, and solar activity is still not enough to trigger the photochemical reactions. The these last 3 years confirmed a tendency to displacement of AMDEs to the winter season, which leads to an additional factor entry of mercury in various biological objects, due to the additional deposition of various forms of mercury on the snowpack. At the same time, especially during the winter seasons, there is a substantial increase (up to 8 times) of AMDEs, compared with the previous years. In particular, in winter 2013 the maximum number of AMDs reached 31 cases. The explanation can be the following: the withdrawal of elemental mercury from the atmosphere may be caused by deposition of mercury on marine aerosol particles. Marine aerosol concentration increases in the case of exemption from coastal ice (Kara Sea) and, simultaneously, at the time when the northern wind direction is dominating. When the southern wind direction is prevailing, the deposition of mercury on anthropogenic aerosols transported from the middle latitudes is taken place. Acknowledgement - Financial support for the monitoring program was provided by Environment Canada, AMAP Secretariate and Russian Federal Service for Hydrometeorology and Environmental Monitoring.
Pankratov, Fidel; Mahura, Alexander; Popov, Valentin; Katz, Oleg
Hemispheric and Interannual Comparisons of Polar Winter CO2 Clouds on Mars
NASA Astrophysics Data System (ADS)
Polar carbon dioxide snow clouds contribute substantial material to the seasonal caps of Mars, in addition to direct surface frost formation. Snow clouds also affect the polar heat budget through two primary mechanisms: 1) snow particles decrease polar infrared emissivity during winter, and 2) fine-grained snow deposits increase solar albedo during summer. These effects can strongly alter the seasonal cap mass budget, and possibly explain the existence of the perennial CO2 deposits near the Martian south pole. Mapping the distribution and quantifying the abundance of CO2 snowfall therefore has important implications for the study of Mars' present-day climate. The phenomenon of condensing martian air is of course also interesting in its own right, from an atmospheric science perspective. We used data primarily from the Mars Climate Sounder (MCS) onboard the Mars Reconnaissance Orbiter to investigate the occurrence and properties (optical depth, particle size, altitude) of CO2 clouds in the winter polar regions. MCS retrieved temperature and aerosol opacity profiles now span four Mars years (MY28-MY31), allowing direct inter-annual comparisons for selected locations and seasons. Examples of observed inter-annual variability include decreased snowfall likely due to disruption of the northern polar vortex during the global dust storm of MY28. We also observe very distinct patterns of condensation in the northern and southern hemispheres, with cloud activity being much more intense in the northern hemisphere, but confined to higher latitudes, than in the south. Northern polar winter cloud activity is also distinctly bimodal in time, whereas southern winter cloud activity is evenly distributed over the winter season. In this presentation, we will present a summary of these observations and explore possible explanations for the variability in polar cloud phenomena.
Hayne, P. O.; Kleinboehl, A.; Heavens, N. G.; Paige, D. A.; Schofield, J. T.; Kass, D. M.; Shirley, J. H.; McCleese, D. J.
Estimating snowfall from temperature and precipitation in data-limited Himalayan watersheds
NASA Astrophysics Data System (ADS)
Climate change may affect the contribution of meltwater from snow and ice in the Himalayas to the great Asian rivers. Present contributions are reported to range from 10-20% of the annual discharge in the Ganges to 30-80% in the Indus. With few observations at higher elevations, the reality is that we do not know how much snow that is available for melting. To be able to understand the effect of future changes in climate, we need to know the present conditions, as well as how a change may be relevant for the parameters in question. In this study we have estimated 1) the amount of snow that falls over Himalaya/Hindukush/Karakoram today, and 2) in which parts of this region an increase in temperature alone may affect snowfall. There are few observations of weather and climate at higher elevations in the Himalayas, and even the annual precipitation varies greatly in the available gridded data sets. Aiming to estimate snowfall in the Indus, Ganges and Brahmaputra Basins, we thus combined several temperature and precipitation data sets in an ensemble. To be able to account for the diurnal cycle, we used the MERRA reanalysis as a basis, and then bias-corrected temperature and precipitation with data from CRU-TS, Aphrodite and TRMM, before calculating the amount of precipitation falling as snow every hour. The results deviate, with annual snowfall in one basin varying by a factor of 2-3, depending on the combination of input data. The spread is largely a result of precipitation differences, but temperature differences also affect the estimates. Whether an increase in temperature alone will influence snowfall and snowmelt, depends on the temperature in the region today. Regions where the temperature is currently near the freezing point, may be considered snow-critical. By finding the snow-critical range in each temperature data set, we have identified regions and elevations where the meltwater contribution is likely to be affected by a change in temperature. Any temperature increase in these regions will decrease the fraction of precipitation falling as snow, as well as increase snow- and ice-melt.
Viste, E.; Sorteberg, A.
Stable carbon isotopic ratios and ionic composition of the high-Arctic aerosols: An increase in ?13C values from winter to spring
Atmospheric particles were collected in the high Arctic at Alert during winter (February) and spring (April�May) and were subjected to stable carbon isotopic (?13C) measurements to better understand the source of carbonaceous aerosols. The mean ?13C values of aerosol total carbon (TC) were observed to increase from winter (?25.7 � 0.7�) to spring (?23.7 � 0.8�). A strong correlation (r2
M. Narukawa; K. Kawamura; S.-M. Li; J. W. Bottenheim
Evaluating the Performance of Single and Double Moment Microphysics Schemes During a Synoptic-Scale Snowfall Event
NASA Technical Reports Server (NTRS)
Increases in computing resources have allowed for the utilization of high-resolution weather forecast models capable of resolving cloud microphysical and precipitation processes among varying numbers of hydrometeor categories. Several microphysics schemes are currently available within the Weather Research and Forecasting (WRF) model, ranging from single-moment predictions of precipitation content to double-moment predictions that include a prediction of particle number concentrations. Each scheme incorporates several assumptions related to the size distribution, shape, and fall speed relationships of ice crystals in order to simulate cold-cloud processes and resulting precipitation. Field campaign data offer a means of evaluating the assumptions present within each scheme. The Canadian CloudSat/CALIPSO Validation Project (C3VP) represented collaboration among the CloudSat, CALIPSO, and NASA Global Precipitation Measurement mission communities, to observe cold season precipitation processes relevant to forecast model evaluation and the eventual development of satellite retrievals of cloud properties and precipitation rates. During the C3VP campaign, widespread snowfall occurred on 22 January 2007, sampled by aircraft and surface instrumentation that provided particle size distributions, ice water content, and fall speed estimations along with traditional surface measurements of temperature and precipitation. In this study, four single-moment and two double-moment microphysics schemes were utilized to generate hypothetical WRF forecasts of the event, with C3VP data used in evaluation of their varying assumptions. Schemes that incorporate flexibility in size distribution parameters and density assumptions are shown to be preferable to fixed constants, and that a double-moment representation of the snow category may be beneficial when representing the effects of aggregation. These results may guide forecast centers in optimal configurations of their forecast models for winter weather and identify best practices present within these various schemes.
Molthan, Andrew L.
Do CMIP5 models project increase or decrease in Pacific winter cyclone activity under global warming?
NASA Astrophysics Data System (ADS)
During the cool season, extratropical cyclones are responsible for much of the high impact weather, including high winds, heavy snow, coastal storm surge, and extreme precipitation events. Thus how cylone activity may change under global warming is of great concern to climate scientists and policy makers alike. With the availability of climate model simulations from multiple modeling centers under Phase 5 of the Coupled Model Intercomparison Project (CMIP5), several recent studies have examined how cyclone activity is projected to change under global warming. While the results of these studies generally agree that the total cyclone frequency is projected to decrease in the Northern Hemisphere, they disagree on how the frequency of deep cyclones may change. One study suggests that the frequency of deep cyclones will increase in the Pacific, while another study concludes that it will decrease significantly throughout the Northern Hemisphere, including over the North Pacific. This study seeks to assess why these two seemingly contradictory conclusions have been made based on CMIP5 data. A single tracking algorithm has been used to derive cyclone statistics from a multiple-model ensemble of 23 CMIP5 simulations based on two different definitions of what cyclones are. One definition treats cyclones as the minima in total sea level pressure (PSL), while the other definition considers cyclones as minima in PSL perturbations -- deviations of PSL from a large scale, low frequency background flow. Results of this study show that when cyclones are defined based on total PSL, the frequency of deep cyclones over the Pacific is projected to increase, while if cyclones are defined as perturbations, the frequency of deep cyclones is projected to decrease. The difference between these two results can be shown to be mainly due to a projected significant deepening of the Aleutian low under global warming. When the CMIP5 projected mean pressure change is added to historical PSL data, Pacific cyclones become much deeper, and tracking based on total PSL shows a large increase in deep cyclones, similar to what is found in the future projections. In view of these results, it is important to critically assess how cyclones should be defined.
Chang, E. K.
Snowfall Measurements in the Amundsen and Bellingshausen Seas, Antarctica
Unique in situ oceanic snowfall measurements in high southern latitudes are presented from two research cruises to the Ross, Amundsen, and Bellingshausen Seas aboard the R\\/V Nathaniel B. Palmer in 2007 (NBP0702 and NBP0709). The number of falling snowflakes passing through the beam of a photoelectric particle counter mounted approximately 30m above sea level was continuously logged during these cruises,
NSDL National Science Digital Library
Contrary to what many people think, Fall is the time of year when your turf needs attention. The following three steps need to be completed before the first snowfall: Apply Fertilizer Lower Mower Height Drain Secondary Water System Fall fertilization is best because the lawn has passed through the stressful summer months and needs to rebuild itself. Fall Lawn Care Guide ...
Melrose, Miss
Physiological traits contributed to the recent increase in yield potential of winter wheat from Henan Province, China.
This experiment aims to test the traits responsible for the increase in yield potential of winter wheat released in Henan Province, China. Seven established cultivars released in the last 20 years and three advanced lines were assayed. The results showed that grain yield was positively correlated with harvest index (HI), kernel number per square meter, and aboveground biomass. In addition, the HI and aboveground biomass showed an increasing trend with the year of release. Therefore, we can conclude that bread wheat breeding advances during recent decades in Henan Province, China, have been achieved through an increase in HI, kernel number per square meter, and aboveground biomass. A higher ?(13) C seems also to be involved in these advances, which suggests a progressive improvement in constitutive water use efficiency not associated with a trend towards lower stomatal conductance in the most recent genotypes. However, genetic advance does not appear related to changes in photosynthesis rates on area basis when measured in the flag leaf or the spike, but only to a higher, whole-spike photosynthesis. Results also indirectly support the concept that under potential yield conditions, the spike contributed more than the flag leaf to kernel formation. PMID:24373600
Zhou, Bangwei; Sanz-S�ez, Alvaro; Elazab, Abdelhalim; Shen, Tianmin; S�nchez-Bragado, Rut; Bort, Jordi; Serret, Maria Dolors; Araus, Jos� Luis
Winter sports are played in cold conditions on ice or snow and often at moderate to high altitude. The most important nutritional challenges for winter sport athletes exposed to environmental extremes include increased energy expenditure, accelerated muscle and liver glycogen utilization, exacerbated fluid loss, and increased iron turnover. Winter sports, however, vary greatly regarding their nutritional requirements due to variable
Nanna L. Meyer; Melinda M. Manore; Christine Helle
Coupled Model Simulation of Snowfall Events over the Black Hills.
NASA Astrophysics Data System (ADS)
Numerical simulations of two snowfall events over the Black Hills of South Dakota are made to demonstrate the use and potential of a coupled atmospheric and land surface model. The Coupled Atmospheric-Hydrologic Model System was used to simulate a moderate topographic snowfall event of 10-11 April 1999 and a blizzard event of 18-23 April 2000. These two cases were chosen to provide a contrast of snowfall amounts, locations, and storm dynamics. The model configuration utilized a nested grid with an outer grid of 16-km spacing driven by numerical forecast model data and an inner grid of 4 km centered over the Black Hills region. Simulations for the first case were made with the atmospheric model, the Advanced Regional Prediction System (ARPS) alone, and with ARPS coupled with the National Center for Atmospheric Research Land Surface Model (LSM). Results indicated that the main features of the precipitation pattern were captured by ARPS alone. However, precipitation amounts were greatly overpredicted. ARPS coupled with LSM produced a very similar precipitation pattern, but with precipitation amounts much closer to those observed. The coupled model also permits simulation of the resulting snow cover and snowmelt. Simulated percentage snow melting occurred somewhat more rapidly than that of the observed. Snow-rain discrimination may be taken from the precipitation type falling out of the atmospheric model based on the microphysical parameterization, or by the use of a surface temperature criteria, as used in most large-scale models. The resulting snow accumulation patterns and amounts were nearly identical. The coupled model configuration was used to simulate the second case. In this case the simulated precipitation and snow depth maximum over the eastern Black Hills were biased to the east and north by about 24 km. The resulting spatial correlation of the simulated snowfall and observations was only 0.37. If this bias is removed, the shifted pattern over the Black Hills region has a correlation of 0.68. Snow-melting patterns for 21 and 22 April appeared reasonable, given the spatial bias in the snowfall simulation.
Wang, J.; Hjelmfelt, M. R.; Capehart, W. J.; Farley, R. D.
NSDL National Science Digital Library
This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Form groups of three. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper. 1. In general, when are winds formed? 2. When winds are blowing, how can you get them to stop? 3. Does increased humidity usually increase of decrease your chances for rain? 4. What happens when there is ...
Millipedes and earthworms increase the decomposition rate of 15N-labelled winter rape litter in an arable field.
Effects of millipedes and earthworms on the decomposition of 15N-labelled litter of winter oilseed rape were investigated in a microcosm field experiment over a period of 264 days on an oat field near G�ttingen managed by integrated farming. A total of 32 microcosms were filled with defaunated soil. 15N-labelled rape litter was placed either on top of the soil or buried into the soil simulating mulching and ploughing, respectively. To the microcosms nine adult individuals of Blaniulus guttulatus (Diplopoda) and two of Aporrectodea caliginosa (Lumbricidae) were added separately or in combination. In general, the presence of the animals accelerated the decomposition rate of the litter material. The effects were most pronounced in the presence of Aporrectodea caliginosa. The total amount of nitrate, ammonium and the amount of 35N leached from the microcosms was increased in the presence of earthworms or of both earthworms and millipedes. Both species proved to be important members of the detritus food web of the agricultural system studied. PMID:11558655
Martens, H; Alphei, J; Schaefer, M; Scheu, S
Are the Two Most Recent Harsh Northern Hemisphere Winters Manifestation of Anthropogenic Global Warming in the Arctic?
NASA Astrophysics Data System (ADS)
The global climate models predict that temperatures will warm the greatest in winter due to a positive feedback of increased greenhouse gases (GHGs) and a diminished and darker cryosphere. However, headlines on the two most recent years have been less about the extreme warmth and more about the severity of winter weather and record snowfalls. What dynamic forcings could contribute to reversing the radiative warming forced by both increased GHGs and decreased planetary albedo resultant of a shrinking cryopshere? Furthermore, current consensus on global climate change predicts warming trends over the NH continents during boreal winter. However, recent trends in Northern Hemisphere (NH) seasonal surface temperatures diverge from these projections. For the last two decades, NH landmasses have experienced significant warming trends for all seasons except winter, when large-scale cooling trends exist instead. The surface temperature trend pattern is most closely associated with the negative polarity of the Northern Annular Mode (NAM), which has been linked with leading stratospheric circulation anomalies. These circulation anomalies are, in turn, linked with increasing Eurasian snow cover in the fall; an observed increasing trend in Eurasian snow cover, in part forced by a warming Arctic is the most likely boundary condition for partially forcing winter hemispheric trends over the past two decades that has heretofore been identified. We will also compare the trend analysis with the NAM to trend analysis with varying sea surface temperatures associated with El Nino/Southern Oscillation, the Pacific Decadal Oscillation, the Atlantic Multidecadal Oscillation, solar variability and diminishing Arctic sea ice.
Cohen, J. L.; Furtado, J. C.; Barlow, M. A.; Alexeev, V. A.; Cherry, J. E.
Winter 2009/10: A case study of an extreme Arctic Oscillation event and a skillful climate prediction
NASA Astrophysics Data System (ADS)
Winter 2009/10 made headlines for extreme cold and snow in most of the major population centers of the industrialized countries of the Northern Hemisphere (NH). The major teleconnection patterns of the Northern Hemisphere, El Ni�o/Southern Oscillation (ENSO) and the Arctic Oscillation (AO) were of moderate to strong amplitude, making both potentially key players during the winter of 2009/10. The dominant NH winter circulation pattern can be shown to have originated with a two-way stratosphere-troposphere interaction forced by Eurasian land surface and lower tropospheric atmospheric conditions during autumn. This cycle occurred twice in relatively quick succession contributing to the record low values of the AO observed. Using a skillful winter temperature forecast, it is shown that the AO explained a greater variance of the observed temperature pattern across the extratropical landmasses of the NH than did ENSO. Further, and somewhat counter-intuitively, the severe cold winter weather may be attributed to boundary forcing changes consistent with an overall warming planet. A warmer atmosphere can hold more moisture and as the interior of the NH continents cool in fall, this can lead to increased snowfall. More extensive fall snow cover contributed to the extreme negative AO observed during the winter of 2009/10.
Cohen, J. L.; Foster, J. L.; Barlow, M. A.; Saito, K.; Jones, J.
NSDL National Science Digital Library
This data tip from Bridge, the Ocean Sciences Education Teacher Resource Center archive, includes a variety of educational sites to visit, and a data exercise on snowfall patterns using local data or historical data for Salt Lake City, Utah. Learners can also discover some of the water chemistry behind snow. The activity introduces the meteogram, a time cross-section of data for a specific surface reporting station. The data plotted include temperatures, winds, pressure, clouds and present weather.
Chemical composition of fresh snowfalls at Palmer Station, Antarctica
NASA Astrophysics Data System (ADS)
A first time investigation was performed to establish a chemical baseline for snowfall at Palmer Station Antarctica (64�46'S, 64�05'W) since there was no such record. A chemical baseline for snow could be use to validate climate change studies based on ice core analyses. The snow samples contained (from high to low mass concentration) total organic carbon, chloride, inorganic carbon, sodium, sulfate, magnesium, calcium, potassium, fluoride, ammonium, and nitrate, excluding hydrogen and hydroxide. The pH of these samples ranged between 4.0-6.2. The relatively low nitrate and relatively high sulfate concentrations found in our samples are consistent with the results of other studies for this region of Antarctica. The ions and pH do not appear to favor a particular wind direction during this period. The total deposition of sulfate and flouride via snowfall between 10 January and 10 February is conservatively estimated to be 4.78 and 1.3 kg km -2, respectively.
DeFelice, T. P.
Double Fence Intercomparison Reference (DFIR) vs. Bush Gauge for "true" snowfall measurement
NASA Astrophysics Data System (ADS)
Bush Gauge measures 20-50% more snowfall than DFIR for wind speeds of 6-7 m/s.DFIR measurements need corrections for wind-induced undercatch of snowfall.Past WMO study underestimated DFIR catch, impacting national gauge assessment.
Yang, Daqing
The social impact of the snowfall of 8 March 2010 in Catalonia
NASA Astrophysics Data System (ADS)
The snowfall of 8 March 2010 affected almost all Catalonia, but especially the northeast where snow thickness was between 20 and 30 cm, locally with higher values up to 60 cm. Strong winds followed the event, exceeding 90 km/h in some places. As a result, infrastructures and public services, also private properties were damaged. Thousands of people were left stranded by the circulatory collapse, suspensions of railway service and by falling branches or trees on road infrastructures blocking accesses to residential areas. The regional government approved funds of 21.4 millions of Euros to mitigate the damage caused by this event, mainly invested in forest cleanup operations and in repairing road damage. The social impact of this event has been so high that 210 news have been published in a newspaper until 23 April, 190 of them during the month of March. From the study of the characteristics of this episode it can be stated that in the coast and pre-costal area, temperature at the same moment of precipitation was between 0�C and 2�C and humidity was high. In these zones, the type of precipitation was wet snow. It has to be considered that the combination of wet snow and wind can be a risk because of the ice-weight accumulated on objects (trees, electricity pylons...). As a consequence important damage happened in power network with significant collateral effects and more than 450,000 customers were affected by a power outage during some days. In this study we will compare the consequences of this event with others by means of information published in press. As a result, some set of consequences that are repeated regardless of the magnitude of the phenomenon will be identified. Finally, this event is also an example of the incision of social networks. This snowfall has been classified by mass media as the first "snowfall 2.0": 81600 entrances in Google, 132 Facebook groups and 750 videos made by amateurs in internet. From this study, we will present some reflexions that could be useful to improve the snow emergency plan in Catalonia, released in 2004, and mitigating the effects of future snow storms. A campaign focused on motivate population in order to increase more social commitment in these events, seems to be necessary to prevent avoidable risks. Information campaigns and some educational tasks have to be carried out to make warnings and forecasts reports clearer to citizens and to increase population sensitivity in emergency situations.
Amaro, J.; Llasat, M. C.; Aran, M.
Stable carbon isotopic ratios and ionic composition of the high-Arctic aerosols: An increase in ? 13 C values from winter to spring
values of aerosol total carbon (TC) were observed to increase from winter (? 25.7 � 0.7%) to spring (? 23.7 � 0.8%). A strong correlation (r2 = 0.92, p < 0.001) was found between the d13C values and Na+\\/TC ratios. The increased d13C values were most likely explained by an enhanced sea-to-air emission of marine organic matter to the high
M. Narukawa; K. Kawamura; S.-M. Li; J. W. Bottenheim
A Proposed Mechanism of Snowstorm Mesojet over Japan under the Influence of the Winter Monsoon.
National Technical Information Service (NTIS)
While Tsuchiya and Fujita (1966) were investigating mesoscale features of winter monsoon clouds over Japan by using satellite photographs and radiation data, a mesoscale upper-air disturbance was found to exist over the region of monsoon snowfall on the w...
T. Fujita K. Tsuchiya
Clover cover crops under-sown in winter wheat increase yield of subsequent spring barley�Effect of N dose and companion grass
Four two-year field trials, arranged in randomised split-plots, were carried out in southern Sweden with the aim of determining whether reduced N fertiliser dose in winter wheat production with spring under-sown clover cover crops, with or without perennial ryegrass in the seed mixture, would increase the clover biomass and hence the benefits of the cover crops in terms of the
G�ran Bergkvist; Maria Stenberg; Johanna Wetterlind; Birgitta B�th; Sara Elfstrand
Quiet sunrise E region: Enhancements at high latitudes in winter due to increased nitric oxide. (Reannouncement with new availability information)
E region electron concentrations derived from European Incoherent Scatter Facility observations at 70 deg N were found to be much larger than normal for high solar zenith angles during 23 of 32 days in winter. Electron concentrations computed with the Keneshea code are compatible with the observations if nitric oxide concentrations are about 10 to the 9th power/cu cm at 100 to 110 km. For these altitudes near ground sunrise, it is shown that numerically, the nitric oxide concentration approximately equals the square of the electron concentration.
Snider, W.; Keneshea, T.J.
Modeling changes in extreme snowfall events in the Central Rocky Mountains Region with the Fully-Coupled WRF-Hydro Modeling System
NASA Astrophysics Data System (ADS)
Modeling of extreme weather events often require very finely resolved treatment of atmospheric circulation structures in order to produce and localize large magnitudes of moisture fluxes that result in extreme precipitation. This is particularly true for cool season orographic precipitation processes where the representation of landform can significantly influence vertical velocity profiles and cloud moisture entrainment rates. In this work we report on recent progress in high resolution regional climate modeling of the Colorado Headwaters region using an updated version of the Weather Research and Forecasting (WRF) model and a hydrological extension package called WRF-Hydro. Previous work has shown that the WRF-Hydro modeling system forced by high resolution WRF model output can produce credible depictions of winter orographic precipitation and resultant monthly and annual river flows. Here we present results from a detailed study of an extreme springtime snowfall event that occurred along the Colorado Front Range in March of 2003. First an analysis of the simulated streamflows resulting from the melt out of that event are presented followed by an analysis of projected streamflows from the event where the atmospheric forcing in the WRF model is perturbed using the Psuedo-Global-Warming (PGW) perturbation methodology. Results from the impact of warming on total precipitation, snow-rain partitioning and surface hydrological fluxes (evapotranspiration and runoff) will be discussed in the context of how potential changes in temperature impact the amount of precipitation, the phase of precipitation (rain vs. snow) and the timing and amplitude of streamflow responses. It is shown that under the assumptions of the PGW method, intense precipitation rates increase during the event and, more importantly, that more precipitation falls as rain versus snow which significantly amplifies the runoff response from one where runoff is produced gradually to where runoff is more rapidly translated into streamflow values that approach significant flooding risks.
gochis, David; rasmussen, Roy; Yu, Wei; Ikeda, Kyoko
Reversible cerebral vasoconstriction syndrome with increased intracranial pressure, probably related to altitude changes and windy winter travelling.
Reversible cerebral vasoconstriction syndrome (RCVS) has reversible multifocal narrowing of the cerebral arteries. Respiratory alkalosis in high altitude studies cause impairment of the central nervous system, presumably by cerebral vasoconstriction. A 54 year-old woman presented with a 1-week of throbbing headache around her forehead while travelling in moderately high altitude, during a windy winter. Sudden severe headache had progressed and developed bilateral lower visual fields defect along with mild weakness of her right leg on the next day. Magnetic resonance (MR) imaging revealed acute ischemic process at both occipital, parasagittal left parietal and right frontal area. MR venography was negative but MR angiography showed multifocal narrowing of both anterior and posterior circulations. Lumbar puncture revealed the opening pressure of 240 mmH2O but normal CSF profiles. Blood tests, including complete blood count, protein C, protein S, antithrombin III, high-sensitivity C-reactive protein, immunologic and antibody profiles were normal. Dexamethasone and low-molecular weight heparin were given because the intracranial vasculitis and cerebral venous thrombosis could not be ruled out. Visual fields and right leg problems had fully recovered on the second day and second week respectively. Prednisolone was discontinued at the fourth week. MR imaging and MR angiography were repeated in the sixteenth week and revealed old infarction at the left posterior parietal area but narrowing segment of arterial systems were no longer seen. There were a few previous reported cases of RCVS in Asian counties. The authors proposed that altitude changes from travelling to the moderately high altitude and cold windy winter weather were the predisposing factors for the attack of RCVS. PMID:21675454
Tienviboon, Chaitawat; Punyagupta, Sompone; Pongtarakulpanit, Anon; Prichanond, Surawut
NSDL National Science Digital Library
This site offers general background about winter storms as well as interactive activities to teach visitors about these storms. It also offers a teacher's guide to using this site and links to other weather-related pages. There are four main topics: All About Winter Storms, Interactive Weather Maker, Interactive Winter Storm Timeline, and Ask Our Winter Storm Expert. All About Winter Storms gives general background information an a glossary of weather terms. The Weather Maker offers students a chance to control the weather through a simulation in which they affect the weather by changing variables such as humidity, equatorward temperature, and polarward temperature. The Storm Timeline offers students a chance to move up and down the timeline to learn about past winter storms. In Ask the Expert, students can email their questions to a winter storm expert and have them answered. This section also gives a brief biography of the expert.
Why does Rhinopithecus bieti prefer the highest elevation range in winter? A test of the sunshine hypothesis.
Environmental factors that affect spatiotemporal distribution patterns of animals usually include resource availability, temperature, and the risk of predation. However, they do not explain the counterintuitive preference of high elevation range in winter by the black-and-white snub-nosed monkey (Rhinopithecus bieti). We asked whether variation of sunshine along with elevations is the key driving force. To test this hypothesis, we conducted field surveys to demonstrate that there was a statistically significant pattern of high elevation use during winter. We then asked whether this pattern can be explained by certain environmental factors, namely temperature, sunshine duration and solar radiation. Finally, we concluded with a possible ecological mechanism for this pattern. In this study, we employed GIS technology to quantify solar radiation and sunshine duration across the monkey's range. Our results showed that: 1) R. bieti used the high altitude range between 4100-4400 m in winter although the yearly home range spanned from 3500-4500 m; 2) both solar radiation and sunshine duration increased with elevation while temperature decreased with elevation; 3) within the winter range, the use of range was significantly correlated with solar radiation and sunshine duration; 4) monkeys moved to the areas with high solar radiation and duration following a snowfall, where the snow melts faster and food is exposed earlier. We concluded that sunshine was the main factor that influences selection of high elevation habitat for R. bieti in winter. Since some other endotherms in the area exhibit similar winter distributional patterns, we developed a sunshine hypothesis to explain this phenomenon. In addition, our work also represented a new method of integrating GIS models into traditional field ecology research to study spatiotemporal distribution pattern of wildlife. We suggest that further theoretical and empirical studies are necessary for better understanding of sunshine influence on wildlife range use. PMID:21915329
Quan, Rui-Chang; Ren, Guopeng; Behm, Jocelyn E; Wang, Lin; Huang, Yong; Long, Yongcheng; Zhu, Jianguo
Why Does Rhinopithecus bieti Prefer the Highest Elevation Range in Winter? A Test of the Sunshine Hypothesis
Environmental factors that affect spatiotemporal distribution patterns of animals usually include resource availability, temperature, and the risk of predation. However, they do not explain the counterintuitive preference of high elevation range in winter by the black-and-white snub-nosed monkey (Rhinopithecus bieti). We asked whether variation of sunshine along with elevations is the key driving force. To test this hypothesis, we conducted field surveys to demonstrate that there was a statistically significant pattern of high elevation use during winter. We then asked whether this pattern can be explained by certain environmental factors, namely temperature, sunshine duration and solar radiation. Finally, we concluded with a possible ecological mechanism for this pattern. In this study, we employed GIS technology to quantify solar radiation and sunshine duration across the monkey's range. Our results showed that: 1) R. bieti used the high altitude range between 4100�4400 m in winter although the yearly home range spanned from 3500�4500 m; 2) both solar radiation and sunshine duration increased with elevation while temperature decreased with elevation; 3) within the winter range, the use of range was significantly correlated with solar radiation and sunshine duration; 4) monkeys moved to the areas with high solar radiation and duration following a snowfall, where the snow melts faster and food is exposed earlier. We concluded that sunshine was the main factor that influences selection of high elevation habitat for R. bieti in winter. Since some other endotherms in the area exhibit similar winter distributional patterns, we developed a sunshine hypothesis to explain this phenomenon. In addition, our work also represented a new method of integrating GIS models into traditional field ecology research to study spatiotemporal distribution pattern of wildlife. We suggest that further theoretical and empirical studies are necessary for better understanding of sunshine influence on wildlife range use.
Behm, Jocelyn E.; Wang, Lin; Huang, Yong; Long, Yongcheng; Zhu, Jianguo
NSDL National Science Digital Library
In this lesson designed to enhance literacy skills, students learn about the varied physical and behavioral adaptations that animals rely on to help them survive changing environmental conditions, such as the arrival of winter.
Foundation, Wgbh E.
NSDL National Science Digital Library
This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Weather affects our everyday lives. Some days it's sunny and some days its not. The years weather is split up into seasons. 1. What are the four seasons? 2. What kind of weather do you see in the summer? 3. What kind of weather is unique to winter? 4. ...
Bellows, Mrs.
NSDL National Science Digital Library
This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Weather affects our everyday lives. Some days it's sunny and some days its not. The years weather is split up into seasons. 1. What are the four seasons? 2. What kind of weather do you see in the summer? 3. What kind of weather is unique to winter? 4. ...
Total Lightning Observations within Electrified Snowfall using Polarimetric Radar, LMA, and NLDN Measurements
NASA Technical Reports Server (NTRS)
Four electrified snowfall cases are examined using total lightning measurements from lightning mapping arrays (LMAs), and the National Lightning Detection Network (NLDN) from Huntsville, AL and Washington D.C. In each of these events, electrical activity was in conjunction with heavy snowfall rates, sometimes exceeding 5-8 cm hr-1. A combination of LMA, and NLDN data also indicate that many of these flashes initiated from tall communications towers and traveled over large horizontal distances. During events near Huntsville, AL, the Advanced Radar for Meteorological and Operational Research (ARMOR) C-band polarimetric radar was collecting range height indicators (RHIs) through regions of heavy snowfall. The combination of ARMOR polarimetric radar and VHF LMA observations suggested contiguous layer changes in height between sloping aggregate-dominated layers and horizontally-oriented crystals. These layers may have provided ideal conditions for the development of extensive regions of charge and resultant horizontal propagation of the lightning flashes over large distances.
Schultz, Christopher J.; Carey, Lawerence D.; Brunning, Eric C.; Blakeslee, Richard
Snow climate baseline conditions and trends in Croatia relevant to winter tourism
NASA Astrophysics Data System (ADS)
The presence of snow along a portion of the Croatian highlands has enabled the development of winter tourism that is primarily oriented toward snow-related activities. Snow is more abundant and stays on the ground longer in the mountainous district of Gorski kotar (south eastern edge of the Alps) and on Mount Velebit (Dinaric Alps), which have elevations of up to 1,600 m and are close to the Adriatic coast than over the inland hilly region of north western Croatia where the summits are not more than approximately 1,000 m high. Basic information about the snow conditions at these locations was gathered for this study, including the annual cycle and probabilities for various snow parameters at different altitudes. As requested by the Croatian Ski Association, the relation between the air temperature and the relative humidity was investigated to determine the feasibility of artificial snowmaking. The snow parameters are highly correlated to air temperature, surface air pressure and precipitation, with certain differences occurring as a result of the altitude. Since the beginning of the second half of the twentieth century, winter warming and a significant increase in the mean air pressure (more anticyclonic situations) have been detected at all sites. Winter precipitation totals decreased at medium altitudes and increased at the summit of Mount Velebit, but these trends were not significant. The frequency of precipitation days and of snowfall decreased whereas an increasing fraction of the precipitation days at high altitudes involved solid precipitation. In contrast, a decreasing fraction of the precipitation days at medium altitudes involved solid precipitation, probably because of the different warming intensities at different altitudes. The mean daily snow depth and the duration of snow cover both slightly decreased at medium altitudes whereas the snow cover duration slightly increased at the mountainous summit of Mount Velebit.
Gaji?-?apka, M.
The cloud processes of a simulated moderate snowfall event in North China
NASA Astrophysics Data System (ADS)
The understanding of the cloud processes of snowfall is essential to the artificial enhancement of snow and the numerical simulation of snowfall. The mesoscale model MM5 is used to simulate a moderate snowfall event in North China that occurred during 20-21 December 2002. Thirteen experiments are performed to test the sensitivity of the simulation to the cloud physics with different cumulus parameterization schemes and different options for the Goddard cloud microphysics parameterization schemes. It is shown that the cumulus paxameterization scheme has little to do with the simulation result. The results also show that there are only four classes of water substances, namely the cloud water, cloud ice, snow, and vapor, in the simulation of the moderate snowfall event. The analysis of the cloud microphysics budgets in the explicit experiment shows that the condensation of supersaturated vapor, the depositional growth of cloud ice, the initiation of cloud ice, the accretion of cloud ice by snow, the accretion of cloud water by snow, the deposition growth of snow, and the Bergeron process of cloud ice are the dominant cloud microphysical processes in the simulation. The accretion of cloud water by snow and the deposition growth of the snow are equally important in the development of the snow.
Lin, W. S.; Bueh, C.
Integral Role of a Diabatic Rossby Vortex in a Heavy Snowfall Event.
National Technical Information Service (NTIS)
On 24-25 February 2005, a significant East Coast cyclone deposited from 4 to nearly 12 in. (10-30 cm) of snow on parts of the northeastern United States. The heaviest snowfall and most rapid deepening of the cyclone coincided with the favorable positionin...
H. C. Davies M. T. Montgomery R. W. Moore
The Development of a Snowfall Rate Algorithm Using Satellite Passive Microwave Data
A snowfall rate (water equivalent) algorithm was developed using measurements from National Oceanic and Atmospheric Administration's (NOAA) Advanced Microwave Sounding Unit (AMSU) and European Organization for the Exploitation of METeorological SATellites' (EUMATSAT) Microwave Humidity Sounder (MHS). The algorithm includes three components: Ice Water Path (IWP) retrieval, `cloud top' height retrieval, and snowflake terminal velocity. IWP is derived using a two-stream
H. Meng; B. Yan; R. R. Ferraro
ERIC Educational Resources Information Center
Materials on 11 topics presented at a winter workshop for Quebec outdoor educators have been compiled into this booklet. Action story, instant replay, shoe factory, sound and action, and find an object to fit the description are described and recommended as group dynamic activities. Directions for five games (Superlative Selection; Data�
Council of Outdoor Educators of Quebec, Montreal.
ERIC Educational Resources Information Center
Educators may find activities for indoor and outdoor winter programs in the games of the traditional Eskimo. These games are dominated by few-step operations and low level structural organization. For the most part they are quickly organized, begun, terminated, and ready to be recommenced. All types of games can be found, including quiet ones,�
Tarbuth, Lawson, Comp.
Measuring Snowfall at Summit, Greenland Using a Bistatic X-Band Radar
NASA Astrophysics Data System (ADS)
With the current warming trend of the Earth's climate, the Greenland Ice Sheet (GIS) has been melting on its fringes and experiencing mass loss. However, the mass balance of the GIS as a whole is not well understood due to a deficiency of knowledge of the interior. Central to understanding this mass balance is precipitation, of which non-satellite derived observations over the central GIS are sparse. Here a conditional snowfall retrieval for the ground-based Precipitation Occurrence Sensor System (POSS), which is part of the Integrated Characterization of Energy, Clouds, Atmospheric state and Precipitation at Summit (ICECAPS) project in Greenland, is described. The conditional restraints for the POSS retrieval are based on qualitative ice particle habit information derived from relating periodic on-site ice crystal images to ranges of cloud base temperature derived from instantaneous lidar and interpolated radiosonde measurements. The snowfall from this habit-dependent retrieval is compared to various fixed-habit retrievals for the POSS, as well as other coinciding snowfall measurements taken at Summit by a vertical-pointing Ka-band cloud radar. Providing a broader perspective, this radar-based precipitation data is analyzed alongside weekly measurements from an accumulation forest, that includes a 10x10 grid of bamboo stakes that are used to measure the height change in the snow surface. In addition to snowfall, surface height changes include contributions from deposition, sublimation, melting, drifting, and compaction that must be accounted for. Using these three perspectives on snowfall, the annual cycle of precipitation at Summit, Greenland over the past three years is examined.
Castellani, B.; Shupe, M.
A physical model to estimate snowfall over land using AMSU-B observations
NASA Astrophysics Data System (ADS)
In this study, we present a physical model to retrieve snowfall rate over land using brightness temperature observations from NOAA's Advanced Microwave Sounder Unit-B (AMSU-B) at 89 GHz, 150 GHz, 183.3 � 1 GHz, 183.3 � 3 GHz, and 183.3 � 7 GHz. The retrieval model is applied to the New England blizzard of 5 March 2001 which deposited about 75 cm of snow over much of Vermont, New Hampshire, and northern New York. In this physical model, prior retrieval assumptions about snowflake shape, particle size distributions, environmental conditions, and optimization methodology have been updated. Here, single scattering parameters for snow particles are calculated with the discrete-dipole approximation (DDA) method instead of assuming spherical shapes. Five different snow particle models are considered. Snow particle size distributions are assumed to vary with air temperature and to follow aircraft measurements described by previous studies. Brightness temperatures at AMSU-B frequencies for the New England blizzard are calculated using these DDA calculated single scattering parameters and particle size distributions. The vertical profiles of pressure, temperature, relative humidity and hydrometeors are provided by MM5 model simulations. These profiles are treated as the a priori database in the Bayesian retrieval algorithm. In algorithm applications to the blizzard data, calculated brightness temperatures associated with selected database profiles agree with AMSU-B observations to within about �5 K at all five frequencies. Retrieved snowfall rates compare favorably with the near-concurrent National Weather Service (NWS) radar reflectivity measurements. The relationships between the NWS radar measured reflectivities Ze and retrieved snowfall rate R for a given snow particle model are derived by a histogram matching technique. All of these Ze-R relationships fall in the range of previously established Ze-R relationships for snowfall. This suggests that the current physical model developed in this study can reliably estimate the snowfall rate over land using the AMSU-B measured brightness temperatures.
Kim, Min-Jeong; Weinman, J. A.; Olson, W. S.; Chang, D.-E.; Skofronick-Jackson, G.; Wang, J. R.
Deuterium content of snow as an index to winter climate in the Sierra Nevada area
The winter of 1968-69 produced two to three times the amount of precipitation in the Sierra Nevada area, California and Nevada, as the winter of 1969-70. The deuterium content in snow cores collected at the end of each winter at the same sites, which represents the total snowfall of each interval, shows a depletion in 1968-69 of approximately 20 per mil. The higher snowfall in 1968-69 and the depletion of deuterium can be explained by an uncommonly strong westward flow of cold air over and down the western slopes of the Sierras, which interacted with an eastward flow of moist Pacific air that overrode and mixed with the cold air; this resulted in precipitation that occurred in greater than normal amounts and at a lower than normal temperature. Pluvial periods of the Pleistocene may have had the same shift in air-mass trajectory as the wet 1968-69 year. Snow cores collected in the normal 1970-71 winter have deuterium concentrations that resemble those of the normal 1969-70 winter. Small and nonsystematic differences in samples from these two normal winters are due to variations in climatic character as well as to factors inherent in the sampling sites.
Friedman, I.; Smith, G. I.
NSDL National Science Digital Library
This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Form groups of three. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper. 1. In general, when are winds formed? 2. How can you get them to stop, when they are blowing? 3. What tends happens when there is a large difference between the temperatures? 4. What happens when there ...
Liz, Miss
NSDL National Science Digital Library
This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Form groups of three. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper. 1. In general, when are winds formed? 2. When winds are blowing, how can you get them to stop? 3. What usually happens when there is a large difference between the ...
Schilling, Ashley
NSDL National Science Digital Library
This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Form groups of three. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper. 1. In general, when are winds formed? 2. When winds are blowing, how can you get them to stop? 3. What usually happens when there is a large difference between the temperatures? 4. What happens when there ...
Sappa, Mr.
NSDL National Science Digital Library
This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Form groups of three. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper. 1. In general, when are winds formed? 2. When winds are blowing, how can you get them to stop? 3. What usually happens when there is a large difference between the temperatures? ...
Smith, Miss
Future increases in Arctic precipitation linked to local evaporation and sea-ice retreat.
Precipitation changes projected for the end of the twenty-first century show an increase of more than 50 per cent in the Arctic regions. This marked increase, which is among the highest globally, has previously been attributed primarily to enhanced poleward moisture transport from lower latitudes. Here we use state-of-the-art global climate models to show that the projected increases in Arctic precipitation over the twenty-first century, which peak in late autumn and winter, are instead due mainly to strongly intensified local surface evaporation (maximum in winter), and only to a lesser degree due to enhanced moisture inflow from lower latitudes (maximum in late summer and autumn). Moreover, we show that the enhanced surface evaporation results mainly from retreating winter sea ice, signalling an amplified Arctic hydrological cycle. This demonstrates that increases in Arctic precipitation are firmly linked to Arctic warming and sea-ice decline. As a result, the Arctic mean precipitation sensitivity (4.5 per cent increase per degree of temperature warming) is much larger than the global value (1.6 to 1.9 per cent per kelvin). The associated seasonally varying increase in Arctic precipitation is likely to increase river discharge and snowfall over ice sheets (thereby affecting global sea level), and could even affect global climate through freshening of the Arctic Ocean and subsequent modulations of the Atlantic meridional overturning circulation. PMID:24805239
Bintanja, R; Selten, F M
NSDL National Science Digital Library
This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. 1. What do you already know about the weather? 2. How does the weather effect you daily? Form groups of three. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper. 1. In general, when are winds formed? 2. When winds are blowing, how can you get them to stop? 3. What ...
Peterson, Lori
Correcting basin-scale snowfall in a mountainous basin using a distributed snowmelt model and remote sensing data
NASA Astrophysics Data System (ADS)
Adequate estimation of the spatial distribution of snowfall is critical in hydrologic modeling. However, this is a well-known problem in estimating basin-scale snowfall, especially in mountainous basins with data scarcity. This study focuses on correction and estimation of this spatial distribution, which considers topographic effects within the basin. A method is proposed that optimizes an altitude-based snowfall correction factor (Cfsnow). This is done through multi-objective calibration of a spatially distributed, multilayer energy and water balance-based snowmelt model (WEB-DHM-S) with observed discharge and remotely sensed snow cover data from the Moderate Resolution Imaging Spectroradiometer (MODIS). The Shuffled Complex Evolution - University of Arizona automatic search algorithm is used to obtain the optimal value of Cfsnow for minimum cumulative error in discharge and snow cover simulations. Discharge error is quantified by Nash-Sutcliffe efficiency and relative volume deviation, and snow cover error was estimated by pixel-by-pixel analysis. The study region is the heavily snow-fed Yagisawa Basin of the Upper Tone River in northeast Japan. First, the system was applied to one snow season (2002-2003), obtaining an optimized Cfsnow of 0.0007 m-1. For validation purposes, the optimized Cfsnow was implemented to correct snowfall in 2004, 2002 and 2001. Overall, the system was effective, implying improvements in correlation of simulated vs. observed discharge and snow cover. The 4 yr mean of basin-average snowfall for the corrected spatial snowfall distribution was 1160 mm (780 mm before correction). Execution of sensitivity runs against other model input and parameters indicated that Cfsnow could be affected by uncertainty in shortwave radiation and setting of the threshold air temperature parameter. Our approach is suitable to correct snowfall and estimate its distribution in poorly-gauged basins, where elevation dependence of snowfall amount is strong.
Shrestha, M.; Wang, L.; Koike, T.; Tsutsui, H.; Xue, Y.; Hirabayashi, Y.
A Physical Model to Determine Snowfall over Land by Microwave Radiometry
NASA Technical Reports Server (NTRS)
Because microwave brightness temperatures emitted by snow covered surfaces are highly variable, snowfall above such surfaces is difficult to observe using window channels that occur at low frequencies (v less than 100 GHz). Furthermore, at frequencies v less than or equal to 37 GHz, sensitivity to liquid hydrometeors is dominant. These problems are mitigated at high frequencies (v greater than 100 GHz) where water vapor screens the surface emission and sensitivity to frozen hydrometeors is significant. However the scattering effect of snowfall in the atmosphere at those higher frequencies is also impacted by water vapor in the upper atmosphere. This work describes the methodology and results of physically-based retrievals of snow falling over land surfaces. The theory of scattering by randomly oriented dry snow particles at high microwave frequencies appears to be better described by regarding snow as a concatenation of equivalent ice spheres rather than as a sphere with the effective dielectric constant of an air-ice mixture. An equivalent sphere snow scattering model was validated against high frequency attenuation measurements. Satellite-based high frequency observations from an Advanced Microwave Sounding Unit (AMSU-B) instrument during the March 5-6, 2001 New England blizzard were used to retrieve snowfall over land. Vertical distributions of snow, temperature and relative humidity profiles were derived from the Pennsylvania State University-National Center for Atmospheric Research (PSU-NCAR) fifth-generation Mesoscale Model (MM5). Those data were applied and modified in a radiative transfer model that derived brightness temperatures consistent with the AMSU-B observations. The retrieved snowfall distribution was validated with radar reflectivity measurements obtained from the National Oceanic and Atmospheric Administration (NOAA) National Weather Service (NWS) ground-based radar network.
Skofronick-Jackson, G.; Kim, M.-J.; Weinman, J. A.; Chang, D.-E.
Winter Operations-Abrasives and Salt Brine.
National Technical Information Service (NTIS)
The primary objective of winter maintenance operations is to improve traffic safety and efficiency during winter storm periods. Abrasives and salt brines have been successfully applied to increase traction and prevent snow and ice from bonding to road sur...
G. Pesti Y. Liu
Estimating snowfall patterns using timeseries of remote sensing images within a Bayesian framework
NASA Astrophysics Data System (ADS)
Snow water equivalent (SWE) reconstruction methods have been used previously to characterize seasonal SWE accumulation using mass and energy balance models. Recognizing that the spatial signature of the seasonal SWE accumulation is an integration of a series of snowfall events, we have formulated a Bayesian SWE reconstruction which utilizes the ensemble Kalman smoother (EnKS) to combine timeseries of remote sensing estimates of snow covered area (SCA) with a land surface model (LSM) to estimate snowfall distribution. An ensemble-based snow depletion curve (SDC) is used to relate SCA and SWE. We perform a series of synthetic tests to assess how much information concerning snowfall accumulation patterns can be extracted from a timeseries of SCA measurements during the ablation season. The test is performed using vegetation and meteorologic data at the 625 km2 Colorado Rabbit Ears pass area studied during the NASA Cold Lands Processes Experiment. We perform experiments to examine sensitivity to a range of physiographic variables (e.g. vegetation cover, magnitude of SWE accumulation, and fraction of total accumulation falling during the ablation season). Sensitivity to over- and underestimation of melt flux, measurement error, and error in the sub-grid precipitation coefficient of variation used to define the LSM SDC are also investigated. Predictions are made about the accuracy of the EnKS posterior SWE estimates (and, thus, the potential usefulness of the Bayesian reconstruction) under a variety of physiographic and uncertainty scenarios.
Durand, M.; Molotch, N. P.; Margulis, S. A.
NASA Technical Reports Server (NTRS)
We summarize the changes in Titans thermal structure derived from Cassini CIRS and radio-occultation data during the transition from winter to early spring. Titan's surface, and middle atmosphere show noticeable seasonal change, whereas that in most of the troposphere is mated. This can be understood in terms of the relatively small radiative relaxation time in the middle atmosphere and much larger time scale in the troposphere. The surface exhibits seasonal change because the heat capacity in an annual skin depth is much smaller than that in the lowest scale height of the troposphere. Surface temperatures rise 1 K at raid and high latitudes in the winter northern hemisphere and cool in the southern hemisphere. Changes in in the middle atmosphere are more complicated. Temperatures in the middle stratosphere (approximately 1 mbar) increase by a few kelvin at mid northern latitudes, but those at high latitudes first increase as that region moves out of winter shadow, and then decrease. This probably results from the combined effect of increased solar heating as the suit moves higher in the sky and the decreased adiabatic warming as the sinking motions associated with the cross-equatorial meridional cell weaken. Consistent with this interpretation, the warm temperatures observed higher up at the winter polar stratopause cool significantly.
Flasar, F. Michael; Achterberg, Richard; Jennings, Donald; Schinder, Paul
A Physical Model to Estimate Snowfall over Land using AMSU-B Observations
NASA Technical Reports Server (NTRS)
In this study, we present an improved physical model to retrieve snowfall rate over land using brightness temperature observations from the National Oceanic and Atmospheric Administration's (NOAA) Advanced Microwave Sounder Unit-B (AMSU-B) at 89 GHz, 150 GHz, 183.3 +/- 1 GHz, 183.3 +/- 3 GHz, and 183.3 +/- 7 GHz. The retrieval model is applied to the New England blizzard of March 5, 2001 which deposited about 75 cm of snow over much of Vermont, New Hampshire, and northern New York. In this improved physical model, prior retrieval assumptions about snowflake shape, particle size distributions, environmental conditions, and optimization methodology have been updated. Here, single scattering parameters for snow particles are calculated with the Discrete-Dipole Approximation (DDA) method instead of assuming spherical shapes. Five different snow particle models (hexagonal columns, hexagonal plates, and three different kinds of aggregates) are considered. Snow particle size distributions are assumed to vary with air temperature and to follow aircraft measurements described by previous studies. Brightness temperatures at AMSU-B frequencies for the New England blizzard are calculated using these DDA calculated single scattering parameters and particle size distributions. The vertical profiles of pressure, temperature, relative humidity and hydrometeors are provided by MM5 model simulations. These profiles are treated as the a priori data base in the Bayesian retrieval algorithm. In algorithm applications to the blizzard data, calculated brightness temperatures associated with selected database profiles agree with AMSU-B observations to within about +/- 5 K at all five frequencies. Retrieved snowfall rates compare favorably with the near-concurrent National Weather Service (NWS) radar reflectivity measurements. The relationships between the NWS radar measured reflectivities Z(sub e) and retrieved snowfall rate R for a given snow particle model are derived by a histogram matching technique. All of these Z(sub e)-R relationships fall in the range of previously established Z(sub e)-R relationships for snowfall. This suggests that the current physical model developed in this study can reliably estimate the snowfall rate over land using the AMSU-B measured brightness temperatures.
Kim, Min-Jeong; Weinman, J. A.; Olson, W. S.; Chang, D.-E.; Skofronick-Jackson, G.; Wang, J. R.
Winter range arrival and departure of white-tailed deer in northeastern Minnesota
I analyzed 364 spring and 239 fall migrations by 194 white-tailed deer (Odocoileus virginianus) from 1975 to 1993 in northeastern Minnesota to determine the proximate cause of arrivals on and departures from winter ranges. The first autumn temperatures below -7?C initiated fall migrations for 14% (95% confidence interval (CI) = 0-30) of female deer prior to snowfall in three autumns, but only 2% remained on winter ranges. During 14 autumns, the first temperatures below -7?C coincidental with snowfalls elicited migration in 45% (95% CI = 34-57) of females, and 91 % remained on winter ranges. Arrival dates failed to correlate with independent variables of temperature and snow depth, precluding predictive modeling of arrival on winter ranges. During 13 years, a mean of 80% of females permanently arrived on winter ranges by 31 December. Mean departure dates from winter ranges varied annually (19 March - 4 May) and between winter ranges (14 days) and according to snow depth (15-cm differences). Only 15 - 41 % of deer departed when snow depths were> 30 cm but 80% had done so by the time of lO-cm depths. Mean weekly snow depths in March (18-85 cm) and mean temperature in April (0.3 -8.1 ?c) explained most of the variation in mean departure dates from two winter ranges (Ely, R2 = 0.87, P < 0.0005, n = 19 springs; Isabella, R2 = 0.85, P = 0.0001, n = 12 springs). Mean differences between observed mean departure dates and mean departure dates predicted from equations ranged from 3 days (predictions within the study area) to 8 days (predictions for winter ranges 100-440 km distant).
Nelson, M.E.
The motion of mesoscale snowbands in Northeast U.S. winter storms
NASA Astrophysics Data System (ADS)
The distribution of snowfall accumulation attending winter storms is a product of both precipitation intensity and duration. Many heavy snowfall events are associated with distinct mesoscale snowbands that strongly modulate snowfall accumulation. Mesoscale snowbands are known to be favored within environments characterized by frontogenesis in the presence of weak moist symmetric or gravitational stabilities. Although the development of mesoscale snowbands often can be anticipated at 24--36-h ranges, anticipating band residence time at a fixed location remains a forecasting challenge. However, given that snowband residence time is related to characteristics of band motion, improved understanding of band motion presents an opportunity to improve snowfall accumulation forecasts. This study investigates environmental attributes associated with specific snowband motion characteristics. A classification scheme for snowband motion is developed, wherein bands are categorized into four modes: laterally translating, laterally quasi-stationary, pivoting, and hybrid. Laterally translating bands exhibit predominantly cross-axis motion, thereby favoring quasi-uniform snowfall accumulation along their paths. In contrast, laterally quasi-stationary bands are characterized by near-zero cross-axis motion, favoring heavy snowfall accumulation along a narrow corridor that may extend for several hundred kilometers. Pivoting bands exhibit pronounced rotation such that heavy snowfall accumulation is particularly favored near the center of rotation. Finally, hybrid bands are dominated by along-axis motion, but with a concurrent cross-axis component of motion. Using archived WSR-88D data, snowband events in the northeast U.S. between 2005 and 2010 have been subjectively identified and classified according to this scheme. Gridded data from the 0.5� resolution NCEP Climate Forecast System Reanalysis are used to identify environmental features associated with band motion characteristics. Results indicate that patterns of the low-to-midlevel kinematic fields, temperature advection, along- and cross-isentrope projections of the Q vector, and vertical wind shear in the near-band environment are useful in distinguishing between snowband modes. Composite fields, case studies, and conceptual models are presented to illustrate synoptic-scale features associated with different snowband motion characteristics.
Kenyon, Jaymes S.
Observed changes in extreme winter events in Europe with implication for transport system
NASA Astrophysics Data System (ADS)
Extreme weather events, such as heavy rain and snow events, storms, strong winds, low visibility, hail and extreme temperatures can have negative impact on transport sector, causing severe damages and large economic losses. Weather and climate extremes have been changed over the last few decades and are likely to continue to change in the future due to the projected climate change. Consequences of changes may be both negative and positive for transportation. Extreme winter conditions have implications for the mobility and safety of operations, leading to significant transport disruptions, increased accident risk and costs of damage. In the present study we provide a comprehensive climatology of extreme winter weather events over the European continent relevant to the transport system with primary focus on recent decades (1971-2000). Individual phenomena, such as heavy snowfall, freezing temperatures, strong winds and wind gust and also their combinations, blizzard, freezing rain are considered. The estimation of the recent and past severe events is based on the observed data available from the meteorological services, from the E-OBS dataset and the ERA40 re-analysis dataset. The analysis of the relevant hazardous weather phenomena takes into account the ranking and impact threshold values defined from the viewpoint of different transport modes, such as road, rail, aviation, waterways and light, and infrastructure. A range of statistical methods are applied to define the features of these extremes, such as their probability, changes in the spatial extension, intensity and temporal duration. In order to assess the changes in regional extremes and their effects, a European regionalization regarding similar impacts on transport network is performed. The results of extreme weather and climate events classification are also shown through a set of geographical maps.
Vajda, A.; Tuomenvirta, H.
Thresholds of Passive Microwave Snowfall Detection Determined Using A-Train Observations
NASA Astrophysics Data System (ADS)
In this study we explore a database of CloudSat+AMSU-B coincident overpasses to determine the minimum threshold of passive microwave detection of snowfall using the high-frequency channels available on GMI. Using the Advanced Infrared Sounder (AIRS) temperature and water vapor profiles along with a surface emissivity database developed from AMSU-B and MHS observations, clear-sky radiances are simulated and compared to AMSU-B observed radiances for all profiles with a maximum temperature less than 271 K. The ability of a scattering signal (observed brightness tempertaure colder than clear-sky brightness temperature by a threshold T) to detect snowfall (CloudSat reflectivity greater than threshold Z) is quantified using the Heidke Skill Score. The 183+/-1 and 183+/-3 GHz channels have the highest skill scores, while those channels that are sensitive to the surface (89, 150 and 183+/-7 GHz) have zero or even negative skill (depending on Z and T), implying that an emission signal (presumably from cloud water) is as good or better for detecting precipitation than a scattering signal. These results emphasize the need for proper characterization of surface emissivity and adequate representation of cloud water in cold season precipitation profiles that form the databases used for Bayesian retrievals from GMI and other GPM constellation radiometers.
Munchak, S. J.; Skofronick Jackson, G.; Johnson, B. T.
Can we estimate precipitation rate during snowfall using a scanning terrestrial LiDAR?
NASA Astrophysics Data System (ADS)
Accurate snowfall measurements in windy areas have proven difficult. To examine a new approach, we have installed an automatic scanning terrestrial LiDAR at Mammoth Mountain, CA. With this LiDAR, we have demonstrated effective snow depth mapping over a small study area of several hundred m2. The LiDAR also produces dense point clouds by detecting falling and blowing hydrometeors during storms. Daily counts of airborne detections from the LiDAR show excellent agreement with automated and manual snow water equivalent measurements, suggesting that LiDAR observations have the potential to directly estimate precipitation rate. Thus, we suggest LiDAR scanners offer advantages over precipitation radars, which could lead to more accurate precipitation rate estimates. For instance, uncertainties in mass-diameter and mass-fall speed relationships used in precipitation radar, combined with low reflectivity of snow in the microwave spectrum, produce errors of up to 3X in snowfall rates measured by radar. Since snow has more backscatter in the near-infrared wavelengths used by LiDAR compared to the wavelengths used by radar, and the LiDAR detects individual hydrometeors, our approach has more potential for directly estimating precipitation rate. A key uncertainty is hydrometeor mass. At our study site, we have also installed a Multi Angle Snowflake Camera (MASC) to measure size, fallspeed, and mass of individual hydrometeors. By combining simultaneous MASC and LiDAR measurements, we can estimate precipitation density and rate.
LeWinter, A. L.; Bair, E. H.; Davis, R. E.; Finnegan, D. C.; Gutmann, E. D.; Dozier, J.
Remote Measurements of Snowfalls in Wakasa Bay, Japan with Airborne Millimeter- wave Imaging Radiometer and Cloud Radar
NASA Technical Reports Server (NTRS)
In this paper we explore the application of combined millimeter-wave radar and radiometry to remotely measure snowfall. During January-February of 2003, a field campaign was conducted with the NASA P-3 aircraft in Wakasa Bay, Japan for the validation of the AMSRE microwave radiometer on board the Aqua satellite. Among the suite of instruments-on board the P-3 aircraft were the Millimeter-wave Imaging Radiometer (MIR) from the NASA Goddard Space Flight Center and the 94 GHz Airborne Cloud Radar (ACR) which is co-owned and operated by NASA Jet Propulsion Laboratory/University of Massachusetts. MIR is a total power, across-track scanning radiometer that measures radiation at the frequencies of 89, 150, 183.3 +/- 1, 183.3 +/- 3, 183.3 +/-7, 220, and 340 GHz. The MIR has flown many successful missions since its completion in May 1992. ACR is a newer instrument and flew only a few times prior to the Wakasa Bay deployment. These two instruments which are particularly well suited for the detection of snowfall functioned normally during flights over snowfall and excellent data sets were acquired. On January 14, 28, and 29 flights were conducted over snowfall events. The MIR and ACR detected strong signals during periods of snowfall over ocean and land. Results from the analysis of these concurrent data sets show that (1) the scattering of millimeter-wave radiation as detected by the MIR is strongly correlated with ACR radar reflectivity profiles, and (2) the scattering is highly frequency-dependent, the higher the frequency the stronger the scattering. Additionally, the more transparent channels of the MIR (e.g., 89, 150, and 220 GHz) are found to display ambiguous signatures of snowfall because of their exposure to surface features. Thus, the snowfall detection and retrievals of snowfall parameters, such as the ice water path (IWP) and median mass diameter (D(me)) are best conducted at the more opaque channels near 183.3 GHz and 340 GHz. Retrievals of IWP and D(me) using the MIR measurements at 183.3 and 340 GHZ are currently in progress, and the results will be compared with those derived from the ACR reflectivity profiles. Implication from this comparison will be discussed.
Wang, J. R.; Austin, R.; Liu, G. S.; Racette, P. E.
2009/2010 Eurasian Cold Winter and Loss of Arctic Sea-ice over Barents/Kara Sea
NASA Astrophysics Data System (ADS)
In 2009/2010 winter, a few extreme cold events and heavy snowfall occurred over central North America, north western Europe, and East Asia exerting a severe social and economic impacts. In this study, we performed modeling experiments to examine the role of substantially reduced Arctic sea-ice over Barents/Kara Sea on the 2009/2010 cold winters. Although several previous studies investigated cause of the extreme events and emphasized the large snow-covered area over Siberia in autumn 2009, we note that the area extent of Arctic sea-ice over Barents/Kara sea in autumn 2009 was anomalously low and the possible impact from Arctic for the extreme cold events has not been presented. To investigate the influence from the Arctic, we designed three model runs using Community Atmosphere Model Version 3 (CAM3). Each simulation differs by the prescribed surface boundary conditions: (a) CTRL - climatological seasonal cycle of sea surface temperature (SST) and sea-ice concentration (SIC) are prescribed everywhere, (b) EXP_65N - SST and SIC inside the Arctic circle (north of 65�N) are replaced by 2009/2010 values. Elsewhere, the climatology is used, (c) EXP_BK - Same with (b) except that SIC and SST are fixed only over Barents/Kara Sea where the sea-ice area dropped significantly in 2009/2010 winter. Model results from EXP_65N and EXP_BK commonly showed a large increase of air temperature in the lower troposphere where Arctic sea-ice showed a large reduction. Also, compared with the observation, model successfully captured thickened geopotential height in the Arctic and showed downstream wave propagation toward midlatitude. From the analysis, we reveal that this large dipolar Arctic-midlatitude teleconnection pattern in the upper troposphere easily propagate upward and played a role in the weakening of polar vortex. This is also confirmed in the observation. However, the timing of excitation of upward propagating wave in EXP_65N and EXP_BK were different and thus the timing of weakening of polar vortex also differs in each experiment. Unlike with our expectation, both EXP_65N and EXP_BK did not capture the abrupt increase of snow-cover in the observation over Siberian region in autumn 2009. Therefore, given the successful reproduction of key observed features of cold winter 2009/2010 by EXP_65N and EXP_BK, we conclude that Arctic sea-ice in autumn 2009 played a key role for the subsequent development of cold winter 2009/2010 and the role was largely independent with the autumn snow-cover.
Shim, T.; Kim, B.; Kim, S.
Increases in platelet and red cell counts, blood viscosity, and arterial pressure during mild surface cooling: factors in mortality from coronary and cerebral thrombosis in winter
Six hours of mild surface cooling in moving air at 24 degrees C with little fall in core temperature (0.4 degree C) increased the packed cell volume by 7% and increased the platelet count and usually the mean platelet volume to produce a 15% increase in the fraction of plasma volume occupied by platelets. Little of these increases occurred in
W R Keatinge; S R Coleshaw; F Cotter; M Mattock; M Murphy; R Chelliah
Observed snowfall and river discharge trend and low-frequency variability over Alps
NASA Astrophysics Data System (ADS)
We present a twofold analysis of long-term trend and variability of different factors affecting the hydrological cycle over the Alps in spring. The study is based on datasets derived from observations for the last 150 years. In one case we focus on snowfall flux, which we found shifting between two different regimes in concert with the Atlantic Multidecadal Oscillation. This teleconnection is explained by a mixture of changes in circulation and by local climatic feedbacks. Moreover, we analyzed the timing of the river discharge peaks relative to the main Alpine rivers, finding similar features of low frequency variability, and a common anticipation tendency of more than two weeks per century, probably explained by a change of seasonality of total precipitation.
Zampieri, Matteo; Scoccimarro, Enrico; Gualdi, Silvio
NSDL National Science Digital Library
Science of Winter is a collection of activities, lessons, interactives, images, or other content illustrating or demonstrating scientific aspects of winter weather, conditions, processes, or phenomena, appropriate for middle school, informal education, and general audiences.
Severe winter weather can lead to health and safety challenges. You may have to cope with Cold related health problems, including ... there are no guarantees of safety during winter weather emergencies, you can take actions to protect yourself. ...
ERIC Educational Resources Information Center
The article is a condensation of materials from the winter survival unit of a Canadian snow ecology course. The unit covers: cold physiology, frostbite, snowblindness, hypothermia, winter campout, and survival strategies. (SB)
Phillips, Ronald E.
Nutrition Frontiers - Winter 2010
Nutrition Frontiers - Winter 2010 Winter 2010 Volume 1, Issue 1 Dear Colleague, Welcome to the first issue of Nutrition Frontiers, a quarterly newsletter from the Nutritional Science Research Group (NSRG), Division of Cancer Prevention, NCI. In this
Efficient N Management Using Winter Oilseed Rape
\\u000a During the last decades the acreage of winter oilseed rape has been increased considerably in Europe. Rapeseed can take up\\u000a a large amount of nitrogen before winter (?>?100�kg�N???ha) and thus prevent nitrate leaching and pollution. Winter wheat\\u000a is often grown subsequently, using oilseed rape as a favorable preceding crop. However, under wheat large nitrogen losses\\u000a via leaching are frequently observed
Klaus Sieling; Henning Kage
NSDL National Science Digital Library
Cold winter weather can cause us to retreat into our indoor shells biding our time until the warmer days return. However, there is much to explore outside during the wintertime and the following sites share some important reasons and cautionary tips for Winter World Explorations. The first website, Princeton University's Outdoor Action Guide to Winter Camping by Rick Curtis, provides a thorough overview of Winter Camping including sections on Winter Travel, Snowshoeing Basics, Winter Water, and more. This site also provides links to OA Guides for Winter Shelters, and Hypothermia and Cold Injuries (1). The second site, from the Search and Rescue Society of British Columbia deals specifically with Hypothermia including useful information on Physiology, Signs, Symptoms, and Treatment Considerations (2). The third website, SnowSchool, is an innovative educational field program designed for 4th and 5th graders where "kids venture out into America's winter wildlands to discover all the living creatures under the snow." SnowSchool is a program of Winter Wildlands Alliance and "the nation's largest on-snow winter ecology education program" with 27 sites across the United States (3). The fourth website from the Minnesota DNR is a feature on Winter Bird Feeding which includes specific information about Winter Foods, Seeds and Mixes, Suet, Feeders, and Winter Feeder Layout (4). The fifth website, The Native Conifers of North America, is an excellent and very comprehensive online introduction and field guide to conifer species native to North America. The site includes A Key to the Genera and Species, sections on Selected Conifers from Different Parts of North America, and many beautiful photographs and line drawings (5). The sixth website (6) hosts an article on Winter Nutrition: Tips for people who exercise in the cold by nutrition counselor Nancy Clark, MS, RD. In her article, Ms. Clark answers common winter exercise questions like Why do I shiver when I get cold?, and Why do I feel hungrier in the winter than in the summer? Speaking of being hungrier in the winter, the final two websites offer recipes for winter stews and soups, a perfect way to end a day of winter exploring. One website offers a Hearty Winter Stew recipe from the University of Michigan Health System-Nutrition Services (7}. The other website, from The Ohio State University Extension -- Family Nutrition Program Newsletter tells us that January is National Soup Month, and offers recipes for stews, soups, and even instructions for bread soup bowls (8).
A physical model to estimate snowfall over land using microwave measurements
NASA Astrophysics Data System (ADS)
Falling snow is an important component of global precipitation in extratropical regions. This study describes the methodology and results of physically based retrievals of snow falling over land surfaces. Because microwave emitted by snow-covered surfaces are highly variable, precipitating snow above such surfaces is difficult to observe using window channels that occur at low frequencies (nu < 100 GHz). Furthermore, at frequencies nu < 37 GHz, sensitivity to liquid hydrometeors is dominant. These problems are mitigated at high frequencies (nu > 100 GHz) where water vapor screens the surface emission, and sensitivity to frozen hydrometeors is significant. However, the scattering effect of snowfall in the atmosphere at those higher frequencies is also impacted by water vapor and supercooled water in the upper atmosphere. The Discrete Dipole Approximation (DDA) method was employed to generate the single scattering parameters for nonspherical snow crystals. Comparisons show that neither equivalent spheres nor dielectric mixing theories could account for all measurements. Therefore, this study builds a look up table of the DDA calculated single scattering parameters and employs it in calculations directly. Comparisons show that DDA results calculated in this study were compatible with radar and radiometer measurements for the limited number of examples. The retrieval algorithm relied on a multi-parameter cloud model to generate the vertical structure of a snow cloud, including snow water content, snow particle effective diameter, supercooled water, and water vapor. A MM5 cloud simulation was used to provide useful statistics for generating those cloud characteristics. The snow cloud profiles and surface emissivities were then used in radiative transfer calculations that were optimized against AMSU-B observations at 89, 150, and 183.3 +/- 7, +/- 3, and +/- 1 GHz. Four variables used to adjust the snow water content, relative humidity, cloud liquid water content, and surface emissivity were sufficient to estimate snowfall rates consistent with NWS radar reflectivity measurements during the New England blizzard on March 5, 2001 and to yield a Ze-M relationship that was consistent with others reported in the literature.
Kim, Min-Jeong
Changes in natural development of shores caused by artificial disturbance, increased cyclonic activity and related warmer winters in the Sillam�e case study area (Estonia, Gulf of Finland, Baltic Sea)
NASA Astrophysics Data System (ADS)
Prior to the founding of the town of Sillam�e in 1946 when a waste depository facility was constructed across the sediment path moving along the shore on Cape P�ite, the shores nearby were one litho dynamic system with good natural balance. The shores there today are no longer in a state of dynamic equilibrium. This study analyzes how construction along the shore, increased cyclonic activity and related warmer winters has affected Sillamae's shores and how the shores are likely to evolve in the future. One of the aims is to detect the share of each factor to the the total changes on the shores of that specific location and compare the results with the previous studies carried out in more opened shores in west Estonian Archipelago. For purposes of this study, we undertook field observations to measure changes in the rate of erosion and accumulation of shore sediment. Waste depository is conserved and its shores are well protected by now. Sillam�e harbor has been established at the same place. Our analysis of shore processes and our direct observations indicate that the shores east of the harbor are still strongly influenced by the sea and far from dynamical equilibrium. Over the last few decades, the average date by which the Gulf of Finland has gradually shifted from December to January, and the average date by which such ice begins to break-up has shifted earlier. As a result, the period during which wave action is free to impact the coast is longer. Such greater lack of ice cover is exposing the shores to more stormy winter months. Accordingly, as a result of increasing cyclonic activity the development of the shores in Sillam�e has accelerated and the areas affected by erosion are widening.
T�nisson, Hannes; Kont, Are; Rivis, Reimo; Orviku, Kaarel; Suursaar, �lo; Jaagus, Jaak
[Chemical characteristics and insoluble particulates' surface morphology of a snowfall process in the southeastern suburb of Urumqi].
In order to understand the composition and potential pollution of metal elements in precipitation in the southeastern suburb of Urumqi on February 21 to 23, 2012, soluble elements were determined by inductively coupled plasma mass spectrometry (ICP-MS); in addition, energy spectrum and morphological analysis were made for insoluble particulates. The results showed that the content of toxic heavy metals in snowfall was a little high; and the enrichment factors of Se, As and Cd were 124.65, 57.69 and 36.70, respectively, showing a typical coal pollution characteristic. The back trajectory cluster analysis suggested that the coal fly ash of snowfall mainly induced by air masses originated from the coal-fire power plant in the Southwestern sampling site. Morphology analyses conducted under an scan electron microscope demonstrated fly ash coming from coal burning process and irregular mineral are in the majority of insoluble particulates in snowfall, soot aggregates were compact, when the soot was wetted (the hygroscopic behaviour), and the morphology changed further. Insoluble particulates of the southeastern suburb of Urumqi were coal fly ash and insoluble soil minerals. PMID:24946568
Lu, Hui; Wei, Wen-Shou; Cui, Cai-Xia; He, Qing; Wang, Yao
Evaluation of the Bridger Range Winter Cloud Seeding Experiment Using Control Gages.
NASA Astrophysics Data System (ADS)
A randomized exploratory single-area cloud seeding experiment was carried out in the Bridger Range of southwestern Montana during the winters of 1969-72. Seeding was accomplished using ground-based silver iodide (AgI) generators located more than midway up the west (windward) slope of the north-south Main Ridge, thereby avoiding trapping by lower stable layers. A secondary ridge from 5 to 20 km east of the Main Ridge was the expected target. An extensive airborne plume tracing program provided strong evidence of successful targeting of the AgI seeding material, with further evidence furnished by tracking of pibals and silver-in-snow analysis.The experimental unit was 24 h beginning at local noon, a natural diurnal minimum in precipitation intensity. The response variable was daily precipitation amount as measured by a dense network of recording gages. Locally-launched rawinsondes and a thermograph atop the Main Ridge provided data for partitioning the experimental days.A post hoc statistical analysis was conducted utilizing upwind and crosswind control gage data. Results from both the Wilcoxon rank-sum test and the recently developed multiresponse permutation procedure (MRPP) strongly suggest that increased target area snowfall resulted from seeding when AgI plume temperatures were colder than approximately 9�C. Double ratios yielded estimates of 15% more seasonal target area precipitation than predicted by control gages on nonseeded days, while a target-control analysis of independent snow-course data strongly suggested seeding enhanced the seasonal snowpack by more than 15%.Consideration of plume tracing findings and AgI generator calibration results suggest that the artificial ice nuclei concentration in the seeded volume would be quite limited at temperatures warmer than approximately 9�C. This provides a plausible physical explanation for the results suggested by the statistical investigations.
Super, Arlin B.; Heimbach, James A., Jr.
NSDL National Science Digital Library
Exploring Winter Olympic Sports Let's take a look at some of the different winter olympic sports Alpine Skiing Biathalon Bobsleigh Cross country Curling Figure Skating Freestyle skiing Ice Hockey Luge Nordic Combined Short track speed skating Skeleton Ski Jumping Snowboard Speed Skating ...
Keller, Mrs.
NSDL National Science Digital Library
This webpage of winter math activities includes seasonal activities for patterns, graphing, symmetry, estimations, and glyphs. Other resources on this page include literature connections, links to more winter resources, and pictures of student work. Activities are centered on penguins, snowflakes, snowman, and gingerbread.
Kawas, Terry
ERIC Educational Resources Information Center
The purpose of this article is to describe how the Department of Art Education at the University of Lapland in Finland has developed winter art as a method of environmental and community-based art education. I will focus on the Snow Show Winter Art Education Project, a training project funded by the European Union and the State Provincial Office�
Jokela, Timo
Early Childhood: The World in Winter.
ERIC Educational Resources Information Center
Various winter activities and experiences for young children are suggested. These include a getting ready for winter walk in the fall, winter birds, winter clothing, traveling in winter, winter sky watch, and others. (JN)
McIntyre, Margaret, Ed.
Evaluating Snowfall Detectability of NASA CloudSat with NOAA/NSSL Ground Radar-Based National Multi-sensor Mosaic QPE (NMQ)
NASA Astrophysics Data System (ADS)
NASA CloudSat, carrying the first space-borne Cloud Profiling Radar (CPR), is the first satellite that provides scientific communities with global snowfall observations. The accuracy of snowfall observation and quantification at middle and high latitude area is directly correlated with the liability of satellite-based precipitation estimates. However, up-to-date there is not systematic evaluation of its snowfall detectability at regional and global scale. Validation and evaluation of CPR's capability of snowfall detection is still needed in satellite precipitation communities. The NOAA/NSSL ground radar-based National Mosaic and multi-sensor Quantitative Precipitation Estimates (QPE) (NMQ or Q2) provides the high spatiotemporal resolution (1km/5min) 2-dimensional (2D) multi-suites precipitation products as well as 3-dimensional (3D) products. Such high-resolution QPE products offer an ideal alternate to evaluate satellite-based observations and products. In this paper, the CloudSat-CPR's detectability of falling snow is systematically evaluated using NMQ-Q2 snowfall products (i.e., solid snowfall precipitation identification) over the CONUS from January 2009 to December 2012. Spatial and temporal matching is applied to obtain the most matched dataset from both observations considering their differences in spatiotemporal resolution. The evaluation results offer the insights into the performance of CPR in detecting falling snow and also demonstrate its great potential in improving the solid precipitation (snowfall) in the mid-high latitude area and high-altitude area (e.g. the Tibetan plateau). A synthetic approach of incorporating the ground-radar-based NMQ products for evaluating and integrating into spaceborne radar observations will be highly expected with the launch of Global Precipitation Measurement in 2014.
Chen, S.; Cao, Q.; Hong, Y.; Gourley, J. J.; Hu, J.
Comparing Aircraft Observations of Snowfall to Forecasts Using Single or Two Moment Bulk Water Microphysics Schemes
NASA Technical Reports Server (NTRS)
High resolution weather forecast models with explicit prediction of hydrometeor type, size distribution, and fall speed may be useful in the development of precipitation retrievals, by providing representative characteristics of frozen hydrometeors. Several single or double-moment microphysics schemes are currently available within the Weather Research and Forecasting (WRF) model, allowing for the prediction of up to three ice species. Each scheme incorporates different assumptions regarding the characteristics of their ice classes, particularly in terms of size distribution, density, and fall speed. In addition to the prediction of hydrometeor content, these schemes must accurately represent the vertical profile of water vapor to account for possible attenuation, along with the size distribution, density, and shape characteristics of ice crystals that are relevant to microwave scattering. An evaluation of a particular scheme requires the availability of field campaign measurements. The Canadian CloudSat/CALIPSO Validation Project (C3VP) obtained measurements of ice crystal shapes, size distributions, fall speeds, and precipitation during several intensive observation periods. In this study, C3VP observations obtained during the 22 January 2007 synoptic-scale snowfall event are compared against WRF model output, based upon forecasts using four single-moment and two double-moment schemes available as of version 3.1. Schemes are compared against aircraft observations by examining differences in size distribution, density, and content. In addition to direct measurements from aircraft probes, simulated precipitation can also be converted to equivalent, remotely sensed characteristics through the use of the NASA Goddard Satellite Data Simulator Unit. Outputs from high resolution forecasts are compared against radar and satellite observations emphasizing differences in assumed crystal shape and size distribution characteristics.
Molthan, Andrew L.
Total Lightning Observations within Electrified Snowfall using Polarimetric Radar LMA, and NWN Measurements
NASA Technical Reports Server (NTRS)
Tall structures play and important role in development of winter time lightning flashes.To what extent still needs to be assessed. Tower initiated flashes typically occur as banded structures pass near/overhead. Hi resolution RHI s from polarimetric radar show that the lightning has a tendency to propagate through layered structures within these snowstorms.
Schultz, Christopher J.; Bruning, Eric C.; Carey, Lawrence D.; Blakeslee, Richard J.
National Technical Information Service (NTIS)
Outdoor sporting activities in winter are becoming more popular. There is a significant threat to individuals being hurt or going out unprepared for the rigors of cold weather environment. The injuries of chilblain, trenchfoot, frostbite and hypothermia a...
M. P. Hamlet
NSDL National Science Digital Library
Different human societies across the millennia have sought to record their histories in a multitude of ways, and the Lakota people of the Northern Plains elected to record their experiences through what are known as winter counts. These winter counts are essentially histories or calendars in which events are recorded by pictures, with one picture for each year. These rather fascinating documents were used in conjunction with extensive oral histories, and as such, most of these events were widely known and recognized by a majority of the Lakota. This particular website from the National Anthropological Archives at the Smithsonian National Museum of Natural History allows visitors to view these winter counts, learn more about the Lakota, and view interviews with contemporary Lakota people about the winter counts. The site also contains an audio glossary and a number of helpful resources for educators.
NSDL National Science Digital Library
Winter Weather is an In-Depth Special Report form the National Center for Atmospheric Research. It contains articles, images, activities, video clips, and interactive graphs to inform learners about meteorology and weather in the colder seasons.
Coastal Phytoplankton Do Not Rest in Winter
The climatology and interannual variability of winter phytoplankton was analyzed at the Long Term Ecological Research Station\\u000a MareChiara (LTER-MC, Gulf of Naples, Mediterranean Sea) using data collected from 1985 to 2006. Background winter chlorophyll\\u000a values (0.2�0.5�?g chl a dm?3) were associated with the dominance of flagellates, dinoflagellates, and coccolithophores. Winter biomass increases (<5.47�?g\\u000a chl a dm?3) were often recorded until
Adriana Zingone; Laurent Dubroca; Daniele Iudicone; Francesca Margiotta; Federico Corato; Maurizio Ribera d�Alcal�; Vincenzo Saggiomo; Diana Sarno
Evaluation of DFIR and Bush Gauge Snowfall Measurements at Boreal Forest Sites in Saskatchewan/Canada and Valdai/Russia
NASA Astrophysics Data System (ADS)
Snowfall is important to cold region climate and hydrology including Canada. Large uncertainties and biases exist in gauge-measured precipitation datasets and products. These uncertainties affect important decision-making, water resources assessments, climate change analyses, and calibrations of remote sensing algorithms and land surface models. Efforts have been made at both the national and international levels to quantity the errors/biases in precipitation measurements, such as the WMO Solid Precipitation Intercomparison Experiment (WMO-SPICE). Both the DFIR (double fence intercomparison reference) and the bush shielded gauge have been used in the past as a reference measurement for solid precipitation and they both have been selected as the references for the current SPICE project. Previous analyses of the DFIR vs. the bush (manual Tretyakov) gauge data collected at the Valdai station in Russia suggest DFIR undercatch of snowfall by up to 10% for high wind conditions. A regression relationship between the 2 systems was derived and used for the last WMO gauge intercomparison. Given the importance of the DFIR as the reference for the WMO SPICE project, it is necessary to re-examine and update the DFIR and bush gauge relationship. As part of Canada's contribution to the WMO SPICE project, a test site has been set up by EC/ASTD/WSDT in the southern Canadian Boreal forest to compare the DFIR and bush gauges. This site, called the Caribou Creek, has been installed within a modified young Jack Pine forest stand - north of Prince Albert in Saskatchewan. This study compiles and analyzes recent DFIR and bush gauge data from both the Valdai and Caribou Creek sites. This presentation summarizes the results of data analyses, and evaluates the performance of both references for snowfall observations in the northern regions. The methods and results of this research will directly support the WMO SPICE project and contribute to cold region hydrology and climate change research.
Yang, D.; Smith, C.
Winter QPF Sensitivities to Snow Parameterizations and Comparisons to NASA CloudSat Observations
NASA Technical Reports Server (NTRS)
Steady increases in computing power have allowed for numerical weather prediction models to be initialized and run at high spatial resolution, permitting a transition from larger scale parameterizations of the effects of clouds and precipitation to the simulation of specific microphysical processes and hydrometeor size distributions. Although still relatively coarse in comparison to true cloud resolving models, these high resolution forecasts (on the order of 4 km or less) have demonstrated value in the prediction of severe storm mode and evolution and are being explored for use in winter weather events . Several single-moment bulk water microphysics schemes are available within the latest release of the Weather Research and Forecast (WRF) model suite, including the NASA Goddard Cumulus Ensemble, which incorporate some assumptions in the size distribution of a small number of hydrometeor classes in order to predict their evolution, advection and precipitation within the forecast domain. Although many of these schemes produce similar forecasts of events on the synoptic scale, there are often significant details regarding precipitation and cloud cover, as well as the distribution of water mass among the constituent hydrometeor classes. Unfortunately, validating data for cloud resolving model simulations are sparse. Field campaigns require in-cloud measurements of hydrometeors from aircraft in coordination with extensive and coincident ground based measurements. Radar remote sensing is utilized to detect the spatial coverage and structure of precipitation. Here, two radar systems characterize the structure of winter precipitation for comparison to equivalent features within a forecast model: a 3 GHz, Weather Surveillance Radar-1988 Doppler (WSR-88D) based in Omaha, Nebraska, and the 94 GHz NASA CloudSat Cloud Profiling Radar, a spaceborne instrument and member of the afternoon or "A-Train" of polar orbiting satellites tasked with cataloguing global cloud characteristics. Each system provides a unique perspective. The WSR-88D operates in a surveillance mode, sampling cloud volumes of Rayleigh scatterers where reflectivity is proportional to the sixth moment of the size distribution of equivalent spheres. The CloudSat radar provides enhanced sensitivity to smaller cloud ice crystals aloft, as well as consistent vertical profiles along each orbit. However, CloudSat reflectivity signatures are complicated somewhat by resonant Mie scattering effects and significant attenuation in the presence of cloud or rain water. Here, both radar systems are applied to a case of light to moderate snowfall within the warm frontal zone of a cold season, synoptic scale storm. Radars allow for an evaluation of the accuracy of a single-moment scheme in replicating precipitation structures, based on the bulk statistical properties of precipitation as suggested by reflectivity signatures.
Molthan, Andrew; Haynes, John M.; Jedlovec, Gary J.; Lapenta, William M.
A coupled atmosphere-river flow simulation in California during the 1994-1995 winter
Calculation of river flow is important for managing reservoirs and flood forecasting. In the western United States, a complex terrain which is characterized by steep slopes and narrow valleys often cause a substantial rise of river levels in a short period during heavy precipitation events. Since flood control is one of the major tasks of reservoir operation, inaccurate predictions of precipitation and river flow may cause flooding or waste of water resources. Accurate calculations of river flow need accurate liquid water input to the river system at scales of individual watersheds. Precipitation and snowmelt are the most important natural source of water for a river. Reservoir operations significantly affect river flow in the western United States. Factors such as instantaneous soil water content, vegetation cover, terrain slope and ground water table structure are also crucial for river flow calculation. There are two types of precipitation: rain and snowfall. River flow quickly responds to rainfall while snowfall does not directly affect river flow until it melts afterwards. Therefore, these two types of precipitation must be separately provided to the river flow model for correct calculation of river flows. A large portion of snowfall is accumulated at high terrain during winter months in the western United States. Accumulation of snow causes the river flow to respond to instantaneous precipitation with a certain amount of time lag. During warm springs, large amounts of snowmelt can even cause local flooding. Hence, accurate estimation of snowmelt is another important step for calculating river flows. River flows are affected many different atmospheric and land surface processes. Therefore, a well-designed numerical modeling system which includes atmospheric-surface-hydrologic processes and is coupled to large-scale atmospheric data is an important tool for predicting and diagnosing local river flows and water resources.
Kim, J.; Miller, N.L.
NSDL National Science Digital Library
Is it true that no two snowflakes are alike? What happens to mosquitoes when the mercury drops? National Geographic Channel explores the planet's most extreme season. This engaging three-minute video discusses the astronomical basis for winter, and other seasons, based on the angle of incidence of the sun's rays relative to the Northern and Southern Hemispheres, as well as the components of intense winter storms.
NSDL National Science Digital Library
This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Weather affects our everyday lives. Some days it's sunny and some days its not. The years weather is split up into seasons. 1. What are the four seasons? 2. What kind of weather do you see in the summer? 3. What kind of weather is unique to winter? 4. What ...
Haight, Jennifer
Synoptic climatological study on precipitation in the Hokuriku District of Central Japan associated with the cold air outbreak in early winter (With Comparison to that in midwinter for the 1983/1984 winter)
NASA Astrophysics Data System (ADS)
In midwinter, heavy snowfall events are often brought in the Japan Sea side of the Japan Islands by the organized convective snowfall systems in the cold air outbreak situations. However, although the air temperature around the Japan Islands is still rather higher from November to early December ("early winter"), the "wintertime pressure pattern" often appears due to the considerable development of the Siberian high already in that season. Since the seasonal cycle in East Asia shows great variety with many rapid seasonal transitions influenced by the Asian monsoon system, detailed comparison of the daily precipitation climatology and the relating atmospheric processes in the cold air outbreak situations between early winter and midwinter would give us an interesting information for comprehending the overall aspects of such seasonal cycle there. Thus the present study firstly examined the daily precipitation climatology mainly at Takada, as an example for Hokuriku District, during the early to mid- winter of 1970/71 to 2009/10. Then the detailed analyses were made for the 1983/1984 winter (one of the coldest winters during that period) based on the operational meteorological data by JMA, including the ocean buoy data in the southern part of the Japan Sea for evaluating the sensible and the latent heat fluxes from the sea (referred to as SH and LH, respectively). The total precipitation at Takada in early winter was as large as in midwinter, although it was brought mainly not as snow but as rain. Such large climatological value was mainly reflected by the precipitation in the "wintertime pressure pattern" with large contribution of the days with more than 30 mm/day. Interestingly, mean daily precipitation in the "wintertime pressure pattern" in early winter was greater than in midwinter. It is noted that such features were generally found even in the latter half of the analysis period when the warmer winter years appeared more frequently than in the former half. According to the case study for 1983/84 winter, although the "wintertime pressure pattern" appeared rather frequently already from early November, each event of that pattern tended to persist only a several days. In addition, the organization of the shallow convective clouds in the cold air outbreak situation as often found in midwinter was not clearly observed. However, strong cold air advection in early winter as in midwinter over the warm underlying sea, at least in the mature stage of each "wintertime pressure situation", seems to enable the extremely huge amount of LH and the equivalently intense SH to that in midwinter, resulting in the large daily precipitation there through the enhancement of the air mass transformation process over the Japan Sea.
Kato, Kuranoshin; Nishimura, Nanako; Haga, Yuichi
NSDL National Science Digital Library
For four days last week, the daily temperatures outside the Internet Scout Project office here in Wisconsin soared above 60 F (and on one day, above 75 F), and the lakes that surround Madison melted in one fell swoop, bringing winter to a lurching halt and restless thoughts of summer to the forefront. While such local temperature anomalies are not surprising (nor did other cities experience the same highs), in this case, they fit in with a global trend that continues to raise -- in some cases, anxious -- eyebrows. On Friday, the National Oceanic and Atmospheric Administration (NOAA) announced that this winter is the warmest on record. Surpassing recent warm winter records of 1997-1998, the winter of 1999-2000 has now clinched the somewhat dubious title of warmest winter in history. This news release comes on the coat tails of a January report from the National Academy of Sciences confirming what is already accepted among most scientists -- that global warming is real (see the January 14, 2000 Scout Report). For news and information on this warmest of winters, this week's In The News features seven sites, listed above.
Payne, Laura X.
Winter Refuge for Aedes aegypti and Ae. albopictus Mosquitoes in Hanoi during Winter
Dengue occurs throughout the year in Hanoi, Vietnam, despite winter low temperatures <10�C. During July 2010 to March 2012, we surveyed monthly for Aedes larvae and pupae in 120 houses in 8 Hanoi districts. Aedes albopictus preferred discarded containers in summer and pupal density drastically decreased in winter. Aedes aegypti preferred concrete tanks and this preference increased in winter. Even in winter, the lowest water temperature found in concrete tanks was >14�C, exceeding the developmental zero point of Ae. aegypti. Although jars, drums and concrete tanks were the dominant containers previously (1994�97) in Hanoi, currently the percentage of residences with concrete tanks was still high while jars and drums were quite low. Our study showed that concrete tanks with broken lids allowing mosquitoes access were important winter refuge for Ae. aegypti. We also indicate a concern about concrete tanks serving as foci for Ae. aegypti to expand their distribution in cooler regions.
Tsunoda, Takashi; Cuong, Tran Chi; Dong, Tran Duc; Yen, Nguyen Thi; Le, Nguyen Hoang; Phong, Tran Vu; Minakawa, Noboru
NSDL National Science Digital Library
No study of Maine weather would be complete without analysis of the year of 1816 - the year with no summer in an area from western Pennsylvania and New York, up through Quebec and across to Maine and the Canadian maritimes. In this five-unit lesson, students will investigate the causes and effects of the Fabled Maine Winter by exploring a variety of data sources. They will locate, graph, and analyze meteorological and climatological data for Portland, Maine, for more recent years to try to find one that most closely resembles the fabled Maine winter of 1816.
NSDL National Science Digital Library
This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. First think about these questions: 1. What is your favorite aspect of winter weather? 2. How does the weather effect your everyday life? Form groups of THREE. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper... 1. In general, when are winds formed? 2. When winds are blowing, how can you ...
Miller, Aubree
ERIC Educational Resources Information Center
Mammals that tolerate the winter cold and stay active all year exploit the harsh northern climate to their advantage. By simple experiments and observation you can better understand their adaptations which include furry bodies, snowshoe feet, extra blubber, light coloration, and strategically distributed food caches. (JHZ)
Wapner, Suzanne
ERIC Educational Resources Information Center
Winter, like all seasons, adds a new sense of mystery and discovery to the world of young children. It is the time when they can study snowflakes, find icicles, or observe the birds that share their yards. This article presents ideas and suggestions on how to plan a playscape. A playscape is a man-made seasonal playground for young children. It�
Keeler, Rusty
PLCO News, Winter 2001 Cancer Information Service If you have a question about cancer, call and speak with a trained specialist at NCI's Cancer Information Service (CIS). The CIS operates a nationwide toll-free telephone hotline Monday-Friday, 9:00 a.m.
PLCO News, Winter 2001 Trial Update Enrollment goal: 148,000 Total enrollment (as of November 30, 2000): 152,139 Men enrolled: 75,565 Women enrolled: 76,574 Number of people enrolled at age: 55-59 49,944 60-64 47,058
The last issue of Daedalus, Journal of the American Academy of Arts and Sciences, Winter 1988, is devoted to artificial intelligence--Al, for short. It is always interesting to know what is the official position of the intellectual establishment on intellectual matters, especially where much grant allocation is concentrated.
Joseph Agassi
ERIC Educational Resources Information Center
This Winter 2007 quarterly newsletter from the Community College League of California includes: (1) Incumbents: Some Win, Some Lose in November Trustee Elections; (2) Voters Approve $2 Billion in Bonds; (3) Photos from the "Together We Can" conference; (4) Report, Media Criticize Transfer, Completion Rates and Colleges; (5) District Leader�
Giles, Ray, Ed.
Studies of the Army Aviation V/STOL Environment. Report 6. Extreme 24-Hour Snowfalls in the United States Accumulation, Distribution, and Frequency.
National Technical Information Service (NTIS)
The report presents tables and location maps of the frequency and geographic distribution in the United States of snowfalls having a potential to damage V/STOL aircraft. 'Potentially damaging' is defined as a snow buildup of 20 lb/sq ft or more, and local...
P. Riordan
The effect of orography and sea surface temperature on the heavy snowfall for the eastern region of Korea : A case study with high resolution WRF simulation
NASA Astrophysics Data System (ADS)
An analysis of the heavy snowfall that occurred on 11-14 February 2011 in the Yeongdong region along the eastern coast of Korea is presented. Relevant characteristics based on observation and model simulations are discussed with a focus on the times of maximum snowfall in Gangneung (GN) and Daegwallyong (DG). This event was considered part of the typical snowfall pattern that frequently occurs in the Yeongdong region due to the prevailing northeasterly flow. The control simulation using the high resolution Weather Research and Forecasting (WRF) model (1km X 1km) showed reasonable performance in capturing the spatial distribution and temporal evolution of precipitation. The area of precipitation maxima appeared to propagate from the plain coastal region further into the inland mountainous region, in relation to the location of convergence zone. In addition, two sensitivity experiments, EXP1 with a smoothed topography and EXP2 with a warmer sea surface temperature (SST), were performed to investigate the effect of topography and SST on the formation of heavy snowfall. EXP1 tended to modify the precipitation distribution, while EXP2 tended to produce more precipitation over the ocean. Acknowledgements This work was supported by a grant (code No. 3100-3136-442) funded by the National Institute of Meteorological Research (NIMR), the Korea Meteorological Administration (KMA)
Jung, S.-H.; Im, E.-S.; In, S.-R.; Han, S.-O.
Winter MODIS observations of West Greenland fjord ice activity
Recent observations suggest that calving of West Greenland's outlet glaciers typically ceases during winter months. However, increasingly long iceberg calving seasons pose a risk for increased dynamic thinning of Greenland's outlet glaciers. Recent publications suggest that Jakobshavn Isbrae is one example of an outlet glacier that has recently begun to experience winter calving episodes. Records of such events are limited
R. K. Cassotto; M. A. Fahnestock; J. M. Amundson
Jet streak circulations associated with a moderate snowfall event as diagnosed from NGM model output. [Nested Grid Model
NASA Technical Reports Server (NTRS)
The existence, evolution, and interaction of vertical circulations associated with upper-level jet streaks during a moderate snowfall event are diagnosed using a nested grid model (NGM). The event itself is overviewed, and the diagnosis of transverse circulations utilizing NGM output is discussed. Focus is placed on the identification of the horizontal and vertical components of the circulation, the temporal evolution of the circulation, and the comparison of the circulation from successive model forecasts. A preliminary analysis of the model data indicates that the horizontal and vertical branches of the circulations can be diagnosed from the model output, and the horizontal and vertical components of the circulations may be identified and followed during an individual forecast cycle.
Kocin, Paul J.; Uccellini, Louis W.; Skillman, William C.; Grumm, Richard H.
Measurement of atmospheric boundary layer based on super-large-scale particle image velocimetry using natural snowfall
NASA Astrophysics Data System (ADS)
We present an implementation of super-large-scale particle image velocimetry (SLPIV) to characterize spatially the turbulent atmospheric boundary layer using natural snowfall as flow tracers. The SLPIV technique achieves a measurement area of ~22 m � 52 m, up to 56 m above the ground, with a spatial resolution of ~0.34 m. The traceability of snow particles is estimated based on their settling velocity obtained from the wall-normal component of SLPIV velocity measurements. The results are validated using coincident measurements from sonic anemometers on a meteorological tower situated in close proximity to the SLPIV sampling area. A contrast of the mean velocity and the streamwise Reynolds stress component obtained from the two techniques shows less than 3 and 12 % difference, respectively. Additionally, the turbulent energy spectra measured by SLPIV show a similar inertial subrange and trends when compared to those measured by the sonic anemometers.
Toloui, M.; Riley, S.; Hong, J.; Howard, K.; Chamorro, L. P.; Guala, M.; Tucker, J.
NASA Technical Reports Server (NTRS)
Titan's atmosphere has provided an interesting study in contrasts and similarities with Earth's. While both have N$_2$ as the dominant constituent and comparable surface pressures $\\sim1$ bar, Titan's next most abundant molecule is CH$_4$, not O$_2$, and the dissociative breakup of CH$_4$ and N$_2$ by sunlight and electron impact leads to a suite of hydrocarbons and nitriles, and ultimately the photochemical smog that enshrouds the moon. In addition, with a 15.95-day period, Titan is a slow rotator compared to Earth. While the mean zonal terrestrial winds are geostrophic, Titan's are mostly cyclostrophic, whipping around the moon in as little as 1 day. Despite the different dynamical regime, Titan's winter stratosphere exhibits several characteristics that should be familiar to terrestrial meteorologists. The cold winter pole near the 1 -mbar level is circumscribed by strong winds (up to 190 m/s) that act as a barrier to mixing with airmasses at lower latitudes. There is evidence of enhancement of several organic species over the winter pole, indicating subsidence. The adiabatic heating associated with this subsidence gives rise to a warm anomaly at the 0.01-mbar level, raising the stratopause two scale heights above its location at equatorial latitudes. Condensate ices have been detected in Titan's lower stratosphere within the winter polar vortex from infrared spectra. Although not always unambiguously identified, their spatial distribution exhibits a sharp gradient, decreasing precipitously across the vortex away from the winter pole. The interesting question of whether there is important heterogeneous chemistry occurring within the polar vortex, analogous to that occurring in the terrestrial polar stratospheric clouds in the ozone holes, has not been addressed. The breakup of Titan's winter polar vortex has not yet been observed. On Earth, the polar vortex is nonlinearly disrupted by interaction with large-amplitude planetary waves. Large-scale waves have not been identified in Titan's atmosphere, so the decay of its polar vortex may be more gradual than on Earth. Observations from an extended Cassini mission into late northern spring should provide critical data indicating whether the vortex goes away with a bang or just fades away.
Flasar, F.M.; Achterberg, R.K.; Schinder, P.J.
Lightning Protection against Winter Lightning
Winter lightning, which occurs along the Sea of Japan coast, often damages transmission lines and distribution lines with the conventional lightning protection. These lines in mountainous areas suffer extensive damage from winter lightning. It is very important to investigate the features of lightning outages in detail to improve the lightning protection measures against winter lightning, therefore observations of lightning strokes
Hitoshi Sugimoto
NASA Technical Reports Server (NTRS)
19 January 2004 This somewhat oblique Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) red wide angle view of Lyot Crater and the mesas of the Deuteronilus Mensae was acquired in January 2004 on the day after the Mars Exploration Rover, Spirit, landed in Gusev Crater on the other side of the planet. It is winter in the northern hemisphere of Mars, and winter for Lyot Crater means clouds. The brighter features in the atmosphere above the surface in this image are clouds. Lyot Crater is about 236 km (147 mi.) in diameter. The center of this image is near 48.5oN, 331.0oW, and is illuminated from the lower left.
Winter cardiovascular diseases phenomenon.
THIS PAPER REVIEW SEASONAL PATTERNS ACROSS TWELVE CARDIOVASCULAR DISEASES: Deep venous thrombosis, pulmonary embolism, aortic dissection and rupture, stroke, intracerebral hemorrhage, hypertension, heart failure, angina pectoris, myocardial infarction, sudden cardiac death, venricular arrythmia and atrial fibrillation, and discuss a possible cause of the occurrence of these diseases. There is a clear seasonal trend of cardiovascular diseases, with the highest incidence occurring during the colder winter months, which have been described in many countries. This phenomenon likely contributes to the numbers of deaths occurring in winter. The implications of this finding are important for testing the relative importance of the proposed mechanisms. Understanding the influence of season and other factors is essential when seeking to implement effective public health measures. PMID:23724401
Fares, Auda
NSDL National Science Digital Library
This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Form groups of three. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper. 1. In general, when are winds formed? 2. When winds are blowing, how can you get them to stop? What is a better indicator of moisture in the air? 4. What happens when there is low ...
NSDL National Science Digital Library
This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Form groups of three. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper. 1. What causes the wind to blow. 2. When winds are blowing, how can you get them to stop? 3. What usually happens when there is a large difference between the temperatures? 4. What happens when there ...
Jones, Cory
NSDL National Science Digital Library
This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Form groups of three. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper. 1. In general, when are winds formed? 2. When winds are blowing, how can you get them to stop? 3. What usually happens when there is a large difference between the temperatures? 4. What happens when there ...
Barbieri, Mikel
NSDL National Science Digital Library
This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Weather Maker Simulator Use the weather simulation above to answer the following questions in complete sentences on paper. 1. In general, when are winds formed? 2. When winds are blowing, how can you get them to stop? 3. What usually happens when there is a large difference between the temperatures? 4. What happens when there is high ...
Frankovic, Whitney
NSDL National Science Digital Library
This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Form groups of three. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper. 1. In general, when are winds formed? 2. When winds are blowing, how can you get them to stop? 3. What usually happens when there is a large difference between the temperatures? 4. What happens when there ...
NSDL National Science Digital Library
This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Form groups of three. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper. 1. In general, when are winds formed? 2. When winds are blowing, how can you get them to stop? 3. What usually happens when there is a large difference between the temperatures? 4. What happens when there ...
NSDL National Science Digital Library
This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Form groups of three. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper. 1. In general, when are winds formed? 2. When winds are blowing, how can you get them to stop? 3. What usually happens when there is a large difference between the temperatures? 4. What happens when there ...
NSDL National Science Digital Library
This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Form groups of three. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper. 1. In general, when are winds formed? 2. When winds are blowing, how can you get them to stop? 3. What usually happens when there is a large difference between the temperatures? 4. What happens when there ...
Butcher, Kirsten
NSDL National Science Digital Library
This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Form groups of three. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper. 1. In general, when are winds formed? 2. When winds are blowing, how can you get them to stop? 3. What usually happens when there is a large difference between the temperatures? 4. What happens when there ...
The History of Winter: A Professional Development "Teacher as Scientist" Experiential Learning Field Experience.
NASA Astrophysics Data System (ADS)
Each year since 2000, the NASA Goddard History of Winter (HOW) program has allowed teachers to develop an understanding of the consequences of one segment of the orbit of the tilted Earth in its path around the sun. Scientists from NASA, CRREL, and Michigan Tech, supported by the Whiteface Observatory, and the science program at Northwood School in Lake Placid, New York, use the weather and the stratigraphy in the ice and snow, consequences of the weather changes, as "teachers" in a team study of the winter record. Snow in the air and on the ground, ice, its crystal structure and axial orientation, and the ecosystem consequences of snow and ice constitute the weeklong content package. Teacher Professional Development Standards A, B, C, and D were the guiding principles in developing HOW with a content structure formulated as protocols to serve as inserts into lesson plans and inquiry guides. The concept of HOW within NASA is to provide understanding of the WHY? and WHAT? of satellite remote sensing. The content is appropriate ground validation in that techniques presented in protocols are identical to those used by professionals who study snow pits, evaluate features in snow metamorphism, and study thin sections of ice cores drilled in ice caps and glaciers. The HOW Teacher as scientist (TAS) model is a flexible model. HOW enables teachers who are required to use inquiry-based facilitation in the classroom to experience inquiry themselves. Teachers with little science content background as well as those with Science degrees have participated in HOW working alongside of the science team. Accommodations are made through differentiation of instruction so that each group leaves with a mastery of the content that is appropriate for the transition to presentation in the classroom. Each year builds on the previous year ensuring a time series record of the history of winter-by itself a learning experience. An offshoot of the NASA Goddard Center History of Winter (HOW) Program, the Global Snowflake Network (GSN) launched in the winter of 2006 engages an international audience including both formal and informal education groups. The goal is to provide an interactive online data resource in science and education for the characterization of snowfall and related weather systems. The Global Snowflake Network has been accepted as an education outreach proposal for the International Polar Year. Collaborations with other agencies and universities also with IPY-accepted proposals are now underway. HOW and the GSN are endorsed by the NASA Goddard Education Office and many of the Goddard Snow and Ice Team scientists. Together these programs offer a unique, sustainable, and proven outreach for the Cryosphere research program. Snowflakes are like frozen data points, their shape is a record of atmospheric conditions at the time of their formation. The shapes of snowflakes vary over the winter season, with the source of a weather system and over the course of a given snowfall. The objective of the Global Snowflake Network (GSN) is to create a global ground team of teachers, students, families, and researchers worldwide to identify snowflake types during the progress of snowfalls. The result is a unique and scientifically valid resource useful to meteorology and scientific modeling of Earth's Hydrosphere. The Global Snowflake Network (GSN), simultaneously a science program and an education program is presented as a simple, scientifically valid project that has the potential to spread the IPY message and produce a lasting resource to further scientific understanding of Earth's hydrology through the study of snow.
Gabrys, R. E.
NASA Technical Reports Server (NTRS)This somewhat oblique blue wide angle Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows the 174 km (108 mi) diameter crater, Terby, and its vicinity in December 2004. Located north of Hellas, this region can be covered with seasonal frost and ground-hugging fog, even in the afternoon, despite being north of 30oS. The subtle, wavy pattern is a manifestation of fog. Location near: 28oS, 286oW Illumination from: upper left Season: Southern Winter
Winter Hypertension: Potential mechanisms
Hypertension exhibits a winter peak and summer trough in countries both north and south of the equator. A variety of explanations have been proposed to account for the seasonal nature of hypertension. It is likely that this reflects seasonal variations in risk factors. Seasonal variations have been demonstrated in a number of risk factors may play essential roles for seasonality of hypertension such as noradrenalin, catecholamine and vasopressin, vitamin D, and serum cholesterol. However, a number of studies have also suggested a direct effect of environmental temperature and physical activity on blood pressure. This paper was design to review the available evidence on seasonal variations in hypertension and possible explanations for them.
Fares, Auda
NSDL National Science Digital Library
Every morning when he walks the dog, retired professor of natural history Peter Slater can identify as many as thirty birds by their song alone. On a walk in a Scottish town with Ari Daniel Shapiro, Slater explains what two common songsters, the chaffinch and winter wren, are singing about, and how even city dwellers can learn to �bird by ear� in their own neighborhoods, with rewarding results. Also included is a Learn More section that provides background information on the scientists recorded in the podcast, lessons, images, and cool facts.
NSDL National Science Digital Library
Goals: a. Students will be able to identify the four seasons. b. Students will be able to identify three animals (bear, goose, moose) and know their lifestyle patterns in congruence with the four seasons, especially Winter months. c. Students will develop an understanding of their environment. 2nd Grade Standard III: Students will develop an understanding of their environment Objective 2: Observe and describe weather Goal C: Describe how weather affects people and weather Lesson Objectives: a. Identify the seasons and represent each with pictures and songs. b. Observe and describe typical weather for each of ...
Cook, Mrs.
NSDL National Science Digital Library
This project explores factors that help create severe winter weather. It provides an interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Form groups of three. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper. 1. In general, when are winds formed? 2. When winds are blowing, how can you get them to stop? 3. What usually happens when there is a large difference between the temperatures? 4. What happens when there ...
Prested, Miss
Stockpiled Forage Kochia to Maintain Beef Cows During Winter
Extending grazing into the winter, as opposed to feeding of harvested forages, can increase the sustainability of ranching in the western US. This study was conducted to determine the economic value of grazing stockpiled forage kochia (Kochia prostrata (L.) Scrad.) and crested wheatgrass (Agropyron desertorum (Fisch. Ex Link) Schultes) during the fall and winter. Changes in cow body weight, body
Blair L. Waldron; Dale R. ZoBell; Kenneth C. Olson; Kevin B. Jensen; Donald L. Snyder
Measuring Transpiration to Regulate Winter Irrigation Rates
Periodic transpiration (monthly sums) in a young loblolly pine plantation between ages 3 and 6 was measured using thermal dissipation probes. Fertilization and fertilization with irrigation were better than irrigation alone in increasing transpiration of young loblolly pines during winter months, apparently because of increased leaf area in fertilized trees. Irrigation alone did not significantly increase transpiration compared with the non-fertilized and non-irrigated control plots.
Samuelson, Lisa [Auburn University
Important role for ocean warming and increased ice-shelf melt in Antarctic sea-ice expansion
NASA Astrophysics Data System (ADS)
Changes in sea ice significantly modulate climate change because of its high reflective and strong insulating nature. In contrast to Arctic sea ice, sea ice surrounding Antarctica has expanded, with record extent in 2010. This ice expansion has previously been attributed to dynamical atmospheric changes that induce atmospheric cooling. Here we show that accelerated basal melting of Antarctic ice shelves is likely to have contributed significantly to sea-ice expansion. Specifically, we present observations indicating that melt water from Antarctica's ice shelves accumulates in a cool and fresh surface layer that shields the surface ocean from the warmer deeper waters that are melting the ice shelves. Simulating these processes in a coupled climate model we find that cool and fresh surface water from ice-shelf melt indeed leads to expanding sea ice in austral autumn and winter. This powerful negative feedback counteracts Southern Hemispheric atmospheric warming. Although changes in atmospheric dynamics most likely govern regional sea-ice trends, our analyses indicate that the overall sea-ice trend is dominated by increased ice-shelf melt. We suggest that cool sea surface temperatures around Antarctica could offset projected snowfall increases in Antarctica, with implications for estimates of future sea-level rise.
Bintanja, R.; van Oldenborgh, G. J.; Drijfhout, S. S.; Wouters, B.; Katsman, C. A.
Important role for ocean warming and increased ice-shelf melt in Antarctic sea-ice expansion
NASA Astrophysics Data System (ADS)
Changes in sea ice significantly modulate climate change because of its high reflective and strong insulating nature. In contrast to Arctic sea ice, sea ice surrounding Antarctica has expanded, with record extent in 2010. This ice expansion has previously been attributed to dynamical atmospheric changes that induce atmospheric cooling. Here we show that accelerated basal melting of Antarctic ice shelves is likely to have contributed significantly to sea-ice expansion. Specifically, we present observations indicating that melt water from Antarctica's ice shelves accumulates in a cool and fresh surface layer that shields the surface ocean from the warmer deeper waters that are melting the ice shelves. Simulating these processes in a coupled climate model we find that cool and fresh surface water from ice-shelf melt indeed leads to expanding sea ice in austral autumn and winter. This powerful negative feedback counteracts Southern Hemispheric atmospheric warming. Although changes in atmospheric dynamics most likely govern regional sea-ice trends, our analyses indicate that the overall sea-ice trend is dominated by increased ice-shelf melt. We suggest that cool sea surface temperatures around Antarctica could offset projected snowfall increases in Antarctica, with implications for estimates of future sea-level rise.
Bintanja, R.; Oldenborgh, G. V.; Drijhout, S.; Wouters, B.; Katsman, C. A.
NASA Technical Reports Server (NTRS)[figure removed for brevity, see original site] Annotated Version This portion of an image acquired by the Mars Reconnaissance Orbiter's High Resolution Imaging Science Experiment camera shows the Spirit rover's winter campaign site. Spirit was parked on a slope tilted 11 degrees to the north to maximize sunlight during the southern winter season. 'Tyrone' is an area where the rover's wheels disturbed light-toned soils. Remote sensing and in-situ analyses found the light-toned soil at Tyrone to be sulfate rich and hydrated. The original picture is catalogued as PSP_001513_1655_red and was taken on Sept. 29, 2006. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. The High Resolution Imaging Science Experiment is operated by the University of Arizona, Tucson, and the instrument was built by Ball Aerospace and Technology Corp., Boulder, Colo.
Winter Climate Limits Subantarctic Low Forest Growth and Establishment
Campbell Island, an isolated island 600 km south of New Zealand mainland (52�S, 169�E) is oceanic (Conrad Index of Continentality ?=??5) with small differences between mean summer and winter temperatures. Previous work established the unexpected result that a mean annual climate warming of c. 0.6�C since the 1940's has not led to upward movement of the forest limit. Here we explore the relative importance of summer and winter climatic conditions on growth and age-class structure of the treeline forming species, Dracophyllum longifolium and Dracophyllum scoparium over the second half of the 20th century. The relationship between climate and growth and establishment were evaluated using standard dendroecological methods and local climate data from a meteorological station on the island. Growth and establishment were correlated against climate variables and further evaluated within hierarchical regression models to take into account the effect of plot level variables. Winter climatic conditions exerted a greater effect on growth and establishment than summer climatic conditions. Establishment is maximized under warm (mean winter temperatures >7 �C), dry winters (total winter precipitation <400 mm). Growth, on the other hand, is adversely affected by wide winter temperature ranges and increased rainfall. The contrasting effect of winter warmth on growth and establishment suggests that winter temperature affects growth and establishment through differing mechanisms. We propose that milder winters enhance survival of seedlings and, therefore, recruitment, but increases metabolic stress on established plants, resulting in lower growth rates. Future winter warming may therefore have complex effects on plant growth and establishment globally.
Harsch, Melanie A.; McGlone, Matt S.; Wilmshurst, Janet M.
Winter climate limits subantarctic low forest growth and establishment.
Campbell Island, an isolated island 600 km south of New Zealand mainland (52 �S, 169 �E) is oceanic (Conrad Index of Continentality ?=? -5) with small differences between mean summer and winter temperatures. Previous work established the unexpected result that a mean annual climate warming of c. 0.6 �C since the 1940's has not led to upward movement of the forest limit. Here we explore the relative importance of summer and winter climatic conditions on growth and age-class structure of the treeline forming species, Dracophyllum longifolium and Dracophyllum scoparium over the second half of the 20th century. The relationship between climate and growth and establishment were evaluated using standard dendroecological methods and local climate data from a meteorological station on the island. Growth and establishment were correlated against climate variables and further evaluated within hierarchical regression models to take into account the effect of plot level variables. Winter climatic conditions exerted a greater effect on growth and establishment than summer climatic conditions. Establishment is maximized under warm (mean winter temperatures >7 �C), dry winters (total winter precipitation <400 mm). Growth, on the other hand, is adversely affected by wide winter temperature ranges and increased rainfall. The contrasting effect of winter warmth on growth and establishment suggests that winter temperature affects growth and establishment through differing mechanisms. We propose that milder winters enhance survival of seedlings and, therefore, recruitment, but increases metabolic stress on established plants, resulting in lower growth rates. Future winter warming may therefore have complex effects on plant growth and establishment globally. PMID:24691026
Harsch, Melanie A; McGlone, Matt S; Wilmshurst, Janet M
Phenological and ecological consequences of changes in winter snowpack in the Colorado Rocky Mountains
NASA Astrophysics Data System (ADS)
The date the snowpack disappears in spring is an important seasonal event at high altitudes because it determines the beginning of the growing season, which in turn influences the phenology of plant growth and flowering, and thus the availability of these resources for animal consumers. At our study site at 2,900m in the Colorado Rocky Mountains, the Rocky Mountain Biological Laboratory, snowmelt now averages two weeks earlier than in 1975. Earlier snowmelt results from a combination of lower snowfall (38 cm less since 1975), dust storms (increasing in frequency, which reduces the snowpack albedo), and warmer spring temperatures (April minimum temperature has increased 3.1�C since 1973; 2012 April mean temperature was 3.4�C above the 38-year mean). There is also a trend of increasing annual precipitation falling as rain instead of snow. We have monitored flowering phenology and abundance for about 100 species of plants in permanent plots since 1973, and use this record to look at how the change in timing of snowmelt has affected flowering. There is significant variation among years in flowering phenology (e.g., about six weeks difference between 2011 and 2012), with a mid-season decline in flowering abundance becoming apparent as the growing season starts earlier. The date of the last hard frost has not been changing in concert with the earlier growing season, with the consequence that many species now have flower buds developed that are then damaged or killed by frost. In 2012, snowmelt date was 23 April, and frost events on 27 May (-11.7�C) and 11 June (-5.6�C) did significant damage to vegetation of some species and to flower buds of many species. For example, flower abundance of the aspen sunflower Helianthella quinquenervis was 0.002% of 2011's flowering. In the absence of seed production, the demography of some plant species is likely being affected. Some animal species are also being affected by the changes in length and temperature of winter. New species of mammals, birds, and insects have begun to reproduce and overwinter at our field site in the past decade, and hibernators have changed the phenology of emergence from hibernation. Marmots now put on much more fat before entering hibernation. Interactions among species such as pollination and seed predation have also been affected by the changes in snowpack and phenology. For example, although both migratory hummingbirds and their floral resources are changing phenology, they are not changing at the same rate, leading to mismatches in their historical synchrony; hummingbirds now arrive well after their earliest food plant has begun to flower. A similar loss of synchrony appears to be affecting bumble bees as they emerge from overwintering underground, and one of their earliest nectar sources. Seed predator flies and moths, and their parasitoids, are probably being affected by the absence of seeds from species sensitive to frost. Thus many aspects of high-altitude ecological communities are being affected by the ongoing changes in depth of winter snowpack and the timing of its melting.
Inouye, D. W.; McKinney, A. M.
NASA Technical Reports Server (NTRS)
12 March 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) red wide angle image shows late winter clouds over the 104 km (65 mi) diameter crater, Mie. Cellular clouds occur in the lower martian atmosphere, surrounding Mie Crater. Their cloudtops are at an altitude that is below the crater rim. Higher than the crater rim occurs a series of lee wave clouds, indicating air circulation moving from west/northwest (left) toward the east/southeast (right). Mie Crater is located in Utopia Planitia, not too far from the Viking 2 landing site, near 48.5 N, 220.4 W. Sunlight illuminates this January 2004 scene from the lower left.
NASA Technical Reports Server (NTRS)At least three different kinds of rocks await scientific analysis at the place where NASA's Mars Exploration Rover Spirit will likely spend several months of Martian winter. They are visible in this picture, which the panoramic camera on Spirit acquired during the rover's 809th sol, or Martian day, of exploring Mars (April 12, 2006). Paper-thin layers of light-toned, jagged-edged rocks protrude horizontally from beneath small sand drifts; a light gray rock with smooth, rounded edges sits atop the sand drifts; and several dark gray to black, angular rocks with vesicles (small holes) typical of hardened lava lie scattered across the sand. This view is an approximately true-color rendering that combines images taken through the panoramic camera's 753-nanometer, 535-nanometer, and 432-nanometer filters.
The Winter Fuels Report is intended to provide concise, timely information to the industry, the press, policymakers, consumers, analysts, and state and local governments on the following topics: distillate fuel oil net production, imports and stocks for all PADD's and product supplied on a US level; propane net product supplied on a US level; propane net production, imports and stocks for Petroleum Administration for Defense Districts (PADD) I, II, and III; natural gas supply and disposition and underground storage for the United States and consumption for all PADD's; residential and wholesale pricing data for propane and heating oil for those states participating in the joint Energy Information Administration (EIA)/State Heating Oil and Propane Program; crude oil and petroleum price comparisons for the United States and selected cities; and US total heating degree-days by city. 27 figs, 12 tabs.
Not Available
Desiccation-tolerance of Fagus crenata blume seeds from localities of different snowfall regime in central Japan
In beech (Fagus crenata Blume) forests on the Pacific Ocean side in Central Japan, snowpack depth is little and xeric conditions may prevail in winter,\\u000a in contrast to heavy snow in beech forests on the Japan Sea side. The effects of such conditions during winter on the viability\\u000a of beech seeds were studied at a beech forest on the Pacific
Emiko Maruta; Tomohiko Kamitani; Midori Okabe; Yuji Ide
Impact of warm winters on microbial growth
NASA Astrophysics Data System (ADS)
Growth of soil bacteria has an asymmetrical response to higher temperature with a gradual increase with increasing temperatures until an optimum after which a steep decline occurs. In laboratory studies it has been shown that by exposing a soil bacterial community to a temperature above the community's optimum temperature for two months, the bacterial community grows warm-adapted, and the optimum temperature of bacterial growth shifts towards higher temperatures. This result suggests a change in the intrinsic temperature dependence of bacterial growth, as temperature influenced the bacterial growth even though all other factors were kept constant. An intrinsic temperature dependence could be explained by either a change in the bacterial community composition, exchanging less tolerant bacteria towards more tolerant ones, or it could be due to adaptation within the bacteria present. No matter what the shift in temperature tolerance is due to, the shift could have ecosystem scale implications, as winters in northern Europe are getting warmer. To address the question of how microbes and plants are affected by warmer winters, a winter-warming experiment was established in a South Swedish grassland. Results suggest a positive response in microbial growth rate in plots where winter soil temperatures were around 6 �C above ambient. Both bacterial and fungal growth (leucine incorporation, and acetate into ergosterol incorporation, respectively) appeared stimulated, and there are two candidate explanations for these results. Either (i) warming directly influence microbial communities by modulating their temperature adaptation, or (ii) warming indirectly affected the microbial communities via temperature induced changes in bacterial growth conditions. The first explanation is in accordance with what has been shown in laboratory conditions (explained above), where the differences in the intrinsic temperature relationships were examined. To test this explanation the temperature relationships of the bacterial community from winter-warmed plots and plots with ambient soil temperatures were compared. No change in optimum temperature for growth could be detected, indicating that the microbial community has not been warm-adapted. This fits with what was seen also in the laboratory experiment where no changes in temperature response occurred when exposing bacteria to temperatures below 10 �C within two months. The increase in activity measured during winter should thereby be due to changes in environmental factors, which will be further investigated. One big difference between heated and control plots was that heated plots were snow free during the entire winter, while control plots were covered by a 10 cm snow cover. The plant community composition and flowering time also differed in the warmed and ambient plot.
Birgander, Johanna; Rousk, Johannes; Axel Olsson, P�l
Winter chemistry of North Slope lakes
NASA Astrophysics Data System (ADS)
Lakes are important water resources on the North Slope of Alaska. Oilfield exploration and production requires water for facility use as well as transportation. Ice road construction requires winter extraction of fresh water. Since most North Slope lakes are relatively shallow, the quantity and quality of the water remaining under the ice by the end of the winter are important environmental management issues. Currently permits are based on the presence of overwintering fish populations and their sensitivity to low oxygen. Sampling during the winter of 2004 2005 sheds light on the winter chemistry of several pumped lakes and one unpumped lake on the North Slope. Dissolved oxygen, conductivity, pH, and temperature profiles were taken along with ice thickness and water depth measurements. Water samples were extracted and analyzed for Na, Ca, K, Mg, Fe, DOC, and alkalinity in the laboratory. Lake properties, rather than pumping activities, were the best predictors of oxygen depletion, with the highest levels of dissolved oxygen maintained in the lake with the least dissolved constituents. As would be expected, specific conductance increased with depth in the lake while dissolved oxygen decreased with depth. Dissolved oxygen and specific conductance data suggested that the lakes began to refresh in May. The summarized data provides a view of North Slope lake chemistry trends, while continued studies investigate the chemical impacts of pumping North Slope lakes through continued sampling and modeling efforts.
Chambers, M. K.; White, D. M.; Lilly, M. R.; Hinzman, L. D.; Hilton, K. M.; Busey, R.
Cold thoughts on nuclear winter
The nuclear winter controversy is a notorious example of the politicization of science. Large firestorms are followed by soot-laden black rain. It is not known what fraction of the soot produced by fires is removed from the atmosphere in this manner. A simple argument suggests that the fraction may be large. It is even possible to argue that a severe nuclear winter is not self-consistent. It is often assumed that carbonaceous soot is chemically inert in the atmosphere, despite the presence of trace amounts of chemically active species. Even if the magnitude of the nuclear winter effect were known, its implications would remain controversial. Nuclear winter chillings are usually measured as drops in mean temperature. However, reduction in solar heating reduces the diurnal variation as well.
Katz, J.I.
Management of Wintering Bald Eagles.
National Technical Information Service (NTIS)
Past declines in bald eagle numbers have accentuated the need for intensive species managment. Habitat requirements for nesting eagles have been determined, and some northern forests are presently managed for bald eagles. On the winter range, habitat encr...
K. Steenhof
[Winter sports and shoulder arthroplasty].
Nowadays, a general negative evaluation of sportive activity regarding different kinds of sport following arthroplasty is at present no more scientifically supported. However, at present no valid guidelines regarding sportive activity of patients after implantation of shoulder joint arthroplasty exist. The question regarding the ability of performing winter sports activities of patients treated with shoulder joint endoprothesis has not been answered so far. Therefore the aim of the presented work was to identify winter sports-specific risks for patients treated with shoulder joint endoprothesis as well as to critically discuss the actual literature in refer to winter sport activities. Criteria for the education of patients with shoulder joint endoprothesis as well as consultation regarding winter sport activities will be provided for the orthopaedic surgeon. PMID:18814057
Kirchhoff, C; Imhoff, A B; Hinterwimmer, S
Learners in Action, Winter 2005
ERIC Educational Resources Information Center
This Winter 2005 issue of "Learners in Action" contains the following: (1) Proud Dad Turns Family Life Around (Nick Prince); (2) Learners Make a Great Impression at Conference; (3) The Story behind the Story; and (4) Learner Resources.
Movement for Canadian Literacy, 2005
National Technical Information Service (NTIS)
Deals with the dangers inherent in winter weather. Gives advice to the average citizen on how to prepare for severe weather conditions, explains the meaning of specific forecasts, and pints up the necessity for emergency planning by local governments.
The Challenge of Winter Backpacking.
ERIC Educational Resources Information Center
Tips and techniques for safe and enjoyable winter backpacking are offered. Topics covered include cross county skis, snowshoes, clothing, footwear, shelter, sleeping bags, food, hypothermia prevention, as well as general rules and requirements. (CO)
Cavanaugh, Michael; Mapes, Alan
[Ecological benefits of planting winter rapeseed in western China].
To evaluate the ecological benefits of popularizing winter rapeseed planting in western China, a wind tunnel simulation test was conducted with four kinds of farmland surface, i.e., winter rapeseed, winter wheat, wheat stubble, and bare field just after spring sowing, collected from west Gansu in April. The results showed that winter rapeseed surface had a roughness of 4.08 cm and a threshold wind velocity as high as 14 m x s(-1), being more effective in blown sand control than the other three surfaces. Under the same experimental conditions, the wind erosion modulus and sand transportation rate of winter rapeseed surface were only 4.1% and 485% of those of the bare field just after spring sowing, and the losses of soil organic matter, alkali-hydrolyzed N, available P and K, catalase, urease, alkaline phosphatase, invertase, and microbes of winter rapeseed surface due to wind erosion were only 1.4%, 5.1%, 1.6%, 2.7%, 9.7%, 3.6%, 6.3%, 6.7% and 1.5% of those of the bare field, respectively. It was suggested that popularizing winter rapeseed planting in west China could control wind erosion, retain soil water and nutrients, increase multicropping index, and improve economic benefits of farmland. In addition, it could benefit the regional desertification control and ecological environment improvement. PMID:19637605
Wang, Xue-fang; Sun, Wan-cang; Li, Fang; Kang, Yan-li; Pu, Yuan-yuan; Liu, Hong-xia; Zeng, Chao-wu; Fan, Chong-xiu
Seasonal Predictability of The Winter NAO From North Atlantic Sst
NASA Astrophysics Data System (ADS)
We quantify the seasonal predictability of the winter (December-January-February) North Atlantic Oscillation (NAO) from lagged north Atlantic sea surface tempera- tures (SSTs). We achieve this by identifying the SST lagged spatial modes whose principal components (PCs) are correlated significantly to various upcoming winter NAO indices. Using linear regression with the PCs as predictors we compute the pre- dictability and significance of the winter NAO from cross-validation for the period 1950/1-2000/1 and from simulated real time forecasts for the recent 15 year period 1986/7-2000/1. Based on data through the end of October the model anticipates the upcoming winter NAO - for a range of NAO indices - with a correlation between 0.47 and 0.63 for 1950/1-2000/1, increasing to between 0.51 and 0.65 for the 1986/7- 2000/1 simulated real-time forecast period. The model anticipates the correct NAO sign in 67% to 75% of the last 51 winters and in 80% to 93% of the last 15 winters. This skill is marginal but useable. Our findings suggest that atmospheric and coupled general circulation models are underestimating the predictability of the winter NAO from north Atlantic SSTs.
Qian, B.; Saunders, M. A.
Remote response of the East Asian winter monsoon to tropical forcing related to El Ni�o-Southern Oscillation
NASA Astrophysics Data System (ADS)
The mechanism of the East Asian winter monsoon variability in response to El Ni�o-Southern Oscillation (ENSO)-related tropical forcing is investigated using Japanese long-term reanalysis project data, additionally aided by the Japan Meteorological Agency climate data assimilation system. There are at least two different responses, zonally symmetric and asymmetric, of the Asian jet over South Asia to the ENSO-related tropical convective forcing during the Northern Hemisphere winter. The zonally symmetric response, induced by zonally extended anomalous convection from the Philippine Sea through southern India and Sri Lanka, is pronounced at the mature phase of ENSO. The zonally asymmetric response is intimately associated with anomalous convection localized in the vicinity of the Philippine and South China seas, accompanied by an anomalous Walker circulation cell between the Maritime Continent and tropical Indian Ocean. When this asymmetric response is prominent, ENSO-related anomalous convection can give rise to a change in the East Asian winter monsoon system through stationary Rossby wave propagation along the South Asian waveguide. The North Atlantic Oscillation (NAO)-related extratropical forcing is also a crucial factor and contributes not only to the downstream development of subpolar teleconnections across northern Eurasia but also to the reinforcement of the zonally asymmetric pattern of the Asian jet over South Asia, resulting in a significant effect on the East Asian winter monsoon circulation. A combination of the ENSO- and NAO-related forcing plays a vital role in triggering the occurrence of extraordinary anomalous monsoon circulations, such as extremely heavy snowfall in the 2005/2006 winter in Japan.
Sakai, Kumi; Kawamura, Ryuichi
NASA Technical Reports Server (NTRS)Approaching its 47th month of a Mars surface mission originally planned to last three months, NASA's Spirit rover was also approaching the northern edge of a low plateau called 'Home Plate.' The rover's operators selected an area with north-facing slope there as a destination where Spirit would have its best chance of surviving low-solar-energy conditions of oncoming Martian winter. The yellow line on this map of the Home Plate area indicates Spirit's route from early February 2006, entering the mapped area from the north (top), to late November 2007, on the western edge of the bright-toned Home Plate plateau. The map covers an area about 160 meters (525 feet) across from west to east. Labels indicate the area intended for Spirit to spend many months spanning the rover's third Martian winter, the site where it spent about seven months (April to November 2006) spanning its second winter, and the site where it lost use of the drive motor for one of its six wheels. A north-facing slope helps Spirit maximizes electric output from its solar panels during winter months because Spirit is in the southern hemisphere of Mars, so the sun appears only in the northern sky during winter. For the third winter, which will reach its minimum solar-energy days in early June 2008, Spirit faces the challenge of having more dust on its solar panels than it had during its second winter. The base image for this map is a portion of a color image taken on Jan. 9, 2007, by the High Resolution Imaging Science Experiment camera on NASA's Mars Reconnaissance Orbiter.
Natural snowfall reveals large-scale flow structures in the wake of a 2.5-MW wind turbine.
To improve power production and structural reliability of wind turbines, there is a pressing need to understand how turbines interact with the atmospheric boundary layer. However, experimental techniques capable of quantifying or even qualitatively visualizing the large-scale turbulent flow structures around full-scale turbines do not exist today. Here we use snowflakes from a winter snowstorm as flow tracers to obtain velocity fields downwind of a 2.5-MW wind turbine in a sampling area of ~\
Hong, Jiarong; Toloui, Mostafa; Chamorro, Leonardo P; Guala, Michele; Howard, Kevin; Riley, Sean; Tucker, James; Sotiropoulos, Fotis
Snowfall in Southern Appalachia
NASA Technical Reports Server (NTRS)The snowstorm which swept across the eastern United States on December 4 and 5 also brought the season's first snow to parts of the south and southern Appalachia. The extent of snow cover over central Kentucky, eastern Tennessee, western North Carolina and Virginia are apparent in this view from the Multi-angle Imaging SpectroRadiometer (MISR). This natural-color image was captured by MISR's downward-looking (nadir) camera on December 7, 2002.The Appalachians are bounded by the Blue Ridge mountain belt along the east and the Appalachian Plateau along the west. Valleys and ridges between the higher elevation areas retain the green and reddish-brown hues of autumn, and many rivers and lakes appear blue and unfrozen. The highest peak in the eastern United States, Mount Mitchell, is found in North Carolina's western tip, near the Great Smoky Mountains (the dark-colored range at lower right).The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously and every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude. This data product was generated from a portion of the imagery acquired during Terra orbit 15805. The image covers an area of 347 kilometers x 279 kilometers, and utilizes data from blocks 60 to 62 within World Reference System-2 path 19.
Effect of potassium rate on growth, quality, chemical composition, and winter hardiness of perennial ryegrass
Seven potassium (K) rates (0, 50, 150, 350, 450, 550, and 650 kg K\\/ha) were used to determine the optimum rate of K for turf?type perennial ryegrass during the winter based on turf growth, quality, and winter hardiness. Turf density, color, growth, and winter hardiness were increased as the rate of K application increased up to 350 kg K\\/ha. However,
Khorshid Razmjoo; Seiji Kaneko
NASA Technical Reports Server (NTRS)
Goodyear Tire and Rubber Company developed a material for Johnson Space Center used as parachute shrouds to soft land the Vikings through the tenuous Martian atmosphere and has been adapted to new radial tire five times stronger than steel. Fiber has a chain-like molecular structure that gives it incredible strength in proportion to its weight. Material is expected to increase tread life by 10,000 miles.
A comparison of winter mercury accumulation at forested and no-canopy sites measured with different snow sampling techniques
Atmospheric mercury (Hg) is delivered to ecosystems via rain, snow, cloud/fog, and dry deposition. The importance of snow, especially snow that has passed through the forest canopy (throughfall), in delivering Hg to terrestrial ecosystems has received little attention in the literature. The snowpack is a dynamic system that links atmospheric deposition and ecosystem cycling through deposition and emission of deposited Hg. To examine the magnitude of Hg delivery via snowfall, and to illuminate processes affecting Hg flux to catchments during winter (cold season), Hg in snow in no-canopy areas and under forest canopies measured with four collection methods were compared: (1) Hg in wet precipitation as measured by the Mercury Deposition Network (MDN) for the site in Acadia National Park, Maine, USA, (2) event throughfall (collected after snowfall cessation for accumulations of >8 cm), (3) season-long throughfall collected using the same apparatus for event sampling but deployed for the entire cold season, and (4) snowpack sampling. Estimates (mean ?? SE) of Hg deposition using these methods during the 91-day cold season in 2004-2005 at conifer sites showed that season-long throughfall Hg flux (1.80 ??g/m2) < snowpack Hg (2.38 ?? 0.68 ??g/m2) < event throughfall flux (5.63 ?? 0.38 ??g/m2). Mercury deposition at the MDN site (0.91 ??g/m2) was similar to that measured at other no-canopy sites in the area using the other methods, but was 3.4 times less than was measured under conifer canopies using the event sampling regime. This indicates that snow accumulated under the forest canopy received Hg from the overstory or exhibited less re-emission of Hg deposited in snow relative to open areas. The soil surface of field-scale plots were sprayed with a natural rain water sample that contained an Hg tracer (202Hg) just prior to the first snowfall to explore whether some snowpack Hg might be explained from soil emissions. The appearance of the 202Hg tracer in the snowpack (0-64% of the total Hg mass in the snowpack) suggests that movement of Hg from the soil into the snowpack is possible. However, as with any tracer study the 202Hg tracer may not precisely represent the reactivity and mobility of natural Hg in soils. ?? 2007 Elsevier Ltd. All rights reserved.
Nelson, S. J.; Johnson, K. B.; Weathers, K. C.; Loftin, C. S.; Fernandez, I. J.; Kahl, J. S.; Krabbenhoft, D. P.
Cold thoughts on nuclear winter
The nuclear winter controversy is a notorious example of the politicization of science. Large firestorms are followed by soot-laden black rain. It is not known what fraction of the soot produced by fires is removed from the atmosphere in this manner. A simple argument suggests that the fraction may be large. It is even possible to argue that a severe
Nuclear Winter: The Continuing Debate.
National Technical Information Service (NTIS)
This essay examines the debate over the climatic consequences of global nuclear war as related in the so-called Nuclear Winter hypothesis. the review examines the major components of the theory and traces development of the scientific knowledge leading to...
A. V. Nida
Learners in Action, Winter 2006
ERIC Educational Resources Information Center
This Winter 2006 issue of "Learners in Action" contains the following articles: (1) Premiers Honour Adult Learners; (2) Learning Difficulties?; (3) Awards; (4) Hats off to Jacques Demers!; (5) What Do You Think?; (6) Meet the Current Learners Advisory Network; and (7) "Learning Edge" is No Ordinary Magazine!.
Movement for Canadian Literacy, 2006
Learning through a Winter's Tale
ERIC Educational Resources Information Center
In this article, the author shares her experience during the final semester of Year 11 Theatre Studies when she performed a monologue about Hermione from "The Winter's Tale". This experience was extremely significant to her because it nearly made her lose faith in one of the most important parts of her life, drama. She believes this experience,�
Vidotto, Kristie
Unusual Southern Hemisphere Stratosphere Winter of 2002.
National Technical Information Service (NTIS)
The southern hemisphere stratospheric winter of 2002 was the most unusual winter yet observed in the southern hemisphere climate record. Temperatures near the edge of the Antarctic polar vortex were considerably warmer than normal over the entire course o...
P. A. Newman E. R. Nash
Britannica Sporting Record: The Winter Games
NSDL National Science Digital Library
Encyclopaedia Britannica's Olympic Winter Games site offers detailed Olympic information and history. Offerings include an overview of the Olympic movement, histories of each of the past seventeen Olympic Winter Games, articles about the events included in the Winter Games, biographies of past competitors, and a searchable Olympic Record database. This well-researched site provides an interesting backdrop for this year's Winter Games in Nagano, Japan.
Encyclopaedia Britannica, Inc.
Movements of wintering Dunlin Calidris alpina and changing habitat availability in an agricultural wetland landscape
Few studies have assessed how the dynamics of wetland bird movements relate to changing resource availability, particularly at more than one spatial scale. Within western Oregon's Williamette Valley, we examined winter resident Dunlin Calidris alpina movements in relation to a decrease in availability of preferred shorebird foraging habitat from early to late winter of 1999-2000. By tracking movements of 15 (early winter) and 12 (late winter) radiomarked individuals, we calculated home ranges and characterized presence/absence of a preference for shorebird foraging habitat during each winter period. Between periods, we compared: (1) percentage of shorebird habitat in home ranges to its availability in the landscape (regional preference), (2) percentage of radio locations in shorebird habitat to its availability within home ranges (local preference) and (3) relative use of roost sites. Concurrent with a 75% decrease in available shorebird habitat from early to late winter, average home range sizes increased by a factor of 3.8. At a regional scale, home ranges in early winter included a significantly greater percentage of shorebird foraging habitat than was available in the wider landscape. However, by late winter, the percent of shorebird habitat in home ranges did not match availability in the landscape. At the local scale, for both winter periods Dunlin were located in shorebird foraging habitat more often than expected given availability of habitat within home ranges [Correction added after online pub-lication 23 May 2008: sentence amended]. An increase in the number of roosts used from early to late winter implies possible reliance on additional sites in late winter for foraging opportunities. Results suggest that wet, unvegetated habitat is sought by Dunlin throughout winter, but individuals could not select home ranges in late winter that fully compensated for seasonal loss of habitat. ?? 2008 The Authors.
Taft, O. W.; Sanzenbacher, P. M.; Haig, S. M.
Leadership in American Indian Communities: Winter Lessons
ERIC Educational Resources Information Center
Winter lessons, or stories told in the winter, were one of the ways in which tribal elders instructed and directed young men and women in the proper ways to assume leadership responsibilities. Winter lessons stressed the appropriate relationship between the leader and the community. The intent was to remember the power and purpose of that�
Metoyer, Cheryl A.
33 CFR 100.109 - Winter Harbor Lobster Boat Race, Winter Harbor, ME.
Code of Federal Regulations, 2010 CFR
... 1 2010-07-01 2010-07-01 false Winter Harbor Lobster Boat Race, Winter Harbor, ME. 100.109 Section 100.109...SAFETY OF LIFE ON NAVIGABLE WATERS § 100.109 Winter Harbor Lobster Boat Race, Winter Harbor,...
33 CFR 100.109 - Winter Harbor Lobster Boat Race, Winter Harbor, ME.
Code of Federal Regulations, 2010 CFR
... 1 2009-07-01 2009-07-01 false Winter Harbor Lobster Boat Race, Winter Harbor, ME. 100.109 Section 100.109...SAFETY OF LIFE ON NAVIGABLE WATERS § 100.109 Winter Harbor Lobster Boat Race, Winter Harbor,...
Glycogen, not dehydration or lipids, limits winter survival of side-blotched lizards (Uta stansburiana).
Climate change is causing winters to become milder (less cold and shorter). Recent studies of overwintering ectotherms have suggested that warmer winters increase metabolism and decrease winter survival and subsequent fecundity. Energetic constraints (insufficient energy stores) have been hypothesized as the cause of winter mortality but have not been tested explicitly. Thus, alternative sources of mortality, such as winter dehydration, cannot be ruled out. By employing an experimental design that compared the energetics and water content of lizards that died naturally during laboratory winter with those that survived up to the same point but were then sacrificed, we attempt to distinguish among multiple possible causes of mortality. We test the hypothesis that mortality is caused by insufficient energy stores in the liver, abdominal fat bodies, tail or carcass or through excessive water loss. We found that lizards that died naturally had marginally greater mass loss, lower water content, and less liver glycogen remaining than living animals sampled at the same time. Periodically moistening air during winter reduced water loss, but this did not affect survival, calling into question dehydration as a cause of death. Rather, our results implicate energy limitations in the form of liver glycogen, but not lipids, as the primary cause of mortality in overwintering lizards. When viewed through a lens of changing climates, our results suggest that if milder winters increase the metabolic rate of overwintering ectotherms, individuals may experience greater energetic demands. Increased energy use during winter may subsequently limit individual survival and possibly even impact population persistence. PMID:22875774
Zani, Peter A; Irwin, Jason T; Rollyson, Mary E; Counihan, Jessica L; Healas, Sara D; Lloyd, Emily K; Kojanis, Lee C; Fried, Bernard; Sherma, Joseph
Scenario-based risk analysis of winter snowstorms in the German lowlands
NASA Astrophysics Data System (ADS)
The northern German lowlands are not especially known for a high frequency of snowfall events. Nevertheless under certain synoptic conditions Lake-Effect-like phenomena caused by the proximity especially of the Baltic Sea can lead to significantly reinforced snowfall intensities that are often accompanied by rather high wind speeds. This makes for infrequent but potentially disastrous snowstorms in a region less accustomed to snow impacts. One possible consequence of an infrastructure failure cascade resulting from severe and longer-lasting snowstorms is a regional disruption of the food supply chain. In the context of "just-in-time"-logistics and the accompanying decrease of storage capabilities, this poses a significant threat to the population's food security. Within the project NeuENV ("New strategies to ensure sufficient food supply in case of crisis in Germany") a snowstorm in the German lowlands involving widespread disruptions of the transportation infrastructure as well as power failures is therefore used as one model for future food supply chain disruptions. In order to obtain a reliable evaluation of the supply chain and crisis management resilience, a detailed snowstorm scenario is being developed. For this purpose, a database of impact reports of past snowstorm events is assembled and analysed to obtain a comprehensive overview of potential infrastructure impairments and failures. Examples of events analysed in this context include the winter 1978/79 with its disastrous snow drifts that commonly attained heights of 3m to 5m leading to a transportation infrastructure collapse across a wide area, the wet snow event in November 2005 in the M�nsterland region that caused power failures for up to 250.000 homes, and more recent snowstorms such as Daisy in January 2010. A catalogue of thresholds for relevant parameters indicating when significant failures can be expected is then compiled through a comparison of impact reports with the detailed meteorological conditions. Based on these findings, an exemplary synoptic evolution of a snowstorm leading to representative infrastructure failure cascades is constructed. In a next step, an extrapolation of this obtained scenario to future climate and societal conditions as well as plausible more extreme but not yet observed meteorological conditions is planned in order to obtain a thorough analysis of possible threats to the German food distribution system and a strong foundation for future disaster mitigation planning efforts.
von Wulffen, Anja
Winter speed-up of quiescent surge-type glaciers in Yukon, Canada
NASA Astrophysics Data System (ADS)
Glacier surge is known to often initiate in winter, but the mechanisms remain unclear in light of the summer speed-up at normal glaciers. We examined spatial-temporal changes in the ice velocity of surge-type glaciers near the border of Alaska and Yukon, and found significant upstream accelerations from fall to winter, regardless of surging episodes. Moreover, whereas the summer speed-up was observed downstream, the winter speed-up propagated from upstream to downglacier. Given the absence of upstream surface meltwater input in winter, we speculate the presence of water storages near the base that do not directly connect to the surface but can promote basal sliding through increased water pressure as winter approaches. Our findings have implications for modeling of glacial hydrology in winter time, and its link to glacier dynamics and subglacial erosion.
Abe, T.; Furuya, M.
Winter fog is decreasing in the fruit growing region of the Central Valley of California
NASA Astrophysics Data System (ADS)
Central Valley of California is home to a variety of fruit and nut trees. These trees account for 95% of the U.S. production, but they need a sufficient amount of winter chill to achieve rest and quiescence for the next season's buds and flowers. In prior work, we reported that the accumulation of winter chill is declining in the Central Valley. We hypothesize that a reduction in winter fog is cooccurring and is contributing to the reduction in winter chill. We examined a 33 year record of satellite remote sensing to develop a fog climatology for the Central Valley. We find that the number of winter fog events, integrated spatially, decreased 46%, on average, over 32 winters, with much year to year variability. Less fog means warmer air and an increase in the energy balance on buds, which amplifies their warming, reducing their chill accumulation more.
Baldocchi, Dennis; Waller, Eric
Daily movements of female mallards wintering in Southwestern Louisiana
Understanding daily movements of waterfowl is crucial to management of winter habitats, especially along the Gulf Coast where hunting pressure is high. Radio-telemetry was used to investigate movements of female Mallards (Anas platyrchychos) wintering in southwestern Louisiana. Movement distances were analyzed from 2,455 paired locations (diurnal and nocturnal) of 126 Mallards during winters 2004-2005 and 2005-2006 to assess effects of winter, female age, areas closed (Lacassine National Wildlife Refuge [LAC], Cameron Prairie National Wildlife Refuge [CAM], Amoco Pool [AMOCO] or open to hunting [OPEN]), and habitat type, including all interactions. Movement distances from the various land management categories were not consistent by age, date, or by winter. Flight distances from LAC increased with date, whereas those from CAM and OPEN did not vary significantly by date. Female Mallards moved short distances between diurnal and nocturnal sites (ranging from 3.1 to 15.0 km by land management category), suggesting that they are able to meet their daily energy requirements within a smaller area than Northern Pintails (Anas acuta, hereafter Pintails), and thus minimize transit energy costs.
Link, P. T.; Afton, A. D.; Cox, Jr. , R. R.; Davis, B. E.
Communicating Certainty About Nuclear Winter
NASA Astrophysics Data System (ADS)
I have been spending much of my time in the past several years trying to warn the world about the continuing danger of nuclear weapons, and that the solution is a rapid reduction in the nuclear arsenal. I feel that a scientist who discovers dangers to society has an ethical duty to issue a warning, even if the danger is so scary that it is hard for people to deal with. The debate about nuclear winter in the 1980s helped to end the nuclear arms race, but the planet still has enough nuclear weapons, even after reductions planned for 2017 under the New START treaty, to produce nuclear winter, with temperatures plunging below freezing in the summer in major agricultural regions, threatening the food supply for most of the planet. New research by myself, Brian Toon, Mike Mills, and colleagues over the past six years has found that a nuclear war between any two countries, such as India and Pakistan, using 50 atom bombs each of the size dropped on Hiroshima could produce climate change unprecedented in recorded human history, and a world food crisis because of the agricultural effects. This is much less than 1% of the current global arsenal. Communicating certainty - what we know for sure - has been much more effective than communicating uncertainty. The limited success I have had has come from persistence and serendipity. The first step was to do the science. We have published peer-reviewed articles in major journals, including Science, Nature, Proceedings of the National Academy of Sciences, Journal of Geophysical Research, Atmospheric Chemistry and Physics, Physics Today, and Climatic Change. But policymakers do not read these journals. Through fairly convoluted circumstances, which will be described in this talk, we were able to get papers published in Scientific American and the Bulletin of Atomic Scientists. I have also published several encyclopedia articles on the subject. As a Lead Author of Chapter 8 (Radiative Forcing) of the recently published Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), I inserted a paragraph pointing out that volcanic eruptions serve as an analog that supports new work on nuclear winter. This is the first time that nuclear winter has been in the IPCC report. I will tell the story of the discussions within our chapter, with review editors, and with the IPCC leadership that resulted in a box in Chapter 8 that discusses nuclear winter. We gave a briefing to John Holdren, the President's Science Advisor, about the work. Daniel Ellsberg, Fidel Castro, and Mikhail Gorbachev found out about our work, and used the results to appeal for nuclear abolition. In 2013 the work was featured at the Conference on the Humanitarian Impact of Nuclear Weapons in Oslo, Norway attended by 132 nations, and I gave a TEDx talk, I published an opinion piece on the CNN website, and I gave an invited public lecture in Nagasaki, Japan, all about the climatic consequences of nuclear war. I am now using Twitter and Facebook to communicate about nuclear winter. The threat that nuclear weapons pose to the planet is a much easier problem to solve than global warming. We need to eliminate nuclear weapons so we have the luxury of working on the global warming problem without the possibility of the existential global threat still posed by the global nuclear arsenal.
Robock, A.
Observed decreases in the Canadian outdoor skating season due to recent winter warming
Global warming has the potential to negatively affect one of Canada�s primary sources of winter recreation: hockey and ice skating on outdoor rinks. Observed changes in winter temperatures in Canada suggest changes in the meteorological conditions required to support the creation and maintenance of outdoor skating rinks; while there have been observed increases in the ice-free period of several natural
Nikolay N Damyanov; H Damon Matthews; Lawrence A Mysak
Microbial Biomass and Activities in Soil Aggregates Affected by Winter Cover Crops
vegetable cropping systems (Burket et al., 1997); how- ever, it is unclear whether legumes or nonlegumes are Winter cover crops may increase soil organic matter (SOM) and the most suitable for this task. Leguminous winter cover improve soil structure in intensively managed summer vegetable crop- ping systems. Our study examined the influence of three cover crop crops have the potential
I. C. Mendes; A. K. Bandick; R. P. Dick; P. J. Bottomley
Effect of Zinc on Cadmium Toxicity-Induced Oxidative Stress in Winter Wheat Seedlings
Two hydroponic experiments were conducted to investigate the antioxidant response of winter wheat (Triticum aestivum L.) to cadmium (Cd)-zinc (Zn) interactions, Seedlings of winter wheat (cv. Yuandong 977), were grown in modified Hoagland nutrient solution with the addition of increasing concentrations of Cd (0, 10, 25, 50 ?M). In experiment 2, the seedlings of the same cultivar were treated with
Z.-Q. Zhao; Y.-G. Zhu; R. Kneer; S. E. Smith
Winter lightning on Japan sea coast; Lightning striking frequency to tall structures
The nature of lightning striking tall structures on Japan sea coast in winter has been observed with automatically triggered camera and current measurements. The frequency of winter lightning striking tall structures is much higher than that of summer lightning and it increases proportionally to the height of structures. Sometimes lightning strikes simultaneously to multiple tall structures. Statistics of the striking
K. Miyake; T. Suzuki; M. Takashima; M. Takuma; T. Tada
Longitudinal Study of Disease Incidence among Antarctic Winter-Over Personnel.
National Technical Information Service (NTIS)
A longitudinal perspective was employed to test the hypothesis that there is an increased risk of hospitalization among Antarctic winter-over personnel during the first year subsequent to this duty. Subjects were 327 enlisted Navy men who wintered-over be...
L. A. Palinkas
Reproduction of Meloidogyne incognita on Winter Cover Crops Used in Cotton Production
Substantial reproduction of Meloidogyne incognita on winter cover crops may lead to damaging populations in a subse- quent cotton (Gossypium hirsutum) crop. The amount of population increase during the winter depends on soil temperature and the host status of the cover crop. Our objectives were to quantify M. incognita race 3 reproduction on rye (Secale cereale) and several leguminous cover
Patricia Timper; F. Davis
Winter MODIS observations of West Greenland fjord ice activity
NASA Astrophysics Data System (ADS)
Recent observations suggest that calving of West Greenland�s outlet glaciers typically ceases during winter months. However, increasingly long iceberg calving seasons pose a risk for increased dynamic thinning of Greenland�s outlet glaciers. Recent publications suggest that Jakobshavn Isbrae is one example of an outlet glacier that has recently begun to experience winter calving episodes. Records of such events are limited to local field campaigns that deploy seismometers and time-lapse photography. We have compiled a MODIS-derived 1-km daily Sea Surface Temperature (SST) record of several West Greenland fjords. This thermal record, which captures surface �temperature� records of fjord ice cover even during winter darkness, demonstrates that sudden, brief periods of warming, related to increased mobility of ice cover, or even open water, have occurred in traditionally frozen fjords, and that these periods coincide with published seismic data indicating calving from Jakobshavn Isbrae. The record of changes in fjord ice cover is compared with glacier terminus positions from the Landsat archive. Observations of coincident change are investigated. This study examines the use of the MODIS thermal record for year-round, near daily observations of the fjords fed by outlet glaciers, and introduces a potential tool for: 1). Spatially and temporally verifying seismically detected calving events in the fjords, and 2) monitoring the connection between the fjord ice cover and outlet glacier calving events during the winter months when visible band data is not available.
Cassotto, R. K.; Fahnestock, M. A.; Amundson, J. M.
Winter warming from large volcanic eruptions
An examination of the Northern Hemisphere winter surface temperature patterns after the 12 largest volcanic eruptions from 1883-1992 shows warming over Eurasia and North America and cooling over the Middle East which are significant at the 95 percent level. This pattern is found in the first winter after tropical eruptions, in the first or second winter after midlatitude eruptions, and in the second winter after high latitude eruptions. The effects are independent of the hemisphere of the volcanoes. An enhanced zonal wind driven by heating of the tropical stratosphere by the volcanic aerosols is responsible for the regions of warming, while the cooling is caused by blocking of incoming sunlight.
Robock, A.; Mao, J.
Winter warming from large volcanic eruptions
NASA Technical Reports Server (NTRS)
An examination of the Northern Hemisphere winter surface temperature patterns after the 12 largest volcanic eruptions from 1883-1992 shows warming over Eurasia and North America and cooling over the Middle East which are significant at the 95-percent level. This pattern is found in the first winter after tropical eruptions, in the first or second winter after midlatitude eruptions, and in the second winter after high latitude eruptions. The effects are independent of the hemisphere of the volcanoes. An enhanced zonal wind driven by heating of the tropical stratosphere by the volcanic aerosols is responsible for the regions of warming, while the cooling is caused by blocking of incoming sunlight.
Robock, Alan; Mao, Jianping
An assessment of the potential and impacts of winter water banking in the Sokh aquifer, Central Asia
The dynamics of artificial recharge of winter surface flows coupled with increased summer groundwater use for irrigation in\\u000a the Sokh aquifer (Central Asia) have been investigated. Water release patterns from the giant Toktogul reservoir have changed,\\u000a as priority is now given to hydropower generation in winter in Kyrgyzstan. Winter flows have increased and summer releases\\u000a have declined, but the Syr
Inna Gracheva; Akmal Karimov; Hugh Turral; F. Miryusupov
Inverse simulation of snowmelt runoff and snow cover area using the energy balance-based distributed snowmelt model (WEB-DHM-S) for the correction of basin-scale snowfall
NASA Astrophysics Data System (ADS)
In this study, a method has been established that explicitly corrects the basin-scale snowfall amount through the inverse simulation of snowmelt runoff and snow cover area (SCA) with the use of the multilayer energy balance based distributed snowmelt model (WEB-DHM-S). The evaluation indices, obtained from the pixel-to-pixel analysis between the simulated SCA and the SCA derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard the Terra Satellite, and from the statistical analysis between the simulated and observed snowmelt runoff, were used to define the threshold criteria for the minimization of bias/maximization of accuracy following the calibration of the orography-dependent snowfall correction factor (SCF). The method was applied at Yagisawa basin (167 km2) of the Upper Tone River of Japan. The model was run at hourly time step at 500 m grid from November 2000 to November 2004. Two types of precipitation (observed rain gauge, called AMeDAS and Radar data adjusted with rain gauge observations, called Radar-AMeDAS) inputs were corrected with this approach since both dataset highly underestimated the snowmelt runoff due to large underestimation of snowfall. The basin average SCF was estimated at 1.87 times for AMeDAS and at 3.77 times for Radar-AMeDAS precipitation, for which Nash Efficiency was greater than 0.80, and the overall accuracy of SCA simulation between the MODIS and the model was about 91%. The method established in this study is simple and robust, and can be applied to any snow-fed river basin to obtain a reliable SCF. Furthermore, this approach could be applicable in correcting the snowfall from reanalysis products and atmospheric model outputs which could be very supportive in the climate and land surface hydrological researches.
Shrestha, M.; Wang, L.; Koike, T.; Tsutsui, H.; Xue, Y.; Hirabayashi, Y.
Winter Olympics Physics and Biomechanics
NSDL National Science Digital Library
Many Winter Olympic sports are greatly dependent on technique, engineering, and/or gravity. For example, during luge, while gravity is accelerating the sled up to 80 mph down the track, the slider must use good technique to steer the sled and minimize air resistance. To excel in these type of sports, it is helpful to have a full appreciation of physics and biomechanics. Physics is a broad field which includes mechanics, electricity, magnetism, optics, etc., and biomechanics is the study of the mechanics of living systems. In the module we will use the sports of luge and figure skating to teach you four basic mechanical concepts: linear kinematics, linear dynamics, projectile motion, and conservation of angular momentum. In addition, we have developed a glossary which defines and illustrates all the physics terminology you will need to complete this module.
Shifting covariability of North American summer monsoon precipitation with antecedent winter precipitation
Previous research has suggested that a general inverse relation exists between winter precipitation in the southwestern United states (US) and summer monsoon precipitation. In addition, it has been suggested that this inverse relation between winter precipitation and the magnitude of the southwestern US monsoon breaks down under certain climatic conditions that override the regional winter/monsoon precipitation relations. Results from this new study indicate that the winter/monsoon precipitation relations do not break down, but rather shift location through time. The strength of winter/monsoon precipitation relations, as indexed by 20-year moving correlations between winter precipitation and monsoon precipitation, decreased in Arizona after about 1970, but increased in New Mexico. The changes in these correlations appear to be related to an eastward shift in the location of monsoon precipitation in the southwestern US. This eastward shift in monsoon precipitation and the changes in correlations with winter precipitation also appear to be related to an eastward shift in July/August atmospheric circulation over the southwestern US that resulted in increased monsoon precipitation in New Mexico. Results also indicate that decreases in sea-surface temperatures (SSTs) in the central North Pacific Ocean also may be associated with th changes in correlations between winter and monsoon precipitation. Copyright ?? 2006 Royal Meteorological Society.
McCabe, G. J.; Clark, M. P.
A New East Asian Winter Monsoon Index and Associated Characteristics of the Winter Monsoon
A new East Asian winter monsoon index, which reflects the 300-hPa meridional wind shear associated with the jet stream, was defined to describe the variability of the winter monsoon in midlatitude East Asia. This index represents very well the seasonal mean winter temperature over Korea, Japan, and eastern China. The National Centers for Environmental Prediction National Center for Atmospheric Research
Jong-Ghap Jhun; Eun-Jeong Lee
Characterization of an unexpected snowfall event in Iqaluit, Nunavut, and surrounding area during the Storm Studies in the Arctic field project
NASA Astrophysics Data System (ADS)
accumulation precipitation events are critical for the high-latitude hydrological cycle. They contribute to more than 50% of total accumulation in the area and occur at a greater frequency than high-accumulation events. Despite their importance, the processes controlling them have not been investigated in sufficient detail. This study characterizes an unexpected high-latitude snowfall event at Iqaluit, Nunavut, and surrounding area during the Storm Studies in the Arctic field project. High-resolution data collected, from both ground based and airborne Doppler radar, along with upper air and surface observations, provided the basis for analysis of the conditions that led to the event and offer some insight as to why it was not well forecast by the Canadian operational model. Several factors worked in concert to produce this event. Low-level convection and upslope processes were important in cloud and precipitation generation over the orography upstream. When combined with additional lift from the passing of a weak trough, cloud and precipitation production were enhanced, allowing these features to penetrate over the terrain and resulted in precipitation at Iqaluit. Analysis of the global environmental multiscale limited area model (2.5 km resolution) suggests that upstream convection and upslope processes were affected by model errors. As a consequence, precipitation onset was delayed, and the total accumulation was 50% lower than the observations. Results indicate that the complexity of precipitation events in the region represents a significant challenge for predicting and modeling and understanding their role in the region's hydrological cycle.
Fargey, S.; Henson, W.; Hanesiak, J.; Goodson, R.
A Large-Droplet Mode and Prognostic Number Concentration of Cloud Droplets in the Colorado State University Regional Atmospheric Modeling System (RAMS). Part II: Sensitivity to a Colorado Winter Snowfall Event
This paper is the second in a two-part series describing recent additions to the microphysics module of the Regional Atmospheric Modeling System (RAMS) at Colorado State University. These changes include the addition of a large-cloud-droplet mode (40-80 m in diameter) into the liquid-droplet spectrum and the parameterization of cloud-droplet nucleation through activation of cloud condensation nuclei (CCN) and giant CCN
Stephen M. Saleeby; William R. Cotton
PLCO News, Fall/Winter 1998 Volume 1, Number 2 ----- Fall/Winter 1998 Cancer Information Center If you have a question about cancer you can call and speak with a trained specialist at NCI's Cancer Information Service (CIS). The CIS operates a toll-free,
PLCO News, Fall/Winter 1998 Volume 1, Number 2 ----- Fall/Winter 1998 Trial Update Enrollment goal: 148,000 Total enrollment (as of September 30, 1998): 111,515 Men enrolled: 58,283 Women enrolled: 53,232 Number of people enrolled
Shifting mirrors: adaptive changes in retinal reflections to winter darkness in Arctic reindeer
Arctic reindeer experience extreme changes in environmental light from continuous summer daylight to continuous winter darkness. Here, we show that they may have a unique mechanism to cope with winter darkness by changing the wavelength reflection from their tapetum lucidum (TL). In summer, it is golden with most light reflected back directly through the retina, whereas in winter it is deep blue with less light reflected out of the eye. The blue reflection in winter is associated with significantly increased retinal sensitivity compared with summer animals. The wavelength of reflection depends on TL collagen spacing, with reduced spacing resulting in shorter wavelengths, which we confirmed in summer and winter animals. Winter animals have significantly increased intra-ocular pressure, probably produced by permanent pupil dilation blocking ocular drainage. This may explain the collagen compression. The resulting shift to a blue reflection may scatter light through photoreceptors rather than directly reflecting it, resulting in elevated retinal sensitivity via increased photon capture. This is, to our knowledge, the first description of a retinal structural adaptation to seasonal changes in environmental light. Increased sensitivity occurs at the cost of reduced acuity, but may be an important adaptation in reindeer to detect moving predators in the dark Arctic winter.
Stokkan, Karl-Arne; Folkow, Lars; Dukes, Juliet; Neveu, Magella; Hogg, Chris; Siefken, Sandra; Dakin, Steven C.; Jeffery, Glen
Shifting mirrors: adaptive changes in retinal reflections to winter darkness in Arctic reindeer.
Arctic reindeer experience extreme changes in environmental light from continuous summer daylight to continuous winter darkness. Here, we show that they may have a unique mechanism to cope with winter darkness by changing the wavelength reflection from their tapetum lucidum (TL). In summer, it is golden with most light reflected back directly through the retina, whereas in winter it is deep blue with less light reflected out of the eye. The blue reflection in winter is associated with significantly increased retinal sensitivity compared with summer animals. The wavelength of reflection depends on TL collagen spacing, with reduced spacing resulting in shorter wavelengths, which we confirmed in summer and winter animals. Winter animals have significantly increased intra-ocular pressure, probably produced by permanent pupil dilation blocking ocular drainage. This may explain the collagen compression. The resulting shift to a blue reflection may scatter light through photoreceptors rather than directly reflecting it, resulting in elevated retinal sensitivity via increased photon capture. This is, to our knowledge, the first description of a retinal structural adaptation to seasonal changes in environmental light. Increased sensitivity occurs at the cost of reduced acuity, but may be an important adaptation in reindeer to detect moving predators in the dark Arctic winter. PMID:24174115
Stokkan, Karl-Arne; Folkow, Lars; Dukes, Juliet; Neveu, Magella; Hogg, Chris; Siefken, Sandra; Dakin, Steven C; Jeffery, Glen
Stimulation of Phospholipid Biosynthesis during Frost Hardening of Winter Wheat.
Lipids were labeled with (33)P during frost hardening of two varieties of winter wheat (Triticum aestivum), hardy Kharkov and much less hardy Champlein. The main labeled compounds were phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, and phosphatidylglycerol. With time of incorporation the proportion of the radioactivity incorporated into the lipids increased in phosphatidylcholine, especially in Kharkov and at 1 C. During hardening, phospholipid synthesis was greatly stimulated in Kharkov, but much less in Champlein. The proportion of the phospholipids synthesized changed only little with hardening, with a trend towards an increase in phosphatidylcholine. Increased phospholipid synthesis does not seem to be a prerequisite to hardening in winter wheat. However, a high rate of phospholipid synthesis may be required to maintain frost resistance. PMID:16659082
Willemot, C
Winter availability of cereal stubbles attracts declining farmland birds and positively influences breeding population trends
Many studies have demonstrated the selection of stubble fields by farmland birds in winter, but none have shown whether provisioning of this key habitat positively influences national population trends for widespread farmland birds. We use two complementary extensive bird surveys undertaken at the same localities in summer and winter and show that the area of stubble in winter attracts increased numbers of several bird species of conservation concern. Moreover, for several farmland specialists, the availability of stubble fields in winter positively influenced the 10 year breeding population trend (1994�2003) whereas hedgerow bird species were less affected. For skylarks and yellowhammers, initially negative trends showed recovery with 10�20?ha of stubble per 1?km square. Thus, agri-environment schemes that promote retention of over-winter stubbles will attract birds locally and are capable of reversing current population declines if stubbles are available in sufficient quantity.
Gillings, Simon; Newson, Stuart E; Noble, David G; Vickery, Juliet A
Winter availability of cereal stubbles attracts declining farmland birds and positively influences breeding population trends.
Many studies have demonstrated the selection of stubble fields by farmland birds in winter, but none have shown whether provisioning of this key habitat positively influences national population trends for widespread farmland birds. We use two complementary extensive bird surveys undertaken at the same localities in summer and winter and show that the area of stubble in winter attracts increased numbers of several bird species of conservation concern. Moreover, for several farmland specialists, the availability of stubble fields in winter positively influenced the 10 year breeding population trend (1994-2003) whereas hedgerow bird species were less affected. For skylarks and yellowhammers, initially negative trends showed recovery with 10-20 ha of stubble per 1 km square. Thus, agri-environment schemes that promote retention of over-winter stubbles will attract birds locally and are capable of reversing current population declines if stubbles are available in sufficient quantity. PMID:15870035
Gillings, Simon; Newson, Stuart E; Noble, David G; Vickery, Juliet A
Nitrate sequestration by corticolous macrolichens during winter precipitation events.
Nitrogen is an essential nutrient in the biogeochemistry of forested ecosystems. The influence of canopy lichens on the winter biogeochemistry of nitrate in broadleaved deciduous forests is examined and it is hypothesized that nitrate sequestration will not differ between winter precipitation events. Rejection of this hypothesis would mean that meteorological conditions of winter precipitation events have a detectable influence on nitrate sequestration by canopy lichens and nitrate input to the forest floor. Canopy lichens of the genus Parmelia were found to influence winter nitrate stemflow inputs to forest soils differentially. Epiphytic lichens on an individual Carya glabra Mill. (pignut hickory) canopy tree, centrally located within the stand of an open deciduous forest, actively sequestered nitrate leached from the tree's woody frame, lowering aqueous stemflow inputs at the tree base. The quantities of nitrate sequestered by corticolous lichens during the 2 February 1999 mixed-precipitation event were significantly greater than those during all other precipitation events examined. Greater rates of nitrate uptake during the 2 February 1999 event may be attributed to (1) its intermediate rain intensity, which would have soaked the lichen thalli in a nutrient-rich bath, and (2) an air temperature range between -2 degrees C and 8 degrees C that would have increased viscosity and surface tension of stemflow drainage, thereby decreasing stemflow velocity and increasing the contact time of stemflow water on the lichen thalli. Other precipitation events were either too cold to promote metabolic activity by canopy lichens or too warm and intense for an optimal contact time of stemflow with lichen thalli, resulting in lower quantities of nitrate sequestered. Meteorological conditions of winter precipitation events have been documented to influence sequestration of nitrate by corticolous lichens and decrease aqueous stemflow inputs to the forest floor of broadleaved deciduous forests. PMID:12135200
Levia, Delphis F
Antifreeze Proteins in Winter Rye Leaves Form Oligomeric Complexes1
Antifreeze proteins (AFPs) similar to three pathogenesis-related proteins, a glucanase-like protein (GLP), a chitinase-like protein (CLP), and a thaumatin-like protein (TLP), accumulate during cold acclimation in winter rye (Secale cereale) leaves, where they are thought to modify the growth of intercellular ice during freezing. The objective of this study was to characterize the rye AFPs in their native forms, and our results show that these proteins form oligomeric complexes in vivo. Nine proteins were separated by native-polyacrylamide gel electrophoresis from apoplastic extracts of cold-acclimated winter rye leaves. Seven of these proteins exhibited multiple polypeptides when denatured and separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. After isolation of the individual proteins, six were shown by immunoblotting to contain various combinations of GLP, CLP, and TLP in addition to other unidentified proteins. Antisera produced against individual cold-induced winter rye GLP, CLP, and TLP all dramatically inhibited glucanase activity in apoplastic extracts from cold-acclimated winter rye leaves, and each antiserum precipitated all three proteins. These results indicate that each of the polypeptides may be exposed on the surface of the protein complexes. By forming oligomeric complexes, AFPs may form larger surfaces to interact with ice, or they may simply increase the mass of the protein bound to ice. In either case, the complexes of AFPs may inhibit ice growth and recrystallization more effectively than the individual polypeptides.
Yu, Xiao-Ming; Griffith, Marilyn
Occurrence of winter air temperature extremes in Central Spitsbergen
NASA Astrophysics Data System (ADS)
The occurrence of daily air temperature extremes in winter in Central Spitsbergen in the period 1975-2008 was analysed. The mean winter temperature was found to be increasing by approximately 1.65�C per decade. Negative extremes were becoming less frequent, decreasing at a rate of approximately 5 days per decade, whereas the frequency of positive extremes showed a small (2 days per decade) but insignificant positive trend. Furthermore, circulation patterns responsible for positive and negative temperature extremes were analysed. Composite maps of the sea level pressure (SLP) and 500-hPa geopotential heights (z500 hPa) means and anomalies were constructed for the days with positive and negative extremes. Circulation patterns causing extremely warm winter days are characterised by a cyclonic centre or a low pressure trough over the Fram Strait. Cyclones located west of Spitsbergen with a warm sector over the archipelago bring warm air masses from the southern quadrant. On extremely cold days, the cyclone centres are usually located over the Barents Sea. This SLP pattern implies airflow from the north and northeast that brings cold Arctic air to the North Atlantic. Another factor in the occurrence of the temperature extremes in Central Spitsbergen is the sea-ice cover. Negative temperature extremes usually occur together with a high concentration of sea ice, particularly in the middle and end of winter.
Bednorz, Ewa
Monitoring the global-scale winter anomaly of total electron contents using GPS data
NASA Astrophysics Data System (ADS)
The winter anomaly phenomenon of Total Electron Contents (TEC) at latitudes 15�-60�N and 15�S-60�S is presented using GPS carrier-phase data obtained from GPS stations during 2002. The correlation between the [O/N2] ratio estimated using the NRLMSISE-00 atmospheric model and the TEC winter anomaly is also investigated. The numerical results show that the TEC winter anomaly in different regions of the world tends to be dominated by different factors. In North America, the TEC winter anomaly is strongly affected by the magnetospheric processes in high latitudes and the [O/N2] ratio. In the Euro-Africa and Russia-Asia regions, the TEC winter anomaly depends mainly on the [O/N2] ratio at the latitude band of 30�-60�N, and the extent of the TEC winter anomaly gradually decreases from 60�N to 30�N. The extent of the TEC winter anomaly increases at the latitude band of 15�-30�N due to the influence of the meridional neutral wind and the seasonal changes of the subsolar point. However, the TEC winter anomaly was not observed in southern hemisphere in 2002. The TEC equinoctial asymmetries in the northern and southern hemisphere are also presented using GPS TEC values collected in March and September 2002.
Huo, X. L.; Yuan, Y. B.; Ou, J. K.; Zhang, K. F.; Bailey, G. J.
Density- and Size-Dependent Winter Mortality and Growth of Late Chaoborus flavicans Larvae
Winter processes such as overwinter survival and growth of individuals can have wide-ranging consequences for population dynamics and communities within and across seasons. In freshwater organisms winter processes have been mainly studied in fish despite that invertebrates also have substantial impacts on lake and pond food webs. One of the major invertebrate consumers in lake and ponds is the planktonic larvae of the dipteran insect Chaoborus spec. However, while much is known about Chaoborus feeding ecology, behaviour and structuring role in food webs, its winter ecology and how it affects its populations are poorly understood. Here size- and density-dependent winter mortality and body growth of late Chaoborus flavicans larvae were quantified over naturally occurring size and density ranges in autumn and under natural winter conditions using two field enclosure experiments. Winter mortality increased with autumn density but decreased with autumn body size while winter growth rates decreased with autumn density and body sizes. There was also a density- and size-independent background mortality component. The proportion of pupae found in spring decreased strongly and exponentially with autumn density. These results may explain the commonly observed univoltine life cycle and multi-annual density fluctuations in northern Chaoborus populations. They further demonstrate the relevance of winter processes and conditions for freshwater invertebrates and ecosystems.
Schroder, Arne
The History of Winter and the Global Snowflake Network, Engaging Teachers and Students in Science Field Research in Snow and Ice
NASA Astrophysics Data System (ADS)
A weeklong Professional development/"Teacher as scientist" Cryosphere science training camp held annually in February in Lake Placid, NY, the History of Winter program (HOW) has been serving teachers in the NASA Goddard Space Flight Center service area since 2000. Currently, HOW participants include university faculty interested in enhancing their pre-service science education programs, in-service teachers and pre-service education students. HOW utilizes a stratified professional development approach to science content mastery and delivery while involving participants in scientific field research. Each year program components and resources are added to HOW to provide continued, sustainable interest in the program and to support participants as they continue their HOW experience. An offshoot of the HOW Program, the Global Snowflake Network (GSN) launched in the winter of 2006 engages an international audience including both formal and informal education groups. The goal is to provide an interactive online data resource in science and education for the characterization of snowfall and related weather systems. The Global Snowflake Network has been accepted as an education outreach proposal for the International Polar Year. Collaborations with other agencies and universities also with IPY-accepted proposals are now underway. HOW and the GSN are endorsed by the NASA Goddard Education Office and many of the Goddard Snow and Ice scientists. Together these programs offer a unique, sustainable, and proven outreach for the Cryosphere research program.
Bender, K. J.; Wasilewski, P. J.; Gabrys, R. E.
Enhancement of Winter Maintenance Material Ordering and Inventory, Executive Summary.
National Technical Information Service (NTIS)
Availability of winter maintenance materials is the foundation upon which successful winter maintenance operations are built. Maintaining high levels of service during and following winter storms has a critical impact on sustaining economic activity and e...
F. W. Ciarallo
76 FR 73503 - Amendment of Class E Airspace; Winters, TX
Federal Register 2010, 2011, 2012, 2013
...11-ASW-7] Amendment of Class E Airspace; Winters, TX AGENCY: Federal Aviation Administration...SUMMARY: This action amends Class E airspace for Winters, TX. Decommissioning of the Winters non-directional beacon (NDB) and...
Characteristics of Winter Lightning Currents Struck an Isolated Tower.
National Technical Information Service (NTIS)
To make clear the characteristics of winter lightning flashes, the current waveforms of winter lightning flashes were measured by two resistive shunts which were connected to two lighting rods since the winter of 1981, and another measurement has started ...
Y. Goto K. Narita H. Komuro
Impacts of winter storms on air-sea gas exchange
NASA Astrophysics Data System (ADS)
The objective of this study is to investigate air-sea gas exchange during winter storms, using field measurements from Ocean Station Papa in the Northeast Pacific (50�N, 145�W). We show that increasing gas transfer rates are coincident with increasing winds and deepening depth of bubble penetration, and that this process depends on sea state. Wave-breaking is shown to be an important factor in the gas transfer velocity during the peaks of the storms, increasing the flux rates by up to 20%. Gas transfer rates and concentrations can exhibit asymmetry, reflecting a sudden increase with the onset of a storm, and gradual recovery stages.
Zhang, Weiqing; Perrie, Will; Vagle, Svein
Hibernation in an Antarctic Fish: On Ice for Winter
Active metabolic suppression in anticipation of winter conditions has been demonstrated in species of mammals, birds, reptiles and amphibians, but not fish. This is because the reduction in metabolic rate in fish is directly proportional to the decrease in water temperature and they appear to be incapable of further suppressing their metabolic rate independently of temperature. However, the Antarctic fish (Notothenia coriiceps) is unusual because it undergoes winter metabolic suppression irrespective of water temperature. We assessed the seasonal ecological strategy by monitoring swimming activity, growth, feeding and heart rate (fH) in N. coriiceps as they free-ranged within sub-zero waters. The metabolic rate of wild fish was extrapolated from fH recordings, from oxygen consumption calibrations established in the laboratory prior to fish release. Throughout the summer months N. coriiceps spent a considerable proportion of its time foraging, resulting in a growth rate (Gw) of 0.18�0.2% day?1. In contrast, during winter much of the time was spent sedentary within a refuge and fish showed a net loss in Gw (?0.05�0.05% day?1). Whilst inactive during winter, N. coriiceps displayed a very low fH, reduced sensory and motor capabilities, and standard metabolic rate was one third lower than in summer. In a similar manner to other hibernating species, dormancy was interrupted with periodic arousals. These arousals, which lasted a few hours, occurred every 4�12 days. During arousal activity, fH and metabolism increased to summer levels. This endogenous suppression and activation of metabolic processes, independent of body temperature, demonstrates that N. coriiceps were effectively �putting themselves on ice� during winter months until food resources improved. This study demonstrates that at least some fish species can enter a dormant state similar to hibernation that is not temperature driven and presumably provides seasonal energetic benefits.
Campbell, Hamish A.; Fraser, Keiron P. P.; Bishop, Charles M.; Peck, Lloyd S.; Egginton, Stuart
Explaining unusual winter lightning in Japan
NASA Astrophysics Data System (ADS)
Third International Symposium on Winter Lightning; Sapporo, Japan, 15-16 June 2011 Japan's meteorological setting in winter is unusual: It is an island in a relatively warm sea frequently overswept by colder air from Siberia. This sets up appreciable atmospheric instability in the fringe of the land adjacent to the Sea of Japan. Heavy snowstorms overlap the edge of the island and produce extraordinarily energetic lightning flashes that initiate from points on the ground (known as ground-to-cloud (GC) strokes) and wreak havoc on power lines and, more recently, wind turbines. These troublesome and costly conditions set the stage for the third in a series of conferences on winter lightning.
Shindo, Takatoshi; Ishii, Masaru; Williams, Earle
Blood chemistry of reindeer calves (Rangifer tarandus) during the winter season.
1. Blood characteristics of reindeer calves fed on lichens were studied during the winter. 2. The serum total protein, albumin and globulin concentrations decreased during the winter, obviously partly due to protein deficiency in the diet. 3. High urea levels in autumn and midwinter were possibly reflections of increased stress and/or protein catabolism. 4. Marked lipolysis occurred in late winter, and thus increases were observed in fatty acids, glycerol, triglycerides and acetoacetate concentrations. 5. Serum sorbitol dehydrogenase (SDH) activity increased towards the spring, most probably reflecting changes in the liver. 6. A decrease in serum alkaline phosphatase (AP) activity occurred in midwinter due to cessation of growth. 7. It can be concluded that all the animals were at least in moderate condition throughout the winter and the physiological responses to a negative energy balanced reflected good adaptation. PMID:1351815
Soveri, T; Sankari, S; Nieminen, M
The urban heat island in winter at Barrow, Alaska
NASA Astrophysics Data System (ADS)
The village of Barrow, Alaska, is the northernmost settlement in the USA and the largest native community in the Arctic. The population has grown from about 300 residents in 1900 to more than 4600 in 2000. In recent decades, a general increase of mean annual and mean winter air temperature has been recorded near the centre of the village, and a concurrent trend of progressively earlier snowmelt in the village has been documented. Satellite observations and data from a nearby climate observatory indicate a corresponding but much weaker snowmelt trend in the surrounding regions of relatively undisturbed tundra. Because the region is underlain by ice-rich permafrost, there is concern that early snowmelt will increase the thickness of the thawed layer in summer and threaten the structural stability of roads, buildings, and pipelines. Here, we demonstrate the existence of a strong urban heat island (UHI) during winter. Data loggers (54) were installed in the 150 km2 study area to monitor hourly air and soil temperature, and daily spatial averages were calculated using the six or seven warmest and coldest sites. During winter (December 2001-March 2002), the urban area averaged 2.2 �C warmer than the hinterland. The strength of the UHI increased as the wind velocity decreased, reaching an average value of 3.2 �C under calm (<2 m s-1) conditions and maximum single-day magnitude of 6 �C. UHI magnitude generally increased with decreasing air temperature in winter, reflecting the input of anthropogenic heat to maintain interior building temperatures. On a daily basis, the UHI reached its peak intensity in the late evening and early morning. There was a strong positive relation between monthly UHI magnitude and natural gas production/use. Integrated over the period September-May, there was a 9% reduction in accumulated freezing degree days in the urban area. The evidence suggests that urbanization has contributed to early snowmelt in the village.
Hinkel, Kenneth M.; Nelson, Frederick E.; Klene, Anna E.; Bell, Julianne H.
Near cessation of Eighteen Degree Water renewal in the western North Atlantic in the warm winter of 2011-2012
NASA Astrophysics Data System (ADS)
The winter of 2011-2012 was a particularly weak season for the renewal of "Eighteen Degree Water" (EDW), the Subtropical Mode Water of the western North Atlantic, as demonstrated by Argo and repeat hydrography. Weak, late winter buoyancy forcing produced shallower than usual winter mixed layers throughout the subtropical gyre, failing to thoroughly ventilate the underlying mode water, and can likely be attributed to the coinciding high, positive phase of the North Atlantic Oscillation (NAO). The only region where EDW was renewed was in the far northeastern Sargasso Sea where it is understood that the Gulf Stream plays a central role in formation; no EDW formed over the large regions of the gyre where deep winter mixed layers driven by surface buoyancy loss normally create EDW. The present investigation evaluates 2011-2012 winter buoyancy content anomalies, surface buoyancy fluxes, and advection of buoyancy via the Gulf Stream and compares them with the previous seven winters that exhibited more vigorous EDW formation. The weak 2011-2012 formation did not result from increased Gulf Stream heat advection, and was also not driven by preconditioning as the buoyancy content of the region prior to the onset of winter forcing was not unusually high. Rather, the weak formation resulted from climatologically weak surface cooling late in winter. The winter of 2007-2008 also experienced particularly weak EDW formation under similar conditions, including a high NAO and weak late winter surface cooling.
Billheimer, Sam; Talley, Lynne D.
Natural Gas Price Increases: A Preliminary Analysis.
National Technical Information Service (NTIS)
Natural gas prices in many cities are expected to increase substantially this winter. This preliminary analysis addresses--how much prices have increased since 1970 to residential, industrial, and other users nationwide and to residential users in selecte...
Development of a model system to identify differences in spring and winter oat.
Our long-term goal is to develop a Swedish winter oat (Avena sativa). To identify molecular differences that correlate with winter hardiness, a winter oat model comprising of both non-hardy spring lines and winter hardy lines is needed. To achieve this, we selected 294 oat breeding lines, originating from various Russian, German, and American winter oat breeding programs and tested them in the field in south- and western Sweden. By assaying for winter survival and agricultural properties during four consecutive seasons, we identified 14 breeding lines of different origins that not only survived the winter but also were agronomically better than the rest. Laboratory tests including electrolytic leakage, controlled crown freezing assay, expression analysis of the AsVrn1 gene and monitoring of flowering time suggested that the American lines had the highest freezing tolerance, although the German lines performed better in the field. Finally, six lines constituting the two most freezing tolerant lines, two intermediate lines and two spring cultivars were chosen to build a winter oat model system. Metabolic profiling of non-acclimated and cold acclimated leaf tissue samples isolated from the six selected lines revealed differential expression patterns of 245 metabolites including several sugars, amino acids, organic acids and 181 hitherto unknown metabolites. The expression patterns of 107 metabolites showed significant interactions with either a cultivar or a time-point. Further identification, characterisation and validation of these metabolites will lead to an increased understanding of the cold acclimation process in oats. Furthermore, by using the winter oat model system, differential sequencing of crown mRNA populations would lead to identification of various biomarkers to facilitate winter oat breeding. PMID:22253782
Chawade, Aakash; Lind�n, Pernilla; Br�utigam, Marcus; Jonsson, Rickard; Jonsson, Anders; Moritz, Thomas; Olsson, Olof
Winter Morning in Northern Tharsis
NASA Technical Reports Server (NTRS)
Mars Global Surveyor's camera, MOC, provided this hemispheric view of the northern Tharsis region on June 1, 1998. This picture shows the giant volcano, Olympus Mons, and one of the Tharsis Montes volcanoes, Ascraeus Mons. Another volcano, Alba Patera, is lurking under the haze and clouds at the top of the image. Olympus Mons is about 550 kilometers (340 miles) wide.MGS is now in a 'morning' orbit (when it arrived at Mars in September 1997, it was inserted into a 'late afternoon' orbit). The orbit will continue to change, about one hour a month, until aerobraking into a circular orbit is complete about seven months from now. When this picture was taken, the local time on the ground beneath the spacecraft was about 9:30 a.m. The terminator-- the line that divides night and day-- was located west of Olympus Mons (left part of the image). It is winter in the northern hemisphere of Mars, and the high latitudes (i.e., north of Olympus Mons in this picture) exhibit clouds and haze. These clouds most likely contain water ice.MOC images 33901 (the red wide angle image) and 33902 (the blue wide angle image) were obtained on Mars Global Surveyor's 339th orbit about the planet. The pictures were taken around 7:37 p.m. PDT on June 1, 1998.Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.
Mesoscale Aspects of Winter Weather Forecasting Topics
NSDL National Science Digital Library
The Mesoscale Aspects of Winter Weather Forecasting effort is comprised of a growing series of in-depth case exercises bundled with supporting topics. This site provides access to the supporting topics seperate from the case exercises.
Spangler, Tim
Mesoscale Precipitation Systems in Winter Storms.
National Technical Information Service (NTIS)
Heavy frozen precipitation produced by complex mesoscale patterns embedded within winter extratropical cyclones (ETCs) adversely affect many areas of the United States each year. The initiation, organization, and movement of these mesoscale precipitation ...
M. A. Kaster
Winter warming from large volcanic eruptions
An examination of the Northern Hemisphere winter surface temperature patterns after the 12 largest volcanic eruptions from 1883-1992 shows warming over Eurasia and North America and cooling over the Middle East which are significant at the 95% level. This pattern is found in the first winter after tropical eruptions, in the first or second winter after midlatitude eruptions, and in the second winter after high latitude eruptions. The effects are independent of the hemisphere of the volcanoes. An enhanced zonal wind driven by heating of the tropical stratosphere by the volcanic aerosols is responsible for the regions of warming, while the cooling is caused by blocking of incoming sunlight. 21 refs., 2 figs., 1 tab.
Robock, A.; Jianping Mao (Univ. of Maryland, College Park (United States))
VESTA Viticulture Course: Winter Viticulture Technology
NSDL National Science Digital Library
This site, from the Viticulture and Enology Science and Technology Alliance, offers presentations and slides from the lectures of VIN 113: Winter Viticulture Technology. From the presenter, Katie Gill, the lectures cover such topics as pruning and winter grapevine anatomy. Each topic includes a multimedia presentation of the lecture, with slides. Users must have Microsoft's Silverlight installed to view the presentations, which vary in length from about 2 minutes to 7 minutes.
Record-breaking Ozone Loss during Arctic Winter 2010/2011: Comparison with Arctic Winter 1996/1997
NASA Astrophysics Data System (ADS)
Polar processing and chemical ozone loss is analysed during the Arctic winter/spring 2010/2011. The analyses with temperatures and potential vorticity (PV) data show a prolonged vortex from early December through mid-April. The PV maps illustrate strong vortex persistence in the lower stratosphere between 450 and 675 K, showing similar evolution with time. The minimum temperatures extracted from ECMWF data at 40-90�N show values below 195 K for a record period of first week of December through second week of April, indicating the longest period of colder temperatures for 17 years. At 10 hPa, there was a warming of about 10 K at 60�N and 40 K at 90�N around mid-January. The heat flux also showed high values in line with the increase in temperatures, of about 425 m K/s at 60�N at the same pressure level. However, the westerlies were strong (e.g. 35-45 m/s at 60�N) enough to keep the vortex intact until mid-April. Because of the cold temperatures in late winter and early spring, large areas of Polar Stratospheric Clouds (PSC) were found in the 400-600 K isentropic level range. Though the maximum values of PSCs area are smaller compared to other cold winters such as 2005, the extended period of presence of PSCs during this winter was exceptional, especially in late February-mid-March, in agreement with the cold temperatures during the period. Ozone loss analyses with high resolution Mimosa-Chim chemical transport model simulations show that the loss started by early January, and was about 0.5 ppmv in late January. The loss progressed slowly to 1 ppmv by the end of February, and then intensified by early March. The ozone depletion estimated by the passive method finds a maximum value of about 2-2.3 ppmv by the end of March-early April in the 450-550K range inside the vortex, which coincides with the areas of PSCs and high chlorine activation. This is the largest loss ever estimated with this model for any Arctic winter. It is consistent with the unprecedented chlorine activation that occurred in the winter, as the modeled ClO values show about 1.7 ppbv in early January and about 1 ppbv in March at 450-550K. This is longest period of chlorine activation noted among the Arctic winters. The ozone partial column loss reaches about 115-150 DU in the range 350 - 550 K. These model results for ozone, ozone loss and ClO are in good agreement with those found from Aura Microwave Limb Sounder observations. Since the winter 1996/1997 was also very cold in March - April, a comparison between both winters 2011 and 1997 will be presented, based on temperature, PV, Heat flux data and ozone loss estimations. Similarities and differences in the polar processing and ozone loss during both winters will be discussed using various measurements and model simulations. Copyright 2011. All rights reserved.
Godin Beekmann, S.; Kuttipurath, J.; Lef�vre, F.; Santee, M. L.; Froidevaux, L.
Key areas for wintering North American herons
Nearly all North American heron populations are migratory, but details of where they winter are little known. Locations where North American herons winter were identified using banding recovery data. North American herons winter from Canada through northern South America but especially in eastern North America south of New York, Florida, California, Louisiana, Texas, Mexico and Cuba, these areas accounting for 63% of winter recoveries. We identified regions where recoveries for various species clustered as "key areas." These forty-three areas constitute a network of areas that hold sites that likely are important to wintering North American herons. Within each area, we identify specific sites that are potentially important to wintering herons. The relative importance of each area and site within the network must be evaluated by further on the ground inventory. Because of biases inherent in the available data, these hypothesized key areas are indicative rather than exhaustive. As a first cut, this network of areas can serve to inform further inventory activities and can provide an initial basis to begin planning for the year-round conservation of North American heron populations.
Mikuska, T.; Kushlan, J. A.; Hartley, S.
Changing number of Canada geese wintering in different regions of the Atlantic Flyway
During the past 40 years, profound changes have occurred in the number of Canada geese (Branta canadensis) wintering in different regions of the Atlantic Flyway. To explain the declining number of wintering geese in the Chesapeake and Carolina regions and the increasing number in the mid-Atlantic region from 1984 to 1989, I tested several hypotheses concerning regional differences in production, survival, and movement. The observation of migratory geese neckbanded in northern Quebec and throughout the winter grounds, and the lack of a regional difference in the proportion of young in the harvest, indicated that regional differences in production on the breeding grounds was unlikely to explain the observed changes in mid-winter number. Average annual survival rates were highest for geese in the Chesapeake and lowest for geese in the mid-Atlantic indicating that differential survival between regions did not cause the large changes in mid-winter numbers between regions. Geese were more likely to move to, and remain in, the Chesapeake than any other region. Estimated movement patterns did not match observed changes in mid-winter counts. Consequently, the observed changes in number of wintering geese from 1984 to 1989 could not be explained by my analyses of differential production, survival, or movement. The survival and movement analyses, however, were based largely on data from migratory, northern breeding geese. In the aerial Midwinter Waterfowl Survey, migratory, northern-breeding geese cannot be distinguished from local, southern-breeding geese. The changes in mid-winter numbers may result from declining numbers of migratory, northern-breeding geese wintering in the Chesapeake and Carolinas and increasing numbers of local, southem-breeding geese remaining in the mid-Atlantic.
Hestbeck, J.B.
Winter Survival of Individual Honey Bees and Honey Bee Colonies Depends on Level of Varroa destructor Infestation
Background Recent elevated winter loss of honey bee colonies is a major concern. The presence of the mite Varroa destructor in colonies places an important pressure on bee health. V. destructor shortens the lifespan of individual bees, while long lifespan during winter is a primary requirement to survive until the next spring. We investigated in two subsequent years the effects of different levels of V. destructor infestation during the transition from short-lived summer bees to long-lived winter bees on the lifespan of individual bees and the survival of bee colonies during winter. Colonies treated earlier in the season to reduce V. destructor infestation during the development of winter bees were expected to have longer bee lifespan and higher colony survival after winter. Methodology/Principal Findings Mite infestation was reduced using acaricide treatments during different months (July, August, September, or not treated). We found that the number of capped brood cells decreased drastically between August and November, while at the same time, the lifespan of the bees (marked cohorts) increased indicating the transition to winter bees. Low V. destructor infestation levels before and during the transition to winter bees resulted in an increase in lifespan of bees and higher colony survival compared to colonies that were not treated and that had higher infestation levels. A variety of stress-related factors could have contributed to the variation in longevity and winter survival that we found between years. Conclusions/Significance This study contributes to theory about the multiple causes for the recent elevated colony losses in honey bees. Our study shows the correlation between long lifespan of winter bees and colony loss in spring. Moreover, we show that colonies treated earlier in the season had reduced V. destructor infestation during the development of winter bees resulting in longer bee lifespan and higher colony survival after winter.
van Dooremalen, Coby; Gerritsen, Lonne; Cornelissen, Bram; van der Steen, Jozef J. M.; van Langevelde, Frank; Blacquiere, Tjeerd
Decadal anomalies of winter precipitation over southern China in association with El Ni�o and La Ni�a
NASA Astrophysics Data System (ADS)
Using multiple datasets, this paper analyzes the characteristics of winter precipitation over southern China and its association with warm and cold phases of El Ni�o-Southern Oscillation during 1948-2011. The study proves that El Ni�o is an important external forcing factor resulting in above-normal winter precipitation in southern China. The study also reveals that the impact of La Ni�a on the winter precipitation in southern China has a decadal variability. During the winter of La Ni�a before 1980, the East Asian winter monsoon is stronger than normal with a deeper trough over East Asia, and the western Pacific subtropical high weakens with its high ridge retreating more eastward. Therefore, anomalous northerly winds dominate over southern China, leading to a cold and dry winter. During La Ni�a winter after 1980, however, the East Asian trough is weaker than normal, unfavorable for the southward invasion of the winter monsoon. The India-Burma trough is intensified, and the anomalous low-level cyclone excited by La Ni�a is located to the west of the Philippines. Therefore, anomalous easterly winds prevail over southern China, which increases moisture flux from the tropical oceans to southern China. Meanwhile, La Ni�a after 1980 may lead to an enhanced and more northward subtropical westerly jet over East Asia in winter. Since southern China is rightly located on the right side of the jet entrance region, anomalous ascending motion dominates there through the secondary vertical circulation, favoring more winter precipitation in southern China. Therefore, a cold and wet winter, sometimes with snowy and icy weathers, would occur in southern China during La Ni�a winter after 1980. Further analyses indicate that the change in the spatial distribution of sea surface temperature anomaly during the La Ni�a mature phase, as well as the decadal variation of the Northern Hemisphere atmospheric circulation, would be the important reasons for the decadal variability of the La Ni�a impact on the atmospheric circulation in East Asia and winter precipitation over southern China after 1980.
Yuan, Yuan; Li, Chongyin; Yang, Song
El Ni�o-Southern Oscillation Impacts on Winter Vegetable Production in Florida*.
NASA Astrophysics Data System (ADS)
Florida's mild winters allow the state to play a vital role in supplying fresh vegetables for U.S. consumers. Producers also benefit from premium prices when low temperatures prevent production in most of the country. This study characterizes the influence of the El Ni�o-Southern Oscillation (ENSO) on the Florida vegetable industry using statistical analysis of the response of historical crop (yield, prices, production, and value) and weather variables (freeze hazard, temperatures, rainfall, and solar radiation) to ENSO phase and its interaction with location and time of year. Annual mean yields showed little evidence of response to ENSO phase and its interaction with location. ENSO phase and season interacted to influence quarterly yields, prices, production, and value. Yields (tomato, bell pepper, sweet corn, and snap bean) were lower and prices (bell pepper and snap bean) were higher in El Ni�o than in neutral or La Ni�a winters. Production and value of tomatoes were higher in La Ni�a winters. The yield response can be explained by increased rainfall, reduced daily maximum temperatures, and reduced solar radiation in El Ni�o winters. Yield and production of winter vegetables appeared to be less responsive to ENSO phase after 1980; for tomato and bell pepper, this may be due to improvements in production technology that mitigate problems associated with excess rainfall. Winter yield and price responses to El Ni�o events have important implications for both producers and consumers of winter vegetables, and suggest opportunities for further research.
Hansen, James W.; Jones, James W.; Kiker, Clyde F.; Hodges, Alan W.
Temperature characteristics of winter roost-sites for birds and mammals: tree cavities and anthropogenic alternatives
NASA Astrophysics Data System (ADS)
The microclimate of potential roost-sites is likely to be a crucial determinant in the optimal roost-site selection of endotherms, in particular during the winter season of temperate zones. Available roost-sites for birds and mammals in European high trunk orchards are mainly tree cavities, wood stacks and artificial nest boxes. However, little is known about the microclimatic patterns inside cavities and thermal advantages of using these winter roost-sites. Here, we simultaneously investigate the thermal patterns of winter roost-sites in relation to winter ambient temperature and their insulation capacity. While tree cavities and wood stacks strongly buffered the daily cycle of temperature changes, nest boxes showed low buffering capacity. The buffering effect of tree cavities was stronger at extreme ambient temperatures compared to temperatures around zero. Heat sources inside roosts amplified ? T (i.e., the difference between inside and outside temperatures), particularly in the closed roosts of nest boxes and tree cavities, and less in the open wood stacks with stronger circulation of air. Positive ? T due to the installation of a heat source increased in cold ambient temperatures. These results suggest that orchard habitats in winter show a spatiotemporal mosaic of sites providing different thermal benefits varying over time and in relation to ambient temperatures. At cold temperatures tree cavities provide significantly higher thermal benefits than nest boxes or wood stacks. Thus, in winter ecology of hole-using endotherms, the availability of tree cavities may be an important characteristic of winter habitat quality.
Gr�ebler, Martin U.; Widmer, Silv; Korner-Nievergelt, Fr�nzi; Naef-Daenzer, Beat
Temperature characteristics of winter roost-sites for birds and mammals: tree cavities and anthropogenic alternatives.
The microclimate of potential roost-sites is likely to be a crucial determinant in the optimal roost-site selection of endotherms, in particular during the winter season of temperate zones. Available roost-sites for birds and mammals in European high trunk orchards are mainly tree cavities, wood stacks and artificial nest boxes. However, little is known about the microclimatic patterns inside cavities and thermal advantages of using these winter roost-sites. Here, we simultaneously investigate the thermal patterns of winter roost-sites in relation to winter ambient temperature and their insulation capacity. While tree cavities and wood stacks strongly buffered the daily cycle of temperature changes, nest boxes showed low buffering capacity. The buffering effect of tree cavities was stronger at extreme ambient temperatures compared to temperatures around zero. Heat sources inside roosts amplified ? T (i.e., the difference between inside and outside temperatures), particularly in the closed roosts of nest boxes and tree cavities, and less in the open wood stacks with stronger circulation of air. Positive ? T due to the installation of a heat source increased in cold ambient temperatures. These results suggest that orchard habitats in winter show a spatiotemporal mosaic of sites providing different thermal benefits varying over time and in relation to ambient temperatures. At cold temperatures tree cavities provide significantly higher thermal benefits than nest boxes or wood stacks. Thus, in winter ecology of hole-using endotherms, the availability of tree cavities may be an important characteristic of winter habitat quality. PMID:23423627
Gr�ebler, Martin U; Widmer, Silv; Korner-Nievergelt, Fr�nzi; Naef-Daenzer, Beat
Are summit metabolism and thermogenic endurance correlated in winter-acclimatized passerine birds?
Small birds exhibiting marked winter improvement of cold tolerance also show elevated summit metabolic rates (maximum cold-induced metabolic rate) in winter relative to summer. However, relatively large increases in cold tolerance can occur with only minor increments of maximum cold-induced metabolic rate and geographic variation in cold tolerance is not always positively correlated with variation in maximum cold-induced metabolic rate.
David L. Swanson
Winter lightning on Japan sea coast; Lightning striking frequency to tall structures
The nature of lightning striking tall structures on Japan sea coast in winter has been observed with automatically triggered camera and current measurements. The frequency of winter lightning striking tall structures is much higher than that of summer lightning and it increases proportionally to the height of structures. Sometimes lightning strikes simultaneously to multiple tall structures. Statistics of the striking frequency, striking angle and the leader length of the lightning discharge are presented.
Miyake, K.; Suzuki, T. (Central Research Inst. of Electric Power Industry, Tokyo (Japan)); Takashima, M. (Hokuriku Electric Power Co., Inc., Toyama (Japan)); Takuma, M. (Tokyo Electric Power Co., Chiyoda, Tokyo (JP)); Tada, T. (Sankosha Co., Sagamihara, Kanagawa (JP))
Variability of Winter Air Temperature in Mid-Latitude Europe
NASA Technical Reports Server (NTRS)
The aim of this paper is to report extreme winter/early-spring air temperature (hereinafter temperature) anomalies in mid-latitude Europe, and to discuss the underlying forcing to these interannual fluctuations. Warm advection from the North Atlantic in late winter controls the surface-air temperature, as indicated by the substantial correlation between the speed of the surface southwesterlies over the eastern North Atlantic (quantified by a specific Index Ina) and the 2-meter level air temperatures (hereinafter Ts) over Europe, 45-60 deg N, in winter. In mid-March and subsequently, the correlation drops drastically (quite often it is negative). This change in the relationship between Ts and Ina marks a transition in the control of the surface-air temperature: absorption of insolation replaces the warm advection as the dominant control. This forcing by maritime-air advection in winter was demonstrated in a previous publication, and is re-examined here in conjunction with extreme fluctuations of temperatures in Europe. We analyze here the interannual variability at its extreme by comparing warm-winter/early-spring of 1989/90 with the opposite scenario in 1995/96. For these two December-to-March periods the differences in the monthly mean temperature in Warsaw and Torun, Poland, range above 10 C. Short-term (shorter than a month) fluctuations of the temperature are likewise very strong. We conduct pentad-by-pentad analysis of the surface-maximum air temperature (hereinafter Tmax), in a selected location, examining the dependence on Ina. The increased cloudiness and higher amounts of total precipitable water, corollary effects to the warm low-level advection. in the 1989/90 winter, enhance the positive temperature anomalies. The analysis of the ocean surface winds is based on the Special Sensor Microwave/Imager (SSM/I) dataset; ascent rates, and over land wind data are from the European Centre for Medium-Range Weather Forecasts (ECMWF); maps of 2-m temperature, cloud cover and precipitable water are from the National Centers for Environmental Prediction (NCEP) Reanalysis.
Otterman, J.; Ardizzone, J.; Atlas, R.; Bungato, D.; Cierniewski, J.; Jusem, J. C.; Przybylak, R.; Schubert, S.; Starr, D.; Walczewski, J.
Expansion of penduline tit ( Remiz pendulinus ) through migration and wintering
Summary The migration and wintering ofRemiz pendulinus in western Europe is updated by analyzing the recoveries available in EURING Data Bank until 1990. The settlement of new winter quarters, the origin of the populations wintering in the Iberian peninsula and the westward shift in the winter and breeding areas, the latter spreading one season slower than the former, are assessed.
Francisco Valera; Pedro Rey; Alfonso M. Sanchez-Lafuente; Joaquin Mufioz-Cobo
Comparison of snowpack and winter wet-deposition chemistry in the Rocky Mountains, USA: Implications for winter dry deposition
Depth-integrated snowpack chemistry was measured just prior to maximum snowpack depth during the winters of 1992-1999 at 12 sites co-located with National Atmospheric Deposition Program/National Trend Network (NADP/NTN) sites in the central and southern Rocky Mountains, USA. Winter volume-weighted mean wet-deposition concentrations were calculated for the NADP/NTN sites, and the data were compared to snowpack concentrations using the paired t-test and the Wilcoxon signed-rank test. No statistically significant differences were indicated in concentrations of SO42- or NO3- (p>0.1). Small, but statistically significant differences (p???0.03) were indicated for all other solutes analyzed. Differences were largest for Ca2+ concentrations, which on average were 2.3??eql-1 (43%) higher in the snowpack than in winter NADP/NTN samples. Eolian carbonate dust appeared to influence snowpack chemistry through both wet and dry deposition, and the effect increased from north to south. Dry deposition of eolian carbonates was estimated to have neutralized an average of 6.9??eql-1 and a maximum of 12??eql-1 of snowpack acidity at the southernmost sites. The good agreement between snowpack and winter NADP/NTN SO42- and NO3- concentrations indicates that for those solutes the two data sets can be combined to increase data density in high-elevation areas, where few NADP/NTN sites exist. This combination of data sets will allow for better estimates of atmospheric deposition of SO42- and NO3- across the Rocky Mountain region.
Clow, D. W.; Ingersoll, G. P.; Mast, M. A.; Turk, J. T.; Campbell, D. H.
Multistate proteomics analysis reveals novel strategies used by a hibernator to precondition the heart and conserve ATP for winter heterothermy.
The hibernator's heart functions continuously and avoids damage across the wide temperature range of winter heterothermy. To define the molecular basis of this phenotype, we quantified proteomic changes in the 13-lined ground squirrel heart among eight distinct physiological states encompassing the hibernator's year. Unsupervised clustering revealed a prominent seasonal separation between the summer homeotherms and winter heterotherms, whereas within-season state separation was limited. Further, animals torpid in the fall were intermediate to summer and winter, consistent with the transitional nature of this phase. A seasonal analysis revealed that the relative abundances of protein spots were mainly winter-increased. The winter-elevated proteins were involved in fatty acid catabolism and protein folding, whereas the winter-depleted proteins included those that degrade branched-chain amino acids. To identify further state-dependent changes, protein spots were re-evaluated with respect to specific physiological state, confirming the predominance of seasonal differences. Additionally, chaperone and heat shock proteins increased in winter, including HSPA4, HSPB6, and HSP90AB1, which have known roles in protecting against ischemia-reperfusion injury and apoptosis. The most significant and greatest fold change observed was a disappearance of phospho-cofilin 2 at low body temperature, likely a strategy to preserve ATP. The robust summer-to-winter seasonal proteomic shift implies that a winter-protected state is orchestrated before prolonged torpor ensues. Additionally, the general preservation of the proteome during winter hibernation and an increase of stress response proteins, together with dephosphorylation of cofilin 2, highlight the importance of ATP-conserving mechanisms for winter cardioprotection. PMID:21914784
Grabek, Katharine R; Karimpour-Fard, Anis; Epperson, L Elaine; Hindle, Allyson; Hunter, Lawrence E; Martin, Sandra L
Summer Hot Snaps and Winter Conditions: Modelling White Syndrome Outbreaks on Great Barrier Reef Corals
Coral reefs are under increasing pressure in a changing climate, one such threat being more frequent and destructive outbreaks of coral diseases. Thermal stress from rising temperatures has been implicated as a causal factor in disease outbreaks observed on the Great Barrier Reef, Australia, and elsewhere in the world. Here, we examine seasonal effects of satellite-derived temperature on the abundance of coral diseases known as white syndromes on the Great Barrier Reef, considering both warm stress during summer and deviations from mean temperatures during the preceding winter. We found a high correlation (r2?=?0.953) between summer warm thermal anomalies (Hot Snap) and disease abundance during outbreak events. Inclusion of thermal conditions during the preceding winter revealed that a significant reduction in disease outbreaks occurred following especially cold winters (Cold Snap), potentially related to a reduction in pathogen loading. Furthermore, mild winters (i.e., neither excessively cool nor warm) frequently preceded disease outbreaks. In contrast, disease outbreaks did not typically occur following warm winters, potentially because of increased disease resistance of the coral host. Understanding the balance between the effects of warm and cold winters on disease outbreak will be important in a warming climate. Combining the influence of winter and summer thermal effects resulted in an algorithm that yields both a Seasonal Outlook of disease risk at the conclusion of winter and near real-time monitoring of Outbreak Risk during summer. This satellite-derived system can provide coral reef managers with an assessment of risk three-to-six months in advance of the summer season that can then be refined using near-real-time summer observations. This system can enhance the capacity of managers to prepare for and respond to possible disease outbreaks and focus research efforts to increase understanding of environmental impacts on coral disease in this era of rapidly changing climate.
Heron, Scott F.; Willis, Bette L.; Skirving, William J.; Eakin, C. Mark; Page, Cathie A.; Miller, Ian R.
Summer hot snaps and winter conditions: modelling white syndrome outbreaks on Great Barrier Reef corals.
Coral reefs are under increasing pressure in a changing climate, one such threat being more frequent and destructive outbreaks of coral diseases. Thermal stress from rising temperatures has been implicated as a causal factor in disease outbreaks observed on the Great Barrier Reef, Australia, and elsewhere in the world. Here, we examine seasonal effects of satellite-derived temperature on the abundance of coral diseases known as white syndromes on the Great Barrier Reef, considering both warm stress during summer and deviations from mean temperatures during the preceding winter. We found a high correlation (r(2) = 0.953) between summer warm thermal anomalies (Hot Snap) and disease abundance during outbreak events. Inclusion of thermal conditions during the preceding winter revealed that a significant reduction in disease outbreaks occurred following especially cold winters (Cold Snap), potentially related to a reduction in pathogen loading. Furthermore, mild winters (i.e., neither excessively cool nor warm) frequently preceded disease outbreaks. In contrast, disease outbreaks did not typically occur following warm winters, potentially because of increased disease resistance of the coral host. Understanding the balance between the effects of warm and cold winters on disease outbreak will be important in a warming climate. Combining the influence of winter and summer thermal effects resulted in an algorithm that yields both a Seasonal Outlook of disease risk at the conclusion of winter and near real-time monitoring of Outbreak Risk during summer. This satellite-derived system can provide coral reef managers with an assessment of risk three-to-six months in advance of the summer season that can then be refined using near-real-time summer observations. This system can enhance the capacity of managers to prepare for and respond to possible disease outbreaks and focus research efforts to increase understanding of environmental impacts on coral disease in this era of rapidly changing climate. PMID:20808912
Heron, Scott F; Willis, Bette L; Skirving, William J; Eakin, C Mark; Page, Cathie A; Miller, Ian R
Development of hard white winter wheats for a hard red winter wheat region
Hard white winter wheat (HWWW) occupies a very limited area of the USA, but its purported advantages suggest that its production in the major hard red winter wheat (HRWW) region may be feasible. Objectives of our investigations were to develop experimental HWWW lines that combined desirable attributes-grain yield, functional grain quality, and resistance to preharvest sprouting-in single genotypes for comparison
M. P. Upadhyay; G. M. Paulsen; E. G. Heyne; R. G. Sears; R. C. Hoseney
Flavor Characterization of Breads Made from Hard Red Winter Wheat and Hard White Winter Wheat
Cereal Chem. 69(5):556-559 Sensory flavor profiles for white pan bread and whole wheat bread impression than did HRW crust. HRW crumb was sweeter and more made from hard red winter (HRW) or hard white winter (HWW) wheat dairylike than HWW crumb. HWW crumb had a phenoliclike note not were developed by a professionally trained panel. The flavors of crust present
Distribution of Alewives in Southeastern Lake Ontario in Autumn and Winter: A Clue to Winter Mortalities
Alewives Alosa pseudoharengus in the Great Lakes are thought to avoid extreme cold in winter by moving to deep water where the temperature is usually highest because of inverse thermal stratification. Information collected in Lake Ontario during autumn and winter 1981�1984 with an echo sounder and bottom and midwater trawls indicated that many alewives remained at depths above 110 m,
Roger A. Bergstedt; Robert OGorman
Key areas for wintering North American herons
Nearly all North American heron populations are migratory, but details of where they winter are little known. Locations where North American herons winter were identified using banding recovery data. North American herons winter from Canada through northern South America but especially in eastern North America south of New York, Florida, California, Louisiana, Texas, Mexico and Cuba, these areas accounting for 63% of winter recoveries. We identified regions where recoveries for various species clustered as 'key areas.' These forty-three areas constitute a network of areas that hold sites that likely are important to wintering herons. The relative importance of each area and site within the network must be evaluated by further on the ground inventory. Because of biases inherent in the available data, these hypothesized key areas are indicative rather than exhaustive. As a first cut, this network of areas can serve to inform further inventory activities and can provide an initial basis to begin planning for the year-round conservation of North American heron populations.
Mikuska, T.; Kushlan, J.A.; Hartley, S.
Links between solar wind variations, the global electric circuit, and winter cyclone vorticity, and possibly to cold winters in Europe
NASA Astrophysics Data System (ADS)
There are a number of inputs to the atmosphere and the climate system that are modulated by solar activity that have their only common feature the modulation of the ionosphere-earth current density (Jz) in the global electric circuit, and to which it has now been shown there are small atmospheric responses in winter storm vorticity, surface pressure, and cloud cover. Similar responses are found to internal atmospheric inputs that modulate Jz. An inductive mechanism for initial storm electrification is described that responds to Jz and provides space charge for aerosol particles and droplets throughout the updraft region. The charge on droplets and aerosol particles, by the process of charge modulation of aerosol scavenging (CMAS), increases condensation nuclei concentrations and shifts their distributions to smaller average sizes. This produces smaller and more numerous droplets, and as shown by Rosenfeld et al (2008), delays initial precipitation and increases ice production and the vigor of the storm updraft. For baroclinic storms the additional latent heat release and updraft velocity increases storm vorticity. The result depends on both aerosol characteristics and the Jz variation. The cumulative effect of winter storm intensification, for example in the Icelandic Low cyclogenesis region, responding to Jz changes, is to increase blocking in the Atlantic Ocean. Such blocking reduces the flow of relatively warm moist ocean air onto Europe, while increasing the incidence of outbreaks of cold, dry, Arctic air. The possibility is examined that increases in cosmic ray flux and in Jz, at times of decadal and longer minima in solar activity, contributes to the changes in atmospheric circulation and the resulting unusually severe winters in the UK and Europe such as have occurred during extended solar minima in the late 17th century and early 21st century.
Tinsley, B. A.
Interdecadal and Interannual Variability of Winter Precipitation in Southeast China
NASA Astrophysics Data System (ADS)
Interdecadal variability of observed winter (DJF) precipitation in Southeast China (1961 to 2010) is characterized by the first EOF of the three-monthly Standardized Precipitation Index (SPI) subjected to a 9-year running mean, while the differences from the original describe the interannual fluctuations. For interdecadal time scales the dominating spatial modes represent monopole features over Southeast China involving the Arctic Oscillation (AO) and the sea surface temperature (SST) anomalies over western Pacific. Dynamic composite analysis (based on NCEP/NCAR and ERA-40 reanalyzes) reveals the following results: (i) Interdecadal SPI-variations show a trend from a dryer state in the 1970s via an increase during the 1980s towards stabilization of wetter conditions commencing with the 1990s. (ii) In mid-to-high latitudes the weakened southward flow of polar airmasses induces low-level warming over Eurasia due to stronger Arctic Oscillation (AO) by warmer zonal temperature advection. This indicates that the precipitation increase in Southeast is attributed circulation anomalies over mid-to-high latitudes which are related to AO. (iii) The abnormal moisture flux along the southwestern boundary of the abnormal anticyclone over south Japan (and its anomalous south-easterlies) is modulated by the sea surface temperature (SST) anomalies over Western Pacific; a positive (negative) SST anomaly will strengthen (weaken) the warm and moist air flow, leading to abundant (less) precipitation in Southeast China. This demonstrates the collaborative effect of AO and SST anomalies in determining the nonlinear trend observed in winter precipitation over Southeast China. For interannual time scales the dominating spatial pattern also represents monopole patterns. Composite analysis (with resampling test) of the associated circulation anomalies reveals the following results: (i) The wet (dry) winter is a result of the strengthened (weakened) northward warm moist air over east coast of China, which is caused by the weakened (strengthened) East Asian Winter Monsoon (EAWM) due to weakening (strengthening) of Siberia High (SH) and eastward (westward) extending of East Asian Trough (EAT). (ii) The effects of El Ni�o and sea surface temperature (SST) anomalies over South China Sea (SCS) on rainfall in Southeast China are independent. El Ni�o years, the anomalous anticyclone (cyclone) over Philippines leads to positive (negative) anomalies of rainfall over South China, while in years with the anomalous positive (negative) SST over SCS (non-ENSO), more (less) water vapor is conveyed to Southeast China, thereby enhancing (reducing) precipitation over south of the Yangtze River. (iii) Contributions from all impact factors (EAWM, SH, EAT, El Ni�o events and SST SCS anomalies) do not counteract with one aother to generate the Southeast China winter precipitation variability.
Zhang, L.; Fraedrich, K.; Zhu, X.; Sielmann, F.
A Rocky Mountain Storm. Part I: The Blizzard�Kinematic Evolution and the Potential for High-Resolution Numerical Forecasting of Snowfall
Over the 3-day period of 24-26 October 1997, a powerful winter storm was the cause of two exceptional weather phenomena: 1) blizzard conditions from Wyoming to southern New Mexico along the Front Range of the Rocky Mountains and 2) hurricane-force winds at the surface near Steamboat Springs, Colorado, with the destruction of about 5300 ha of old-growth forest. This rare
Gregory S. Poulos; Douglas A. Wesley; John S. Snook; Michael P. Meyers
Climate Change Impacts on Winter and Spring Runoff and Recharge in Wisconsin
NASA Astrophysics Data System (ADS)
Our research seeks to quantify the impacts of warming winter temperatures and increased winter precipitation on water resources in Wisconsin. We are currently working to calibrate a Precipitation-Runoff Modeling System (PRMS) model of the Black Earth Creek Watershed, and will be using a newly-created frost module to examine the impacts of warming winter temperatures on winter and spring infiltration. As a class 1 trout stream, Black Earth Creek is of particular interest as a sensitive and economically important natural resource. Research carried out over 2010 utilized a one-dimensional soil model (Simultaneous Heat and Water, or SHAW) that simulates heat and water fluxes as well as frost processes. This model was driven by climate data obtained from a set of statistically-downscaled and de-biased General Circulation Model (GCM) data for historic and projected future for the years 2046-2065 and 2081-2100 under the SRES A1B emissions scenario. This research suggested that warming temperatures and reduced snow cover, along with a projected increase in winter precipitation, would lead to decreased soil frost formation and a commensurate increase in winter and spring infiltration and recharge. The one-dimensional structure of the model, however, made it difficult to calibrate at the landscape scale, as it is fundamentally unable to replicate the complex spatial processes that are critically important to hydrologic response. We hope that the PRMS model, driven with the same modeled climatic data, will be able to confirm the results of our SHAW modeling; namely that winter and spring recharge will increase significantly in a warming climate. Such an increase in recharge could have profound impacts on Wisconsin fisheries, agriculture, and development.
Murdock, E. A.; Potter, K. W.
Distribution of alewives in southeastern Lake Ontario in autumn and winter: a clue to winter mortalities
Alewives Alosa pseudoharengus in the Great Lakes are thought to avoid extreme cold in winter by moving to deep water where the temperature is usually highest because of inverse thermal stratification. Information collected in Lake Ontario during autumn and winter 1981-1984 with an echo sounder and bottom and midwater trawls indicated that many alewives remained at depths above 110 m, regardless of water temperature. Alewives in the Great Lakes that did not descend to greater depths would be exposed to potentially lethal temperatures during cold winters.
Bergstedt, Roger A.; O'Gorman, Robert
Improving winter river flow forecasts for the UK
NASA Astrophysics Data System (ADS)
Winter is the main season for recharge of groundwater and reservoirs in the United Kingdom (UK), and therefore influences the water availability during the rest of the year. Whereas hydrological predictions on timescales of days are comparatively successful, predictability on a seasonal scale is still limited and is mainly a result of the strong dependence of the flow on initial water storage conditions in the catchments. Seasonal river flow and groundwater predictions on a national, year-round scale have recently become available for the UK through the Hydrological Outlooks (http://www.hydoutuk.net/). For winter (December to February) mean river flows, these forecasts tend to be less skilful in the northwest than the southeast. Here we demonstrate new methodologies which take advantage of the remarkable geographical complementarity between the regional geological variations and regional meteorology, enabling increased skill in long range forecasts of winter river flows across the UK. Forecasts made at the start of winter show significant skill, which derives mainly from the geological memory of antecedent conditions in southern and eastern parts of the UK and from greater long range predictability of seasonal rainfall in northern and western areas of the UK. Many river catchments in lowland (southern and eastern) UK have a permeable geology and therefore a runoff regime dominated by slowly released groundwater. In contrast, catchments in the northwest are generally less permeable and therefore faster responding to rainfall events, making good seasonal rainfall forecasts essential for successful river flow forecasts. Winter rainfall in this region is primarily controlled by the North Atlantic Oscillation (NAO), and forecast methods are presented which take advantage of recent improvements in the predictability of the sea level pressure field over the North Atlantic by the GloSea5 seasonal climate prediction system. Two river flow forecast methods are presented. The first consists of at-site linear regression forecasts using the preceding November's river flow and the December-February forecast of the NAO index as predictors. Second, a grid-based hydrological model is run using NAO-adjusted rainfall forecasts from GloSea5 as input. These rainfall forecasts lead to improved river flow forecasts in the northwest compared to using non-adjusted rainfall forecasts. Results for groundwater modelling are mixed, partly because most aquifers are located in the south and east rather than the northwest, and are therefore less affected by the NAO. But the slow response times of groundwater stores also mean that the resulting groundwater levels are complex aggregates of rainfall, evaporation and soil moisture over a longer time period than just the forecast period.
Svensson, Cecilia; Bell, Victoria A.; Brookshaw, Anca; Scaife, Adam A.; Mackay, Jonathan D.; Jackson, Christopher R.; Arribas, Alberto; Williams, Andrew
Clouds in the Winter Arctic Tropopause Region
NASA Technical Reports Server (NTRS)
Water vapor in the winter arctic tropopause region is important because, after the tropical tropopause region, the winter arctic tropopause has the coldest temperatures in the tropospheric northern hemisphere. This suggests the potential for cloud formation that can remove water vapor from a part of the atmosphere where radiatively active gases (such as water) exert a disproportionate influence on the earth's radiation budget. Previous work by the same authors has shown that this cloud formation extends into the stratosphere, with 20% of the parcels having ozone values of 300-350 ppbv experiencing ice saturation in any given 10 day period period during the late winter. In fact, temperatures are cold enough that 5-10% of the parcels experience saturation even if the water content is below the prevailing stratospheric value of 5 ppmv. This work describes a case study of clouds observed by aircraft near the winter arctic tropopause during the SAGE Ozone Loss and Validation Experiment (SOLVE). This provided a unique opportunity to examine dehydration processes in this region since in situ water, tracer, cloud particle, and meteorological data were all available simultaneously. During this period, temperatures were cold enough at the tropopause to produce saturation mixing ratios of 3-4 ppmv. Thus, clouds were actually observed within the stratosphere. Back trajectories indicate that the air in these clouds came from lower latitudes and altitudes. The study describes the nature of the clouds, the history of the air, and the possible implications for the upper tropospheric water budget.
Pfister, Leonhard; Selkirk, Henry; Anderson, Bruce; Podolske, James; Sachse, Glen; Avery, Melody; Schoeberl, Mark; Hipskind, R. Stephen (Technical Monitor)
Crude Oil Behavior on Arctic Winter Ice.
National Technical Information Service (NTIS)
Oil spill behavior in an Arctic winter environment is investigated. Several small controlled oil spills were conducted on the Bering Sea in Northwestern Alaska. To duplicate a real world spill as closely as possible, a Prudhoe Bay crude oil was used as th...
T. J. McMinn
Overview of climatic effects of nuclear winter
A general description of the climatic effects of a nuclear war are presented. This paper offers a short history of the subject, a discussion of relevant parameters and physical processes, and a description of plausible nuclear winter scenario. 9 refs. (ACR)
Jones, E.M.; Malone, R.C.
Soviet Exploitation of the 'Nuclear Winter' Hypothesis.
National Technical Information Service (NTIS)
This study, which is based entirely on open Soviet sources, examines and analyzes Soviet views on and uses made by Soviet scientists of the so-called ''Nuclear Winter'' hypothesis. In particular, the study seeks to ascertain whether Soviet scientists have...
L. Goure
Outing Activities and Winter Sports Guide.
ERIC Educational Resources Information Center
This guide contains articles on outdoor recreational activities and official winter sports rules for girls and women. The articles on outdoor activities include the techniques, teaching, and organization of camping, canoeing, competitive cycling, and riflery. Four pages of references on nature and outdoor activities are presented along with two�
Knierim, Helen, Ed.; Hobson, Barbara B., Ed.
Appalachia's Winter Secret: Downhill on the Mountains.
ERIC Educational Resources Information Center
Describes ski-industry and winter-tourism growth in Appalachia. Sketches ski-resort developments in Maryland, Pennsylvania, North Carolina, and West Virginia. Describes economic threats to industry, its economic impact on Appalachian states and region, resorts' general qualities, and ski industry's promotional efforts. (TES)
Johnson, Randy
Music Activities for Lemonade in Winter
ERIC Educational Resources Information Center
"Lemonade in Winter: A Book About Two Kids Counting Money" is a children's book about math; however, when sharing it in the music classroom, street cries and clapping games emerge. Jenkins' and Karas' book provides a springboard to lessons addressing several music elements, including form, tempo, and rhythm, as well as�
Cardany, Audrey Berger
Winter crops classification using satellite data
A technique for winter crops classification using satellite data is suggested. The technique is based on textural measures computed using the gray level difference vector approach (GLDV). The present study compares classification results derived by visual analyses of an area from a low-flying plane and from the GLDV approach using satellite data. It was found that the GLDV approach produces
O. Kryvobok
Population Trends of Wintering Bats in Vermont
We report the results of all readily available inventories of wintering bats in Vermont. Surveys at 23 hibernacula were compiled from the literature and unpublished data of numerous biologists and cavers. The earliest Vermont records date back to 1934. Only five hibernacula were systematically surveyed for more than 45 years. Despite data limitations, several trends have emerged. Since the 1930s,
Stephen C. Trombulak; Philip E. Higuera; Mark DesMeules
Winter In Northern Europe (WINE) project
NASA Technical Reports Server (NTRS)
The scientific aims, work plan, and organization of the Middle Atmosphere Program winter in northern Europe (MAP/WINE) are described. Proposed contributions to the MAP/WINE program from various countries are enumerated. Specific atmospheric parameters to be examined are listed along with the corresponding measurement technique.
Vonzahn, U.
Nuclear winter - Physics and physical mechanisms
NASA Technical Reports Server (NTRS)
The basic physics of the environmental perturbations caused by multiple nuclear detonations is explored, summarizing current knowledge of the possible physical, chemical, and biological impacts of nuclear war. Emphasis is given to the impact of the bomb-generated smoke (soot) particles. General classes of models that have been used to simulate nuclear winter are examined, using specific models as examples.
Turco, R. P.; Toon, O. B.; Pollack, J. B.; Ackerman, T. P.; Sagan, C.
Extreme Winter Temperatures in Fairbanks, Alaska.
National Technical Information Service (NTIS)
A study was made of the ambient temperatures in Fairbanks, Alaska, during the winter months (November through March). Twenty-one years of records were used. The data included the period of the lowest officially recorded temperature. The temperature was se...
M. B. Gens
PLCO News, Fall/Winter 1998 Volume 2, Number 1 ----- Spring/Summer 1999 Trial Update Enrollment goal: 148,000 Total enrollment (as of March 15, 1999): 121,027 Men enrolled: 62,409 Women enrolled: 58,618 Number of people enrolled
The History of Winter: A Professional Development
Each year since 2000, the NASA Goddard History of Winter (HOW) program has allowed teachers to develop an understanding of the consequences of one segment of the orbit of the tilted Earth in its path around the sun. Scientists from NASA, CRREL, and Michigan Tech, supported by the Whiteface Observatory, and the science program at Northwood School in Lake Placid,
R. E. Gabrys
Sea Surface Temperatures and Australian Winter Rainfall
A rotated principal component analysis of Australian winter (June-August) rainfall revealed two large-scale patterns of variation which together accounted for more than half of the total rainfall variance. The first pattern was a broadband stretching from the northwest to the southeast corners of the country. The second was centered in the eastern third of the continent. The two patterns were
Neville Nicholls
Science of the Olympic Winter Games
NSDL National Science Digital Library
NBC Learn has teamed up with the National Science Foundation to produce Science of the Olympic Winter Games, a 16-part video series that explores the science behind individual Olympic events. Each video is complemented with lesson plans which include fun classroom activities.
PLCO News, Fall/Winter 1998 Volume 3, Number 1 ----- Spring/Summer 2000 Trial Update Enrollment goal: 148,000 Total enrollment (as of December 29, 1999): 138,847 Men enrolled: 69,990 Women enrolled: 68,857 Number of people enrolled
Winter Warming from Large Volcanic Eruptions.
National Technical Information Service (NTIS)
An examination of the Northern Hemisphere winter surface temperature patterns after the 12 largest volcanic eruptions from 1883-1992 shows warming over Eurasia and North America and cooling over the Middle East which are significant at the 95 percent leve...
A. Robock J. Mao
Winter Shamal in the Persian Gulf.
National Technical Information Service (NTIS)
Occurrence and air/sea effects of the winter shamal, a subsynoptic-scale wind phenomenon in the Persian Gulf region, are examined by means of a conceptual model which relates upper air and surface features to mesoscale weather events and conditions. Two c...
T. J. Perrone
Winter Wheat Fertilization: Post Ammonium Nitrate
Summary The potential for overwinter losses of nitrogen by denitrification and leaching have led to the recommendation that nitrogen fertilization of winter wheat be done using ammonium nitrate broadcast in the spring. However, spring broadcast application of urea can result in significant loss of nitrogen by volatilization and immobilization by surface residues. Since prilled ammonium nitrate is not available for
R. Byron Irvine; Guy Lafond; Randy Kutcher
Northern pintail body condition during wet and dry winters in the Sacramento Valley, California
Body weights and carcass composition of male and female adult northern pintails (Anas acuta) were investigated in the Sacramento Valley, California, from August to March 1979-82. Pintails were lightweight, lean, and had reduced breast, leg, and heart muscles during August-September. Ducks steadily gained weight after arrival; and body, carcass (body wt minus feathers and gastrointestinal content), fat protein, and muscle weights peaked in October-November. Fat-free dry weight remained high but variable the rest of the winter, whereas body and carcass weight and fat content declined to lows in December or January, then increased again in February or March. Gizzard weights declined from early fall to March. Males were always heavier than females, but females were fatter (percentage) than males during mid-winter. Mid-winter body weight, carcass fat, and protein content were significantly (P < 0.01) lower in the dry winter of 1980-81 than in 2 wet winters (1979-80 and 1981-82). Changes in pintail body weight and composition during winter are probably adaptations to mild climate, predictable food supplies, and requirements for pair formation and molt.
Miller, M. R.
Climate Change Affects Winter Chill for Temperate Fruit and Nut Trees
Background Temperate fruit and nut trees require adequate winter chill to produce economically viable yields. Global warming has the potential to reduce available winter chill and greatly impact crop yields. Methodology/Principal Findings We estimated winter chill for two past (1975 and 2000) and 18 future scenarios (mid and end 21st century; 3 Global Climate Models [GCMs]; 3 greenhouse gas emissions [GHG] scenarios). For 4,293 weather stations around the world and GCM projections, Safe Winter Chill (SWC), the amount of winter chill that is exceeded in 90% of all years, was estimated for all scenarios using the �Dynamic Model� and interpolated globally. We found that SWC ranged between 0 and about 170 Chill Portions (CP) for all climate scenarios, but that the global distribution varied across scenarios. Warm regions are likely to experience severe reductions in available winter chill, potentially threatening production there. In contrast, SWC in most temperate growing regions is likely to remain relatively unchanged, and cold regions may even see an increase in SWC. Climate change impacts on SWC differed quantitatively among GCMs and GHG scenarios, with the highest GHG leading to losses up to 40 CP in warm regions, compared to 20 CP for the lowest GHG. Conclusions/Significance The extent of projected changes in winter chill in many major growing regions of fruits and nuts indicates that growers of these commodities will likely experience problems in the future. Mitigation of climate change through reductions in greenhouse gas emissions can help reduce the impacts, however, adaption to changes will have to occur. To better prepare for likely impacts of climate change, efforts should be undertaken to breed tree cultivars for lower chilling requirements, to develop tools to cope with insufficient winter chill, and to better understand the temperature responses of tree crops.
Luedeling, Eike; Girvetz, Evan H.; Semenov, Mikhail A.; Brown, Patrick H.
Winter Ecology of the Western Burrowing Owl (Athene cunicularia hypugaea) in Southern Texas 1999-2004
This study examines the winter ecology of the western burrowing owl (Athene cunicularia hypugaea) in five Texas counties surrounding Corpus Christi, in southern Texas. There is a substantial gap in information on the owl's life cycle during migration and non-breeding winter months; almost all previous research on western burrowing owls has been conducted during the breeding season. The western burrowing owl currently is federally threatened in Mexico, federally endangered in Canada, and in the United States is considered a National Bird of Conservation Concern by the U.S. Fish and Wildlife Service. Topics investigated included status, effectiveness of public outreach, roost sites and use of culverts and artificial burrows, roost site fidelity, diet, contaminant burdens, body mass, and ectoparasites. Early ornithological reports and a museum egg set revealed that burrowing owls once bred in southern Texas and were common in winter; however, since the 1950's they have been reported in relatively low numbers and only during winter. In this study, public outreach increased western burrowing owl detections by 68 percent. Owls selected winter roost sites with small-diameter openings, including culverts less than or equal to 16 centimeters and artificial burrows of 15 centimeters, probably because the small diameters deterred mammalian predators. Owls showed strong roost site fidelity; 15 banded birds stayed at the same roost sites within a winter, and 8 returned to the same site the following winter. The winter diet was over 90 percent insects, with crickets the primary prey. Analyses of invertebrate prey and regurgitated pellets showed that residues of all but 3 of 28 carbamate and organophosphate pesticides were detected at least once, but all were below known lethal concentrations. Mean body mass of western burrowing owls was 168 grams and was highest in midwinter. Feather lice were detected in low numbers on a few owls, but no fleas or other ectoparasites were found.
Woodin, Marc C.; Skoruppa, Mary K.; Hickman, Graham C.
The long winter model of Martian biology - A speculation.
NASA Technical Reports Server (NTRS)
A temporal microenvironment model is proposed for Martian biology that is based on an estimated mean thickness of nearly 1 km of frost in the Martian north polar cap summer remnant. If vaporized, this frost could yield not only 1 kg per sq cm of atmosphere, but also higher global temperatures through the greenhouse effect and a greatly increased likelihood of liquid water. Vaporization of such cap remnants may occur twice each equinoctial precession, and Martian organisms may now be in cryptobiotic repose awaiting the end of the long precessional winter. The Viking biology experiments might test this hypothesis.
Sagan, C.
Nuclear Winter: The implications for civil defense
''Nuclear Winter'' is the term given to hypothesized cooling in the northern hemisphere following a nuclear war due to injection of smoke from burning cities into the atmosphere. The voluminous literature on this subject produced since the original paper in 1983 by Turco, Toon, Ackerman, Pollack, and Sagen (TTAPS) has been reviewed. The widespread use of 3-dimensional global circulation models have resulted in reduced estimates of cooling; 15 to 25/sup 0/C for a summer war and a few degrees for a winter war. More serious may be the possibility of suppression of convective precipitation by the altered temperature profiles in the atmosphere. However, very large uncertainties remain in input parameters, the models, and the results of calculations. We believe the state of knowledge about nuclear winter is sufficiently developed to conclude: Neither cold nor drought are likely to be direct threats to human survival for populations with the wherewithal to survive normal January temperatures; The principal threat from nuclear winter is to food production, and could present problems to third parties without food reserves; and Loss of a crop year is neither a new nor unexpected threat from nuclear war to the US and the Soviet Union. Both have at least a year's food reserve at all times. Both face formidable organizational problems in distributing their reserves in a war-damaged environment. The consequences of nuclear winter could be expected to fall more heavily on the Soviet Union than the US due to its higher latitude and less productive agriculture. This may be especially true if disturbances of rainfall amounts and distribution persist for more than a year. 6 refs.
Chester, C.V.; Perry, A.M.; Hobbs, B.F.
Space-time clustering of, and risk factors for, farmer-diagnosed winter dysentery in dairy cattle
We used two statistical techniques for space-time cluster analysis, the Knox and the Mantel regression methods, for an analysis of whether herd outbreaks of farmer-diagnosed winter dysentery during the winter of 1987-1988 were clustered in space and time more than would be expected by chance. Using the Knox method, there was significant space-time clustering of outbreaks of winter dysentery within a 30 day time and a 5.5 km radius. There was also significant space-time clustering by the Mantel regression method. Logistic regression was used to study risk factors for herd outbreaks of winter dysentery. Large herds (>60 cows) and herds with a history of an outbreak prior to 1987 had increased chances of an outbreak occurring in 1987-1988. These results are compatible with an infectious cause for winter dysentery. ImagesFigure 1.
White, Maurice E.; Schukken, Ynte Hein; Tanksley, Beth
Theoretical models of adaptive energy management in small wintering birds.
Many small passerines are resident in forests with very cold winters. Considering their size and the adverse conditions, this is a remarkable feat that requires optimal energy management in several respects, for example regulation of body fat reserves, food hoarding and night-time hypothermia. Besides their beneficial effect on survival, these behaviours also entail various costs. The scenario is complex with many potentially important factors, and this has made 'the little bird in winter' a popular topic for theoretic modellers. Many predictions could have been made intuitively, but models have been especially important when many factors interact. Predictions that hardly could have been made without models include: (i) the minimum mortality occurs at the fat level where the marginal values of starvation risk and predation risk are equal; (ii) starvation risk may also decrease when food requirement increases; (iii) mortality from starvation may correlate positively with fat reserves; (iv) the existence of food stores can increase fitness substantially even if the food is not eaten; (v) environmental changes may induce increases or decreases in the level of reserves depending on whether changes are temporary or permanent; and (vi) hoarding can also evolve under seemingly group-selectionistic conditions. PMID:17827099
Brodin, Anders
Effects of winter atmospheric circulation on temporal and spatial variability in annual streamflow in the western United States
Winter mean 700-hectoPascal (hPa) height anomalies, representing the average atmospheric circulation during the snow season, are compared with annual streamflow measured at 140 streamgauges in the western United States. Correlation and anomaly pattern analyses are used to identify relationships between winter mean atmospheric circulation and temporal and spatial variability in annual streamflow. Results indicate that variability in winter mean 700-Hpa height anomalies accounts for a statistically significant portion of the temporal variability in annual streamflow in the western United States. In general, above-average annual streamflow is associated with negative winter mean 700-Hpa height anomalies over the eastern North Pacific Ocean and/or the western United States. The anomalies produce an anomalous flow of moist air from the eastern North Pacific Ocean into the western United States that increases winter precipitation and snowpack accumulations, and subsequently streamflow. Winter mean 700-hPa height anomalies also account for statistically significant differences in spatial distributions of annual streamflow. As part of this study, winter mean atmospheric circulation patterns for the 40 years analysed were classified into five winter mean 700-hPa height anomaly patterns. These patterns are related to statistically significant and physically meaningful differences in spatial distributions of annual streamflow.
McCabe, Jr. , G. J.
Measurement of evapotranspiration in a winter wheat field
NASA Astrophysics Data System (ADS)
Daily evapotranspiration from a winter wheat field on the North China Plain measured by large-scale weighing lysimeter was linearly related to that measured by the Bowen ratio energy balance (BREB) technique. Soil evaporation averaged about 23�6% of evapotranspiration from the post-winter dormancy revival stage to the grain ripening stage in 1999. On clear days during winter dormancy, about half of the net radiation flux Rn was used to warm soil. During the revival stage, conductive heat flux G also used most of the incoming Rn, but the ratio of latent heat flux E to Rn increased. During the stem-extension stage, E was about 50% of Rn; thereafter, E/Rincreased continually, but Zhang, Yongqiang; Liu, Changming; Shen, Yanjun; Kondoh, A.; Tang, Changyuan; Tanaka, T.; Shimada, J. 2002-10-01
Zhang, Yongqiang; Liu, Changming; Shen, Yanjun; Kondoh, A.; Tang, Changyuan; Tanaka, T.; Shimada, J.
A Business Case for Winter Maintenance Technology Applications: Highway Maintenance Concept Vehicle
The purpose of this paper is to demonstrate, from a business perspective, the benefits of using technology applications in winter maintenance operations. This paper documents the business case to be made for the technology applications on the Highway Maintenance Concept Vehicle (HMCV) project by examining the business implications of many benefits such as increased safety, reduced environmental impacts, and increased
Dennis A. Kroeger; Reggie Sinhaa
Calcium addition at the Hubbard Brook Experimental Forest reduced winter injury to red spruce in a high-injury year
Laboratory experiments have verified that acid-deposition-induced calcium (Ca) leaching reduces the foliar cold tolerance of red spruce (Picea rubens Sarg.) current-year foliage, increasing the risk of winter injury and crown deterioration. However, to date no studies have shown that ambient losses in soil Ca have resulted in increased winter injury in the field. In 2003, a year of severe region-wide
Gary J. Hawley; Paul G. Schaberg; Christopher Eagar; Catherine H. Borer
Characteristics of foraging sites and protein status in wintering muskoxen: Insights from isotopes of nitrogen
Identifying links between nutritional condition of individuals and population trajectories greatly enhances our understanding of the ecology, conservation, and management of wildlife. For northern ungulates, the potential impacts of a changing climate to populations are predicted to be nutritionally mediated through an increase in the severity and variance in winter conditions. Foraging conditions and the availability of body protein as a store for reproduction in late winter may constrain productivity in northern ungulates, yet the link between characteristics of wintering habitats and protein status has not been established for a wild ungulate. We used a non-invasive proxy of protein status derived from isotopes of N in excreta to evaluate the influence of winter habitats on the protein status of muskoxen in three populations in Alaska (2005-2008). Multiple regression and an information-theoretic approach were used to compare models that evaluated the influence of population, year, and characteristics of foraging sites (components of diet and physiography) on protein status for groups of muskoxen. The observed variance in protein status among groups of muskoxen across populations and years was partially explained (45%) by local foraging conditions that affected forage availability. Protein status improved for groups of muskoxen as the amount of graminoids in the diet increased (-0.430 ?? 0.31, ???? 95% CI) and elevation of foraging sites decreased (0.824 ?? 0.67). Resources available for reproduction in muskoxen are highly dependent upon demographic, environmental, and physiographic constraints that affect forage availability in winter. Due to their very sedentary nature in winter, muskoxen are highly susceptible to localized foraging conditions; therefore, the spatial variance in resource availability may exert a strong effect on productivity. Consequently, there is a clear need to account for climate-topography effects in winter at multiple scales when predicting the potential impacts of climatic shifts on population trajectories of muskoxen. ?? 2011 The Authors.
Gustine, D. D.; Barboza, P. S.; Lawler, J. P.; Arthur, S. M.; Shults, B. S.; Persons, K.; Adams, L. G.
Understanding Utah Winter Storms: The Intermountain Precipitation Experiment.
NASA Astrophysics Data System (ADS)
other regions of the country because of the complex topography, the lack or limited utility of upstream and in situ data, and insufficient understanding of storm and precipitation processes.The Intermountain Precipitation Experiment (IPEX) is a research program designed to improve the understanding, analysis, and prediction of precipitation over the complex topography of the Intermountain West. The field phase of this research program was held in northern Utah in February 2000. During this time, seven storms were observed, including the heaviest snowfall to strike the Wasatch Mountains in two years, a tornadic bow echo associated with a strong cold front, a mesoscale snowband in Tooele Valley, and three other storms with locally heavy orographic snowfall and complex mesoscale circulations. Some of these storms were electrified and produced lightning.This paper reviews the weather of the Intermountain West, describes the experimental setup and the outreach activities of IPEX, and presents preliminary results from the field phase. Finally, lessons learned in planning and executing this field program are discussed.
Schultz, David M.; Steenburgh, W. James; Trapp, R. Jeffrey; Horel, John; Kingsmill, David E.; Dunn, Lawrence B.; Rust, W. David; Cheng, Linda; Bansemer, Aaron; Cox, Justin; Daugherty, John; Jorgensen, David P.; Meit�n, Jos�; Showell, Les; Smull, Bradley F.; Tarp, Keli; Trainor, Marilu
33 CFR 401.92 - Wintering and lying-up.
Code of Federal Regulations, 2010 CFR
... 3 2009-07-01 2009-07-01 false Wintering and lying-up. 401.92 Section 401.92 Navigation and Navigable...AND RULES Regulations General § 401.92 Wintering and lying-up. No vessel shall winter within the Seaway or...
33 CFR 401.92 - Wintering and lying-up.
Code of Federal Regulations, 2010 CFR
... 3 2010-07-01 2010-07-01 false Wintering and lying-up. 401.92 Section 401.92 Navigation and Navigable...AND RULES Regulations General § 401.92 Wintering and lying-up. No vessel shall winter within the Seaway or...
Sources and contributions of wood smoke during winter in London
NASA Astrophysics Data System (ADS)
Determining the contribution of wood smoke in large urban centres such as London is becoming increasingly important with the changing nature of domestic heating partly due to the installation of biomass burning heaters to meet renewable energy targets imposed by the EU and also a rise in so-called recreational burning for aesthetic reasons (Fuller et al., 2013). Recent work in large urban centres (London, Paris and Berlin) has demonstrated an increase in the contribution of wood smoke to ambient particles during winter that can at times exceed traffic emissions. In Europe, biomass burning has been identified as a major cause of exceedances of European air quality limits during winter (Fuller et al., 2013). In light of the changing nature of emissions in urban areas there is a need for on-going measurements to assess the impact of biomass burning in cities like London. Therefore we aimed to determine quantitatively the contribution of biomass burning in London and surrounding rural areas. We also aimed to determine whether local emissions or regional sources were the main source of biomass burning in London. Sources of wood smoke during winter in London were investigated at an urban background site (North Kensington) and two surrounding rural sites (Harwell and Detling) by analysing selected wood smoke chemical tracers. Concentrations of levoglucosan, elemental carbon (EC), organic carbon (OC) and K+ were generally well correlated, indicating a similar source of these species at the three sites. Based on the conversion factor for levoglucosan, mean wood smoke mass at Detling, North Kensington and Harwell was 0.78, 0.87 and 1.0 �g m-3, respectively. At all the sites, biomass burning was found to be a source of OC and EC, with the largest source of OC and EC found to be secondary organic aerosols and traffic emissions, respectively. Peaks in levoglucosan concentrations at the sites were observed to coincide with low ambient temperature, suggesting domestic heating as a contributing source in London. Overall, the source of biomass burning in London was likely a background regional source from mainland Europe overlaid by high contributions from local domestic burning emissions. This could have implications when considering future control strategies during winter. References Fuller, G.W., Sciare, J., Lutz, M., Moukhtar, S., Wagener, S., 2013. New Directions: Time to tackle urban wood burning? Atmospheric Environment 68, 295-296.
Crilley, Leigh; Bloss, William; Yin, Jianxin; Beddows, David; Harrison, Roy; Zotter, Peter; Prevot, Andre; Green, David
Sharp View of Gullies in Southern Winter
NASA Technical Reports Server (NTRS)20 November 2006 Crisp details in a suite of mid-latitude gullies on a crater wall are captured in this Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) view obtained in southern winter on 12 October 2006. During southern winter, shadows are more pronounced and the atmosphere is typically quite clear. These gullies, which may have formed in relatively recent martian history by erosion caused by flowing, liquid water, are located in a crater on the east rim of Newton Crater near 40.4oS, 155.3oW. Sunlight illuminates the scene from the upper left. The picture covers an area about 3 km (1.9 mi) wide; the crater rim is on the right side of the image, the crater floor is on the left. North is toward the top/upper left.
Changes in hematological profiles during winter field operations
The authors have previously shown that there are changes in hematological profiles during experimental cold acclimation. They now report on hematological changes in 9 military volunteers during a 12 week winter field operation and show results similar to those observed during experimental cold acclimation. Blood was collected before and after completion of winter field operations and analyzed in a paired fashion. Hematocrit (HCT) and erythrocyte counts (RBC) were decreased; mean corpuscular hemoglobin concentration (MCHC) and plasma volume (PV), which was calculated from hemoglobin (Hb) concentration and HCT, were increased. In addition, the reticulocyte count was increased from 1.37 {plus minus} 0.10% to 2.62 {plus minus} 0.24% after completion of field operations. There was a statistically significant inverse correlation between HCT and reticulocyte count, indicating the need for an enhanced rate of red cell production. Hemoglobin concentration, leukocyte count, and mean corpuscular volume were unchanged. The RBC population, to remain at steady state during periods of chronic cold exposure, shows alterations in the number of circulating cells, Hb concentration per cell and possibly cell turnover.
Lopez, A.; Reed, L.; D'Alesandro, M. (Naval Medical Research Inst., Bethesda, MD (United States))
Impact of future warming on winter chilling in Australia.
Increases in temperature as a result of anthropogenically generated greenhouse gas (GHG) emissions are likely to impact key aspects of horticultural production. The potential effect of higher temperatures on fruit and nut trees' ability to break winter dormancy, which requires exposure to winter chilling temperatures, was considered. Three chill models (the 0-7.2�C, Modified Utah, and Dynamic models) were used to investigate changes in chill accumulation at 13 sites across Australia according to localised temperature change related to 1, 2 and 3�C increases in global average temperatures. This methodology avoids reliance on outcomes of future GHG emission pathways, which vary and are likely to change. Regional impacts and rates of decline in chilling differ among the chill models, with the 0-7.2�C model indicating the greatest reduction and the Dynamic model the slowest rate of decline. Elevated and high latitude eastern Australian sites were the least affected while the three more maritime, less elevated Western Australian locations were shown to bear the greatest impact from future warming. PMID:22674019
Darbyshire, Rebecca; Webb, Leanne; Goodwin, Ian; Barlow, E W R
Impact of future warming on winter chilling in Australia
NASA Astrophysics Data System (ADS)
Increases in temperature as a result of anthropogenically generated greenhouse gas (GHG) emissions are likely to impact key aspects of horticultural production. The potential effect of higher temperatures on fruit and nut trees' ability to break winter dormancy, which requires exposure to winter chilling temperatures, was considered. Three chill models (the 0-7.2�C, Modified Utah, and Dynamic models) were used to investigate changes in chill accumulation at 13 sites across Australia according to localised temperature change related to 1, 2 and 3�C increases in global average temperatures. This methodology avoids reliance on outcomes of future GHG emission pathways, which vary and are likely to change. Regional impacts and rates of decline in chilling differ among the chill models, with the 0-7.2�C model indicating the greatest reduction and the Dynamic model the slowest rate of decline. Elevated and high latitude eastern Australian sites were the least affected while the three more maritime, less elevated Western Australian locations were shown to bear the greatest impact from future warming.
Darbyshire, Rebecca; Webb, Leanne; Goodwin, Ian; Barlow, E. W. R.
Assessing solar energy and water use efficiencies in winter wheat
NASA Technical Reports Server (NTRS)
The water use and solar energy conversion efficiencies of two cultivars of winter wheat (Triticum aestivum L., vars, Centurk and Newton) planted at three densities, were examined during a growing season. Water use, based on soil moisture depletion, was the lowest under the light, and the highest under the heavy planting densities of both cultivars. Water use efficiency of medium and heavy planting densities were greater than the light planting densities in both cultivars. The canopy radiation extinction coefficients of both cultivars increased with increases in planting density. Efficiency of operation interception of photosynthetically active radiation by both cultivars improved from the time of jointing until anthesis, and then decreased during senescence. The efficiency of the conversion of intercepted radiation to dry matter (biochemical efficiency) decreased throughout the growing season both cultivars. The interception, biochemical, and photosynthetic efficiencies improved as planting density increased.
Asrar, G.; Hipps, L. E.; Kanemasu, E. T.
Tracking a Winter Storm Across the USA
NSDL National Science Digital Library
In this activity, students track a real winter storm, collect imagery and data, perform an analysis, and make predictions on the storm's path. They will summarize their findings by writing a press release for their local radio station or by producing a report with visuals and graphics for a television broadcast. Instructions for downloading and processing data, images, and weather reports are presented along with ideas for graphing and viewing the material. Extension activities are also provided.
Act now to avoid winter deaths.
Essential facts [Figure: see text] Cold weather has a direct effect on the number of people experiencing heart attacks, stroke, respiratory disease and flu. According to the Office for National Statistics, an estimated 31,100 excess winter deaths occurred in England and Wales in 2012/13 - a rise of 29 per cent compared with the previous year. Of these people, 25,600 were aged 75 or above. PMID:25052647
Winter Temperature Affects the Prevalence of Ticks in an Arctic Seabird
The Arctic is rapidly warming and host-parasite relationships may be modified by such environmental changes. Here, I showed that the average winter temperature in Svalbard, Arctic Norway, explained almost 90% of the average prevalence of ticks in an Arctic seabird, the Br�nnich�s guillemot Uria lomvia. An increase of 1�C in the average winter temperature at the nesting colony site was associated with a 5% increase in the number of birds infected by these ectoparasites in the subsequent breeding season. Guillemots were generally infested by only a few ticks (?5) and I found no direct effect of tick presence on their body condition and breeding success. However, the strong effect of average winter temperature described here clearly indicates that tick-seabird relationships in the Arctic may be strongly affected by ongoing climate warming.
Descamps, Sebastien
Soft Wheat Milling and Baking Quality in a Soft Red Winter X Hard Red Winter Wheat Population
Cereal Chem. 66(5):378-381 A single-cross soft red winter X hard red winter wheat population and high SE and adjusted flour yield, indicating acceptable preliminary was evaluated in the F3, F4, and F5 generations for preliminary soft red soft red winter wheat milling and baking quality. Narrow sense heritability winter wheat milling and baking quality. Tests conducted included the estimates for
Solar wind influence on atmospheric processes in winter Antarctica
NASA Astrophysics Data System (ADS)
The experimental results demonstrate influence of the great southward interplanetary magnetic field (IMF) and the corresponding geoeffective interplanetary electric field on atmospheric pro-cesses in the central Antarctica, where the large-scale system of vertical circulation takes place during the winter seasons. The interplanetary electric field influence is realized through ac-celeration of the air masses, descending into the lower atmosphere from the troposphere, and formation of cloudiness above the Antarctic Ridge, where the descending air masses enter the surface layer. The cloudiness results in the sudden warmings in the surface atmosphere, because the cloud layer efficiently backscatters the long wavelength radiation going from ice sheet, but does not affect the process of adiabatic warming of the descending air masses. Influence of the interplanetary electric field on cloudiness has been revealed for epochs of the solar activity minimum, when Forbush decreases effect is absent. The altitudinal profiles of temperature, varying in the opposite manner under influence of the southward and northward IMF, indicate that the cloud layer formation occurs at h = 8 -10 km. The acceleration of the descending air masses is followed by a sharp increase of the atmospheric pressure in the near-pole region, which gives rise to the katabatic wind strengthening above the entire Antarctica. As a result, the circumpolar vortex around the periphery of the Antarctic continent decays and the surface easterlies, typical of the coast stations during the winter season, are replaced by southerlies. It is suggested that the resulting invasion of the cold air masses into the Southern ocean leads to destruction the regular relationships between the sea level pressure fluctuations in the South-east Pacific high and the North Australian-Indonesian low, since development the El-Ni�o event n strongly follows anomalous atmospheric processes in the winter Antarctica.
Troshichev, Oleg; Egorova, Larisa; Vovk, Valery; Janzhura, Alexander
Dehydration in the Winter Arctic Tropopause Region
NASA Technical Reports Server (NTRS)
Recent work has shown that limited amounts of tropospheric air can penetrate as much as 1 km into the middleworld stratosphere during the arctic winter. This, coupled with temperatures that are cold enough to produce saturation mixing ratios of less than 5 ppmv at the tropopause, results in stratospheric cloud formation and upper tropospheric dehydration. Even though these "cold outbreaks" occupy only a small portion of the area in the arctic (1-2%), their importance is magnified by an order of magnitude because of the air flow through them. This is reinforced by evidence of progressive drying through the winter measured during SOLVE-1. The significance of this process lies in its effect on the upper tropospheric water content of the middle and high latitude tropopause region, which plays an important role in regulating the earth's radiative balance. There appears to be significant year-to-year variability in the incidence of the cold outbreaks. This work has two parts. First, we describe case studies of dehydration taken from the SOLVE and SOLVE2 aircraft sampling missions during the Arctic winters of 2000 and 2003 respectively. Trajectory based microphysical modeling is employed to examine the sensitivity of the dehydration to microphysical parameters and the nature of sub-grid scale temperature fluctuations. We then examine the year-to-year variations in potential dehydration using a trajectory climatology.
Pfister, Leonhard; Jensen, Eric; Podolske, James; Selkirk, Henry; Anderson, Bruce; Avery, Melody; Diskin. Glenn
Effects of weather on habitat selection and behavior of mallards wintering in Nebraska
Sex and age ratios, habitat selection, spatial characteristics, and time budgets of Mallards (Anas platyrhynchos) wintering on the Platte River in south central Nebraska were studied from mid-December to early April 1978-1980. The proportion of females and subadults in the population increased substantially from a cold to a mild winter. Radio-tagged Mallards shifted from riverine to canal roost sites during the coldest periods of the winter, seemingly because of more favorable microclimatic conditions there. Subadults ranged over larger areas during winter than did adults. Activity patterns varied with weather conditions, time of day, and habitat type. During cold periods, energetically costly activities such as aggression and courtship decreased at roost sites and the intensity of foraging activities in fields increased. Mallards were more active at riverine than canal sites during both years. High energy requirements and intense competition for scarce food appear to be primary factors limiting the northernmost distribution of Mallards in winter and causing their skewed sex and age ratios.
Jorde, D. G.; Krapu, G. L.; Crawford, R. D.; Hay, M. A.
Recent trends in winter temperature extremes in eastern China and their relationship with the Arctic Oscillation and ENSO
NASA Astrophysics Data System (ADS)
Interannual variations in the number of winter extreme warm and cold days over eastern China (EC) and their relationship with the Arctic Oscillation (AO) and El Ni�o-Southern Oscillation (ENSO) were investigated using an updated temperature dataset comprising 542 Chinese stations during the period 1961-2011. Results showed that the number of winter extreme warm (cold) days across EC experienced a significant increase (decrease) around the mid-1980s, which could be attributed to interdecadal variation of the East Asian Winter Monsoon (EAWM). Probability distribution functions (PDFs) of winter temperature extremes in different phases of the AO and ENSO were estimated based on Generalized Extreme Value Distribution theory. Correlation analysis and the PDF technique consistently demonstrated that interannual variation of winter extreme cold days in the northern part of EC (NEC) is closely linked to the AO, while it is most strongly related to the ENSO in the southern part (SEC). However, the number of winter extreme warm days across EC has little correlation with both AO and ENSO. Furthermore, results indicated that, whether before or after the mid-1980s shift, a significant connection existed between winter extreme cold days in NEC and the AO. However, a significant connection between winter extreme cold days in SEC and the ENSO was only found after the mid-1980s shift. These results highlight the different roles of the AO and ENSO in influencing winter temperature extremes in different parts of EC and in different periods, thus providing important clues for improving short-term climate prediction for winter temperature extremes.
Chen, Shangfeng; Chen, Wen; Wei, Ke
Association of wintering raptors with Conservation Reserve Enhancement Program grasslands in Pennsylvania
Conservation grasslands can provide valuable habitat resource for breeding songbirds, but their value for wintering raptors has received little attention. We hypothesized that increased availability of grassland habitat through the Conservation Reserve Enhancement Program (CREP) has resulted in an increase or redistribution in numbers of four species of raptors in Pennsylvania since 2001. We tested this by analyzing winter raptor counts from volunteer surveys, conducted from 2001 to 2008, for Red-tailed Hawks (Buteo jamaicensis), Rough-legged Hawks (Buteo lagopus), Northern Harriers (Circus cyaneus), and American Kestrels (Falco sparverius). During that period, numbers of wintering Northern Harriers increased by more than 20% per year. Log-linear Poisson regression models show that all four species increased in the region of Pennsylvania that had the most and longest-established conservation grasslands. At the county scale (N= 67), Bayesian spatial models showed that spatial and temporal population trends of all four species were positively correlated with the amount of conservation grassland. This relationship was particularly strong for Northern Harriers, with numbers predicted to increase by 35.7% per year for each additional 1% of farmland enrolled in CREP. Our results suggest that conservation grasslands are likely the primary cause of the increase in numbers of wintering Northern Harriers in Pennsylvania since 2001. ?? 2010 The Authors. Journal of Field Ornithology ?? 2010 Association of Field Ornithologists.
Wilson, A.; Brittingham, M.; Grove, G.
Slips and falls on ice and snow in relation to experience in winter climate and winter sport
The objective of this paper was to investigate whether living experience in winter climate and winter sport helps to prevent slips and falls on ice and snow. A questionnaire survey was conducted among foreigners at Lule� University of Technology of Sweden, where winter season lasts for six months in a year. Seventy respondents replied. The results of ordinal regression showed
Chuansi Gao; John Abeysekera
Observation of Current and Leader Development Characteristics of Winter Lightning
NASA Astrophysics Data System (ADS)
Current and leader development characteristics of winter lightning occurring in the coastal area of the Sea of Japan are reviewed. The characteristics of winter lightning are different from those of usual lightning that occurs mainly in summer. The occurrence of upward flashes, the percentage of current polarities, and the median values of current peaks in winter lightning are summarized. Typical current waveforms and the corresponding leader developments of winter lightning observed at the chimney of the Fukui thermal plant are shown. We examined the parameters (peak, duration, charge transfer, action integral) of the current waveforms of winter lightning.
Miki, Megumu
Excess winter mortality in Europe: a cross country analysis identifying key risk factors
Objective: Much debate remains regarding why certain countries experience dramatically higher winter mortality. Potential causative factors other than cold exposure have rarely been analysed. Comparatively less research exists on excess winter deaths in southern Europe. Multiple time series data on a variety of risk factors are analysed against seasonal-mortality patterns in 14 European countries to identify key relations Subjects and setting: Excess winter deaths (all causes), 1988�97, EU-14. Design: Coefficients of seasonal variation in mortality are calculated for EU-14 using monthly mortality data. Comparable, longitudinal datasets on risk factors pertaining to climate, macroeconomy, health care, lifestyle, socioeconomics, and housing were also obtained. Poisson regression identifies seasonality relations over time. Results: Portugal suffers from the highest rates of excess winter mortality (28%, CI=25% to 31%) followed jointly by Spain (21%, CI=19% to 23%), and Ireland (21%, CI=18% to 24%). Cross country variations in mean winter environmental temperature (regression coefficient (�)=0.27), mean winter relative humidity (�=0.54), parity adjusted per capita national income (�=1.08), per capita health expenditure (�=-1.19), rates of income poverty (�=-0.47), inequality (�=0.97), deprivation (�=0.11), and fuel poverty (�=0.44), and several indicators of residential thermal standards are found to be significantly related to variations in relative excess winter mortality at the 5% level. The strong, positive relation with environmental temperature and strong negative relation with thermal efficiency indicate that housing standards in southern and western Europe play strong parts in such seasonality. Conclusions: High seasonal mortality in southern and western Europe could be reduced through improved protection from the cold indoors, increased public spending on health care, and improved socioeconomic circumstances resulting in more equitable income distribution.
Healy, J
Winter risk estimations through infrared cameras an principal component analysis
NASA Astrophysics Data System (ADS)
Thermal mapping has been implemented since the late eighties to measure road pavement temperature along with some other atmospheric parameters to establish a winter risk describing the susceptibility of road network to ice occurrence. Measurements are done using a vehicle circulating on the road network in various road weather conditions. When the dew point temperature drops below road surface temperature a risk of ice occurs and therefore a loss of grip risk for circulating vehicles. To avoid too much influence of the sun, and to see the thermal behavior of the pavement enhanced, thermal mapping is usually done before dawn during winter time. That is when the energy accumulated by the road during daytime is mainly dissipated (by radiation, by conduction and by convection) and before the road structure starts a new cycle. This analysis is mainly done when a new road network is built, or when some major pavement changes are made, or when modifications in the road surroundings took place that might affect the thermal heat balance. This helps road managers to install sensors to monitor road status on specific locations identified as dangerous, or simply to install specific road signs. Measurements are anyhow time-consuming. Indeed, a whole road network can hardly be analysed at once, and has to be partitioned in stretches that could be done in the open time window to avoid temperature artefacts due to a rising sun. The LRPC Nancy has been using a thermal mapping vehicle with now two infrared cameras. Road events were collected by the operator to help the analysis of the network thermal response. A conventional radiometer with appropriate performances was used as a reference. The objective of the work was to compare results from the radiometer and the cameras. All the atmospheric parameters measured by the different sensors such as air temperature and relative humidity were used as input parameters for the infrared camera when recording thermal images. Road thermal heterogeneities were clearly identified, while usually missed by a conventional radiometer. In the case presented here, the two lanes of the road could be properly observed. Promising perspectives appeared to increase the measurement rate. Furthermore, to cope with the climatic constraints of the winter measurements as to build a dynamic winter risk, a multivariate data analysis approach was implemented. Principal component analysis was performed and enabled to set up of dynamic thermal signature with a great agreement between statistical results and field measurements.
Marchetti, M.; Dumoulin, J.; Ibos, L.
Summer melt regulates winter glacier flow speeds throughout Alaska (Invited)
NASA Astrophysics Data System (ADS)
Projecting the long-term response of glacier and ice sheet flow to climate change remains the single largest hurdle towards accurate sea level rise forecasting. Increases in surface melt rates are known to accelerate glacier flow in spring and summer1-4 whereas in winter, flow speeds have been found to be relatively invariant5. Here we find that wintertime flow velocities on nearly all major glaciers throughout Alaska are not only variable but are inversely correlated with summertime positive degree days (PDDs). The response is slight--an 11% decrease in wintertime velocity per additional meter of summertime melt. The mechanism is likely due to inter-annual differences in summertime meltwater production, which affect the efficiency of sub-glacial drainage systems to evacuate water from the glacier bed in fall. Consequent inter-annual variation in the amount of bed separation come winter leads to the observed differences in flow speed. We find this mechanism to be ubiquitous in Alaska and thus is likely a global phenomenon. If the dynamic evolves over the long-term, it represents a new mechanism affecting sea level rise contributions.
Burgess, E. W.; Forster, R. R.; Larsen, C. F.
Processes Controlling Water Vapor in the Winter Arctic Tropopause Region
NASA Technical Reports Server (NTRS)
This work describes transport and thermodynamic processes that control water vapor near the tropopause during the SAGE Ozone Loss and Validation Experiment (SOLVE), held during the Arctic 1999-2000 winter season. Aircraft based water vapor, carbon monoxide, and ozone measurements are analyzed so as to establish how deeply tropospheric air mixes into the arctic lower-most stratosphere, and what the implications are for cloud formation and water vapor removal in this region of the atmosphere. There are three major findings. First, troposphere-to- stratosphere exchange extends into the arctic stratosphere to about 13 km. Penetration is to similar levels throughout the winter, however, because ozone increases idly in the early spring, tropospheric air mixes with the highest values of ozone in that season. The effect of this upward mixing is to elevate water vapor mixing ratios significantly above their prevailing stratospheric values of about 5 ppmv. Second, the potential for cloud formation in the stratosphere is highest during early spring, with about 20\\% of the parcels which have ozone values of 300-350ppbv experiencing ice saturation in a given 10 day period. Third, during early Spring temperatures at the tropopause are cold enough so that 5-10\\% of parcels experience relative humidities above 100\\%, even if the water content is as low as 5 ppmv. The implication is that during, this period the arctic tropopause can play an important role in maintaining a very dry upper troposphere during early Spring.
Pfister, Leonhard; Selkirk, Henry B.; Jensen, Eric J.; Podolske, James; Sachse, Glen; Avery, Melody; Schoeberl, Mark R.; Hipskino, R. Stephen (Technical Monitor)
Processes Controlling Water Vapor in the Winter Arctic Tropopause Region
NASA Technical Reports Server (NTRS)
This work describes transport and thermodynamic processes that control water vapor near the tropopause during the SAGE III-Ozone Loss and Validation Experiment (SOLVE), held during the Arctic 1999/2000 winter season. Aircraft-based water vapor, carbon monoxide, and ozone measurements were analyzed so as to establish how deeply tropospheric air mixes into the Arctic lowermost stratosphere and what the implications are for cloud formation and water vapor removal in this region of the atmosphere. There are three major findings. First, troposphere-to-stratosphere exchange extends into the Arctic stratosphere to about 13 km. Penetration is to similar levels throughout the winter, however, because ozone increases with altitude most rapidly in the early spring, tropospheric air mixes with the highest values of ozone in that season. The effect of this upward mixing is to elevate water vapor mixing ratios significantly above their prevailing stratospheric values of above 5ppmv. Second, the potential for cloud formation in the stratosphere is highest during early spring, with about 20% of the parcels which have ozone values of 300-350 ppbv experiencing ice saturation in a given 10 day period. Third, during early spring, temperatures at the troposphere are cold enough so that 5-10% of parcels experience relative humidities above 100%, even if the water content is as low as 5 ppmv. The implication is that during this period, dynamical processes near the Arctic tropopause can dehydrate air and keep the Arctic tropopause region very dry during early spring.
Pfister, Leonhard; Selkirk, Henry B.; Jensen, Eric J.; Padolske, James; Sachse, Glen; Avery, Melody; Schoeberl, Mark R.; Mahoney, Michael J.; Richard, Erik
Environmental contaminants in redheads wintering in coastal Louisiana and Texas
Whole body and liver analyses indicated that wintering redheads (Aythya americana; n=70) in coastal Louisiana (one site) and Texas (two sites) were relatively free of contamination with common trace elements, organochlorines, and hydrocarbons. Most trace elements, including As, Cr, Hg, Mg, Mn, Ni, Pb, Se, Sr, and Zn, were within background concentrations in livers; levels of B, Cd, Cu, and Fe were elevated in some specimens. Only one organochlorine, DDE, was detected in redhead carcasses, but its concentration was below reported toxic levels in waterfowl. Body burdens of aliphatic and aromatic hydrocarbons were generally low, but levels of pristane, total hydrocarbons, and the ratios of phytane:n-octadecane and pristane:n-heptadecane were indicative of possible chronic exposure to petroleum. Based on brain cholinesterase assays, redheads were not recently exposed to organophosphorous or carbamate pesticides. Of 30 elements or compounds tested for seasonal differences, only Se increased from early to late winter at one of the three sites. Eight of 57 contaminants differed among the three sites; no sex or age differences were found.
Michot, T. C.; Custer, T. W.; Nault, A. J.; Mitchell, C. A.
Environmental contaminants in redheads wintering in coastal Louisiana and Texas
Whole body and liver analyses indicated that wintering redheads (Aythya americana; n = 70) in coastal Louisiana (one site) and Texas (two sites) were relatively free of contamination with common trace elements, organochlorines, and hydrocarbons. Most trace elements, including As, Cr, Hg, Mg, Mn, Ni, Pb, Se, Sr, and Zn, were within background concentrations in livers; levels of B, Cd, Cu, and Fe were elevated in some specimens. Only one organochlorine, DDE, was detected in redhead carcasses, but its concentration was below reported toxic levels in waterfowl. Body burdens of aliphatic and aromatic hydrocarbons were generally low, but levels of pristane, total hydrocarbons, and the ratios of phytane:n-octadecane and pristane:n-heptadecane were indicative of possible chronic exposure to petroleum. Based on brain cholinesterase assays, redheads were not recently exposed to organophosphorous or carbamate pesticides. Of 30 elements or compounds tested for seasonal differences, only Se increased from early to late winter at one of the three sites. Eight of 57 contaminants differed among the three sites; no sex or age differences were found.
Michot, T. C.; Custer, T. W.; Nault, A. J.; Mitchell, C. A.
Climate and smoke: an appraisal of nuclear winter.
The latest understanding of nuclear winter is reviewed. Considerable progress has been made in quantifying the production and injection of soot by large-scale fires, the regional and global atmospheric dispersion of the soot, and the resulting physical, environmental, and climatic perturbations. New information has been obtained from laboratory studies, field experiments, and numerical modeling on a variety of scales (plume, mesoscale, and global). For the most likely soot injections from a full-scale nuclear exchange, three-dimensional climate simulations yield midsummer land temperature decreases that average 10 degrees to 20 degrees C in northern mid-latitudes, with local cooling as large as 35 degrees C, and subfreezing summer temperatures in some regions. Anomalous atmospheric circulations caused by solar heating of soot is found to stabilize the upper atmosphere against overturning, thus increasing the soot lifetime, and to accelerate interhemispheric transport, leading to persistent effects in the Southern Hemisphere. Serious new environmental problems associated with soot injection have been identified, including disruption of monsoon precipitation and severe depletion of the stratospheric ozone layer in the Northern Hemisphere. The basic physics of nuclear winter has been reaffirmed through several authoritative international technical assessments and numerous individual scientific investigations. Remaining areas of uncertainty and research priorities are discussed in view of the latest findings. PMID:11538069
Turco, R P; Toon, O B; Ackerman, T P; Pollack, J B; Sagan, C
Drifting invertebrates, stomach contents, and body conditions of juvenile rainbow trout from fall through winter in a Wyoming tailwater
We investigated the availability of drifting invertebrates and the stomach contents and body conditions of stocked (hatchery) and naturally spawned (wild) juvenile (20-25 cm total length) rainbow trout from fall through winter in the Big Horn River downstream from Boysen Dam in Wyoming. When the density and biomass of drifting invertebrates declined with water temperature during the fall, stomach contents and body conditions substantially decreased among both wild and stocked fish. During the coldest portion of the winter, the density of small drifting invertebrates increased as did the body conditions of both wild and hatchery trout. We suggest that the perceived increase in body conditions during late winter was due to survival of fish with higher body conditions and not growth of fish from fall to late winter.
Simpkins, D. G.; Hubert, W. A.
Stable isotope evidence of diverse species-specific and individual wintering strategies in seabirds
Although there is increasing evidence that climatic variations during the non-breeding season shape population dynamics of seabirds, most aspects of their winter distribution and ecology remain essentially unknown. We used stable isotope signatures in feathers to infer and compare the moulting (wintering) habitat of subantarctic petrels breeding at two distant localities (South Georgia and Kerguelen). Petrels showed species-specific wintering habitat preferences, with a similar pattern of latitudinal segregation for all but one taxon. At both localities, ?13C values indicated that blue petrels (Halobaena caerulea) moult in Antarctic waters, South Georgian diving petrels (Pelecanoides georgicus) in the vicinity of the archipelagos and/or in the Polar Frontal Zone and Antarctic prions (Pachyptila desolata) in warmer waters. In contrast, common diving petrels (Pelecanoides urinatrix) showed divergent strategies, with low and high intrapopulation variation at South Georgia and Kerguelen, respectively. Birds from Kerguelen dispersed over a much wider range of habitats, from coastal to oceanic waters and from Antarctica to the subtropics, whereas those from South Georgia wintered mainly in waters around the archipelago. This study is the first to show such striking between-population heterogeneity in individual wintering strategies, which could have important implications for likely demographic responses to environmental perturbation.
Cherel, Y; Phillips, Richard A; Hobson, Keith A; McGill, Rona
Adaptation of Camelus dromedarius pars nervosa of the hypophysis to winter and summer living conditions.
The aim of this work is to study the characteristics of the dromedary nervous lobe and determine how the seasons condition its organization. To this end, electron microscopy was performed and examined quantitatively on animals from winter and summer periods. The results show a higher number of cells in the nervous lobe in summer than in winter. The most abundant glial elements in winter are light pituicytes engulfing neurosecretory nerve fibers making neuroglial contact, and dark pituicytes containing numerous heterogeneous light bodies. In summer, the most distinctive glial cells may be pituicytes in a phagocytic state making contact with characteristic large light bodies that could represent a degenerative process of large neuropeptide storage. Granular pituicytes were also observed in contact with glial and neuronal components. However, lipid droplets, described in pituicytes of other mammals, were not observed in our samples. Quantitative analysis of neurovascular contacts revealed that the number of nerve terminals contacting the basal lamina did not differ between summer and winter, but the mean number of glial processes increased in winter. Our data provides evidence that the storage of neuropeptides is very marked in summer and that, associated with an autophagic and phagocytic phenomenon, this suggests an adaptation to anticipate any situation that would cause dehydration of the dromedary. Thus, in its tough environment, the animal remains permanently prepared to avoid any large water loss. PMID:22763958
Djazouli Alim, Fatma Zohra; Rodr�guez, Manuel Jose; Andrade, Carmen; Lebaili, Nemcha; Mahy, Nicole
The use of partial thickness method and zero wet bulb temperature for discriminating precipitation type during winter months at the Ebro basin in Spain
NASA Astrophysics Data System (ADS)
The forecast office of the State Meteorological Agency of Spain (AEMET) which is located in the city of Zaragoza provides weather forecast, warnings and aviation forecast products for Arag�n, Navarra and La Rioja regions. This area of Spain lies mainly on the Ebro river basin. Although the likelihood of snowfall in this territory is low, a forecasting of snow-depth higher than 5cm for low elevations activates the orange warning which must be issued to local emergency management and civil protection authorities. Zero wet bulb temperature has been historically the main tool for forecasting the altitude of snow-rain boundary at the forecast office; it shows the freezing level limit due to evaporational cooling when lower troposphere is saturated from aloft. This work adds two new parameters, the 1000-850 mb and the 850-700 mb thickness in order to characterize the thermal structure of surface based cold air and atmospheric mid-levels. The three main airports in this area Zaragoza-Arag�n, Logro�o-La Rioja and Pamplona-Navarra are located at altitudes below 500 m. They are thus suitable for this study. In addition, more than 16 years of meteorological observations every hour, known as METAR (Meteorological Aerodrome Report), are available at these locations. These observations were analysed and the predominant precipitation type during a six-hour period was characterized. The 00h, 06h, 12h and 18h analysis time of the ECMWF Forecast model were employed in order to get the parameters at the day and time when the precipitation took place. The most representative grid point of the model for each airport was chosen in order to illustrate the atmospheric conditions. A correlation between precipitation type and zero wet bulb temperature, 1000-850 mb and the 850-700 mb thickness was done for more than 230 different situations during a 16 year period. As a result, we plotted a series of site specific charts for each airport based on these parameters, in order to describe the environment favouring each precipitation type. This method is a simple technique for discriminating the different precipitation types. It also provides climatology of snowfall events for each airport, showing the differences due to their geographical location and how different synoptic conditions affect each place.. In the middle of Ebro basin, where Zaragoza airport is placed, the critical parameter to determine the precipitation type is the 1000 - 850 mb thickness. It is possible to find many episodes of snowfall with a very thin 1000-850 mb layer within a wide range of zero wet bulb temperature values. This shows the pool of cold air in the valley over which warm and moist air is advected from the Mediterranean Sea. Located close to the Cantabric sea, Pamplona is about 150 km north of Zaragoza. The snow episodes in this location are more related with cold air in all levels together with a narrow range of zero wet bulb temperature values. The results show that the Logro�o area, 150 km northwest of Zaragoza, is influenced by both conditions. This method became operational during 2009-2010 winter season showing a high degree of accuracy in discriminating precipitation type.
Buisan, S.; Revuelto, J.
An analysis of long-term winter data on phytoplankton and zooplankton in Neusiedler See, a shallow temperate lake, Austria
In the last 40�years, the shallow steppe lake, Neusiedler See, was ice covered between 0 and 97�days. The North Atlantic Oscillation\\u000a (NAO) as well as the Mediterranean Oscillation affected the lake and its conditions during winter. Both climate indices correlated\\u000a negatively with the duration of ice cover and the timing of ice-out. Average winter phytoplankton biomass increased from less\\u000a than
Martin T. Dokulil; Alois Herzig
Deeper Snow Enhances Winter Respiration from Both Plant-associated and Bulk Soil Carbon Pools in Birch Hummock Tundra
It has only recently become apparent that biological activity during winter in seasonally snow-covered ecosystems may exert\\u000a a significant influence on biogeochemical cycling and ecosystem function. One-seventh of the global soil carbon pool is stored\\u000a in the bulk soil component of arctic ecosystems. Consistent climate change predictions of substantial increases in winter\\u000a air temperatures and snow depths for the Arctic
Sonia Nobrega; Paul Grogan
Potential bioethanol and biogas production using lignocellulosic biomass from winter rye, oilseed rape and faba bean
To meet the increasing need for bioenergy several raw materials have to be considered for the production of e.g. bioethanol and biogas. In this study, three lignocellulosic raw materials were studied, i.e. (1) winter rye straw (Secale cereale L), (2) oilseed rape straw (Brassica napus L.) and (3) faba bean straw (Viciafaba L.). Their composition with regard to cellulose, hemicellulose,
Anneli Petersson; Mette H. Thomsen; Henrik Hauggaard-Nielsen; Anne-Belinda Thomsen
Trend analysis of winter rainfall over southern Qu�bec and new Brunswick (Canada)
Winter rainfall is a non?negligible issue for urban drainage in Canada as it can generate significant flooding, especially when it occurs at the same time as high air temperature and in the presence of an appreciable snow cover. According to climate change scenarios, it is expected that the occurrence of these events will increase in a future climate. The purpose
Audrey Groleau; Alain Mailhot; Guillaume Talbot
Weed populations and pickling cucumber ( Cucumis sativus) yield under summer and winter cover crop systems
Cucumber growers are increasingly interested in integrating cover crops into their cropping systems. This study was conducted to measure the effect of summer and winter cover crops on weed populations and cucumber yield. The experimental design was a factorial of cover crop and killing method. The cover crops were sorghum sudangrass [Sorghum bicolor (L) x S. sudanense (P) Stapf.], cereal
M. Ngouajio; H. Mennan
Impact of outdoor winter sports on the abundance of a key indicator species of alpine ecosystems
Summary 1. Tourism and leisure activities have increased continuously all over the world during the past decades, exerting a growing pressure upon naturally fragile ecosystems, such as mountainous habitats. Recent studies have established that disturbance by outdoor winter sports (e.g. skiing, snowboarding and snowshoeing) is a source of stress for wildlife. This may in turn affect its abundance, but we
Patrick Patthey; Sven Wirthner; Natalina Signorell; Rapha�l Arlettaz
Commitment and Compassion: Boston's Comprehensive Policy for the Homeless. Winter Report, December 1989.
ERIC Educational Resources Information Center
The people of Boston made a commitment that no homeless person will be denied a bed, a meal, quality health care, and transportation to shelter during the winter of 1989-90. This commitment was difficult to fulfill due to a decline in services for the mentally ill, federal housing cutbacks, and an increase in the number of families living in�
Emergency Shelter Commission, Boston, MA.
Optimizing Nitrogen Application Timing in No-Till Soft Red Winter Wheat
resulted in the highest yields in these fields. Nitrogen applications at GS-25 can stimulate tiller development As no-till acreage increases, N management guidelines need re- in southeastern wheat production because winter wheat examination due to the potential effects of surface residue on N transformations and crop development. Our objectives were to deter- does not enter a dormant state in these
Randall Weisz; Carl R. Crozier; Ronnie W. Heiniger
Effects of Organic Fertilizers and Urea when Applied to Winter Wheat
In the present study, organic fertilizers, represented by slurry manure and meat bone meal, used on ecologically grown winter wheat were compared with urea in field experiments with the purpose of increasing the protein content. There were no consistent differences in protein content and yield level between the treatments with organic fertilizers and the urea treatments. The protein content was
Lennart Salomonsson; Ann-Christine Salomonsson; Stina Olofsson; Anders Jonsson
Effects of weather on daily body mass regulation in wintering dunlin
We investigated the influence of changes in weather associated with winter storms on mass balance, activity and food consumption in captive dunlin (Calidris alpina) held in outdoor aviaries, and compared the aviary results with weather-related body mass differences in free-living dunlin collected at Bolinas Lagoon, California. Captive birds fed ad libitum increased their body mass at higher wind speeds and
John P. Kelly; Nils Warnock; Gary W. Page; Wesley W. Weathers
Disentangling the effects of fertilisers and pesticides on winter stubble use by farmland birds
Cereal stubbles are a preferred foraging habitat for overwintering granivorous farmland bird species. Levels of this habitat have declined in recent decades across much of western Europe with increasing agricultural intensification. Organic farms typically hold more stubble fields than conventional farms and thus may provide important refuges for wintering birds. However, while organic stubble fields often contain higher food densities
Ailsa J. McKenzie; Juliet A. Vickery; Carlo Leifert; Peter Shotton; Mark J. Whittingham
Changes in starch and soluble sugar concentrations in winter squash mesocarp during storage at different temperatures
The effects of storage at 5, 10 or 15�C for 6 months on the concentrations of starch and soluble sugar in winter squash (Cucurbita maxima Duch.) cultivar �TC2A� fruits were examined. Starch contents were significantly lower at 15�C than at the other temperatures, although concentrations decreased throughout the storage period at all temperatures. Total soluble sugar contents increased during the
Daisuke Kami; Takato Muro; Keita Sugiyama
Responses of woodland caribou to winter ecotourism in the Charlevoix Biosphere Reserve, Canada
We assessed the impact of ecotourist visits during winter on woodland caribou Rangifer tarandus caribou time budgets in the Charlevoix Biosphere Reserve, Canada. We compared the behaviour of caribou during and after ecotourist visits with their behaviour during days without visits. In the presence of ecotourists, caribou increased time spent vigilant and standing, mostly at the expense of time spent
Mario Duchesne; Steeve D C�t�; Cyrille Barrette
ABsTRKr.-Social organization, movements, and home ranges of Blue Grouse (Den- drugupus obscurus) were investigated on Hardwicke Island, British Columbia from 1979 to 1982. Most broods disbanded by the end of September, and young grouse did not associate with their mothers or siblings in winter. The tendency to form flocks was lowest in fall. Grouping increased gradually until midwinter and then
Cumulative Impacts of Tourist Resorts on Wild Reindeer (Rangifer tarandus tarandus) during Winter
Potential avoidance by wild reindeer (Rangifer tarandus tarandus) of high-altitude tourist resorts during winter was investigated in and near Rondane National Park in Norway. Distribution of reindeer was mapped using systematic snowmobile surveys during 1991-96 and compared with results from investigations of snow and vegetation characteristics. Maternal reindeer avoided a 10 km zone around the resort. Cows and calves increased
Corpus cavernosum abscess after Winter procedure performance.
A 23-year-old male patient with sickle-cell disease reported his third episode of priapism complicated by the presence of a corpus cavernosum abscess after the performance of a Winter procedure 20 days prior to his presentation. While in hospital for 11 days, two penile needle aspirations and three surgical drainages were performed with associated antibiotic therapy. He evolved with erectile dysfunction refractory to drug therapy and his infectious condition improved. An early penile prosthesis implantation followed after the use of a vacuum pump in an attempt to decrease the fibrotic process of the corpora cavernosa. Final results were positive. PMID:24515231
Paladino, Joao Roberto; Nascimento, Fabio Jose; Gromatsky, Celso; Pompeo, Antonio Carlos Lima
USGS Multi-Hazards Winter Storm Scenario
NASA Astrophysics Data System (ADS)
The USGS began an inter-disciplinary effort, the Multi Hazards Demonstration Project (MHDP), in 2007 to demonstrate how hazards science can improve a community's resiliency to natural disasters including earthquakes, tsunamis, wildfires, landslides, floods and coastal erosion. The project engages the user community in setting research goals and directs efforts towards research products that can be applied to loss reduction and improved resiliency. The first public product of the MHDP was the ShakeOut Earthquake Scenario published in May 2008. It detailed the realistic outcomes of a hypothetical, but plausible, magnitude 7.8 earthquake on the San Andreas Fault in southern California. Over 300 scientist and experts contributed to designing the earthquake and understanding the impacts of such a disaster, including the geotechnical, engineering, social, cultural, environmental, and economic consequences. The scenario advanced scientific understanding and exposed numerous vulnerabilities related to emergency response and lifeline continuity management. The ShakeOut Scenario was the centerpiece of the Nation's largest-ever emergency response exercise in November 2008, dubbed "The Great Southern California ShakeOut" (www.shakeout.org). USGS Multi-Hazards is now preparing for its next major public project, a Winter Storm Scenario. Like the earthquake scenario, experts will be brought together to examine in detail the possibility, cost and consequences of a winter storm disaster including floods, landslides, coastal erosion and inundation; debris flows; biologic consequences like extirpation of endangered species; physical damages like bridge scour, road closures, dam failure, property loss, and water system collapse. Consideration will be given to the vulnerabilities associated with a catastrophic disruption to the water supply to southern California; the resulting impacts on ground water pumping, seawater intrusion, water supply degradation, and land subsidence; and a detailed examination on climatic change forces that could exacerbate the problems. Similar to the ShakeOut Scenario, the Winter Storm Scenario is designing a large but scientifically plausible physical event followed by an expert analysis of the secondary hazards, and the physical, social, and economic consequences. Unlike the earthquake scenario, the winter storm event may occur over days, weeks, and possibly months, and the stakeholder community is broadening to include resource managers as well as local governments and the emergency and lifeline management communities. Developing plans for this Scenario will be presented at this session, and feedback will be welcomed.
Cox, D. A.; Jones, L. M.; Perry, S. C.
Role of natural day-length and temperature in determination of summer and winter diapause in Pieris melete (Lepidoptera: Pieridae).
Under field conditions, the cabbage butterfly, Pieris melete, displays a pupal summer diapause in response to relatively low daily temperatures and gradually increasing day-length during spring and a pupal winter diapause in response to the progressively shorter day-length. To determine whether photoperiod is 'more' important than temperature in the determination of summer and winter diapause, or vice versa, the effects of naturally changing day-length and temperature on the initiation of summer and winter diapause were systematically investigated under field conditions for five successive years. Field results showed that the incidence of summer diapause significantly declined with the naturally increasing temperature in spring and summer generations. Path coefficient analysis showed that the effect of temperature was much greater than photoperiod in the determination of summer diapause. In autumn, the incidence of diapause was extremely low when larvae developed under gradually shortening day-length and high temperatures. The incidence of winter diapause increased to 60-90% or higher with gradually shortening day-length combined with temperatures between 20.0�C and 22.0�C. Decreasing day-length played a more important role in the determination of winter diapause induction than temperature. The eco-adaptive significance of changing day-length and temperature in the determination of summer and winter diapause was discussed. PMID:22030333
Xiao, H J; Wu, S H; He, H M; Chen, C; Xue, F S
Nonlinear effects of climate on boreal rodent dynamics: mild winters do not negate high-amplitude cycles.
Small rodents are key species in many ecosystems. In boreal and subarctic environments, their importance is heightened by pronounced multiannual population cycles. Alarmingly, the previously regular rodent cycles appear to be collapsing simultaneously in many areas. Climate change, particularly decreasing snow quality or quantity in winter, is hypothesized as a causal factor, but the evidence is contradictory. Reliable analysis of population dynamics and the influence of climate thereon necessitate spatially and temporally extensive data. We combined data on vole abundances and climate, collected at 33 locations throughout Finland from 1970 to 2011, to test the hypothesis that warming winters are causing a disappearance of multiannual vole cycles. We predicted that vole population dynamics exhibit geographic and temporal variation associated with variation in climate; reduced cyclicity should be observed when and where winter weather has become milder. We found that the temporal patterns in cyclicity varied between climatically different regions: a transient reduction in cycle amplitude in the coldest region, low-amplitude cycles or irregular dynamics in the climatically intermediate regions, and strengthening cyclicity in the warmest region. Our results did not support the hypothesis that mild winters are uniformly leading to irregular dynamics in boreal vole populations. Long and cold winters were neither a prerequisite for high-amplitude multiannual cycles, nor were mild winters with reduced snow cover associated with reduced winter growth rates. Population dynamics correlated more strongly with growing season than with winter conditions. Cyclicity was weakened by increasing growing season temperatures in the cold, but strengthened in the warm regions. High-amplitude multiannual vole cycles emerge in two climatic regimes: a winter-driven cycle in cold, and a summer-driven cycle in warm climates. Finally, we show that geographic climatic gradients alone may not reliably predict biological responses to climate change. PMID:23504828
Korpela, Katri; Delgado, Maria; Henttonen, Heikki; Korpim�ki, Erkki; Koskela, Esa; Ovaskainen, Otso; Pieti�inen, Hannu; Sundell, Janne; Yoccoz, Nigel G; Huitu, Otso
Echo Meadows Project Winter Artificial Recharge.
This report discusses the findings of the Echo Meadows Project (BPA Project 2001-015-00). The main purpose of this project is to artificially recharge an alluvial aquifer, WITH water from Umatilla River during the winter high flow period. In turn, this recharged aquifer will discharge an increased flow of cool groundwater back to the river, thereby improving Umatilla River water quality and temperature. A considerable side benefit is that the Umatilla River should improve as a habitat for migration, spanning, and rearing of anadromous and resident fish. The scope of this project is to provide critical baseline information about the Echo Meadows and the associated reach of the Umatilla River. Key elements of information that has been gathered include: (1) Annual and seasonal groundwater levels in the aquifer with an emphasis on the irrigation season, (2) Groundwater hydraulic properties, particularly hydraulic conductivity and specific yield, and (3) Groundwater and Umatilla River water quality including temperature, nutrients and other indicator parameters. One of the major purposes of this data gathering was to develop input to a groundwater model of the area. The purpose of the model is to estimate our ability to recharge this aquifer using water that is only available outside of the irrigation season (December through the end of February) and to estimate the timing of groundwater return flow back to the river. We have found through the data collection and modeling efforts that this reach of the river had historically returned as much as 45 cubic feet per second (cfs) of water to the Umatilla River during the summer and early fall. However, this return flow was reduced to as low as 10 cfs primarily due to reduced quantities of irrigation application, gain in irrigation efficiencies and increased groundwater pumping. Our modeling indicated that it is possible to restore these critical return flows using applied water outside of the irrigation season. We further found that this water can be timed to return to the river during the desired time of the year (summer to early fall). This is because the river stage, which remains relatively high until this time, drops during the irrigation season-thereby releasing the stored groundwater and increasing river flows. A significant side benefit is that these enhanced groundwater return flows will be clean and cold, particularly as compared to the Umatilla River. We also believe that this same type of application of water could be done and the resulting stream flows could be realized in other watersheds throughout the Pacific Northwest. This means that it is critical to compare the results from this baseline report to the full implementation of the project in the next phase. As previously stated, this report only discusses the results of data gathered during the baseline phase of this project. We have attempted to make the data that has been gathered accessible with the enclosed databases and spreadsheets. We provide computer links in this report to the databases so that interested parties can fully evaluate the data that has been gathered. However, we cannot emphasize too strongly that the real value of this project is to implement the phases to come, compare the results of these future phases to this baseline and develop the science and strategies to successfully implement this concept to other rivers in the Pacific Northwest. The results from our verified and calibrated groundwater model matches the observed groundwater data and trends collected during the baseline phase. The modeling results indicate that the return flows may increase to their historic values with the addition of 1 acre-ft/acre of recharge water to the groundwater system (about 9,600 acre-feet total). What this means is that through continued recharge project, you can double to quadruple the annual baseflow of the Umatilla River during the low summer and fall flow periods as compared to the present base-flow. The cool and high quality recharge water is a significant beneficial impact to the river system.
Ziari, Fred
Recurrent winter warming pulses enhance nitrogen cycling and soil biotic activity in temperate heathland and grassland mesocosms
NASA Astrophysics Data System (ADS)
Winter air temperatures are projected to increase in the temperate zone, whereas snow cover is projected to decrease, leading to more extreme soil temperature variability, and potentially to changes in nutrient cycling. Therefore, we applied six winter warming pulses by infra-red heating lamps and surface heating wires in a field experiment over one winter in temperate heathland and grassland mesocosms. The experiment was replicated at two sites, a colder mountainous upland site with high snow accumulation and a warmer and dryer lowland site. Winter warming pulses enhanced soil biotic activity for both sites during winter, as indicated by 35% higher nitrogen (N) availability in the soil solution, 40% higher belowground decomposition and a 25% increase in the activity of the enzyme cellobiohydrolase. The mobilization of N differed between sites, and the incorporation of 15N into leaves was reduced by 31% in response to winter warming pulses, but only at the cold site, with significant reductions occurring for three of four tested plant species at this site. Furthermore, there was a trend of increased N leaching in response to the recurrent winter warming pulses. Overall, projected winter climate change in the temperate zone, with less snow and more variable soil temperatures, appears important for shifts in ecosystem functioning (i.e. nutrient cycling). While the effects of warming pulses on plant N mobilization did not differ among sites, reduced plant 15N incorporation at the colder temperate site suggests that frost damage may reduce plant performance in a warmer world, with important implications for nitrogen cycling and nitrogen losses from ecosystems.
Schuerings, J.; Jentsch, A.; Hammerl, V.; Lenz, K.; Henry, H. A. L.; Malyshev, A. V.; Kreyling, J.
The Joint Winter Runway Friction Measurement Program
NASA Technical Reports Server (NTRS)
This paper provides background information, scope and objectives of a 5-year, Joint National Aeronautics & Space Administration (NASA)/Transport Canada (TC)/Federal Aviation Administration (FAA) Winter Runway Friction Measurement Program which has just completed its fourth winter season of testing. The test equipment, test sites, test results and accomplishments, the extent of the friction database compiled and future plans are described. The primary objective of this effort is to perform instrumented aircraft and ground vehicle tests aimed at identifying a "common number" that ground vehicle devices would report. This number denoted the International Runway Friction Index (IRFI) will be related to aircraft stopping performance. Several related studies are described including the effects of contaminant type on aircraft impingement drag and the effectiveness of various runway/aircraft chemical types and application rates. NASA considers the success of this program critical to insure adequate ground performance capability in adverse weather conditions for future aircraft as well as improving the safety of current aircraft ground operations.
Yager, Thomas J.
The embryonic shoot: a lifeline through winter.
The tiny vascular axis of the embryo emerges post-embryonically as an elaborate and critical infrastructure, pervading the entire plant system. Its expansive nature is especially impressive in trees, where growth and development continue for extended periods. While the shoot apical meristem (SAM) orchestrates primary morphogenesis, the vascular system is mapped out in its wake in the provascular cylinder, situated just below the emerging leaf primordia and surrounding the rib meristem. Formation of leaf primordia and provascular tissues is incompatible with the harsh conditions of winter. Deciduous trees of boreal and temperate climates therefore enter a survival mode at the end of the season. However, to be competitive, they need to maximize their growth period while avoiding cellular frost damage. Trees achieve this by monitoring photoperiod, and by timely implementation of a survival strategy that schedules downstream events, including growth cessation, terminal bud formation, dormancy assumption, acquisition of freezing tolerance, and shedding of leaves. Of central importance are buds, which contain an embryonic shoot that allows shoot development and elongation in spring. The genetic and molecular processes that drive the cycle in synchrony with the seasons are largely elusive. Here, we review what is known about the signals and signal conduits that are involved, the processes that are initiated, and the developmental transitions that ensue in a terminal bud. We propose that addressing dormancy as a property of the SAM and the bud as a unique shoot type will facilitate our understanding of winter dormancy. PMID:24368502
van der Schoot, Christiaan; Paul, Laju K; Rinne, P�ivi L H
Monitoring water phase dynamics in winter clouds
NASA Astrophysics Data System (ADS)
This work presents observations of water phase dynamics that demonstrate the theoretical Wegener-Bergeron-Findeisen concepts in mixed-phase winter storms. The work analyzes vertical profiles of air vapor pressure, and equilibrium vapor pressure over liquid water and ice. Based only on the magnitude ranking of these vapor pressures, we identified conditions where liquid droplets and ice particles grow or deplete simultaneously, as well as the conditions where droplets evaporate and ice particles grow by vapor diffusion. The method is applied to ground-based remote-sensing observations during two snowstorms, using two distinct microwave profiling radiometers operating in different climatic regions (North American Central High Plains and Great Lakes). The results are compared with independent microwave radiometer retrievals of vertically integrated liquid water, cloud-base estimates from a co-located ceilometer, reflectivity factor and Doppler velocity observations by nearby vertically pointing radars, and radiometer estimates of liquid water layers aloft. This work thus makes a positive contribution toward monitoring and nowcasting the evolution of supercooled droplets in winter clouds.
Campos, Edwin F.; Ware, Randolph; Joe, Paul; Hudak, David
Winter status of White-eyed Vireos in northeastern Louisiana
In December 2004, February 2005, and June 2005, we recaptured a White-eyed Vireo (Vireo griseus) that was banded on 19 May 2004 at the same location on the Tensas River National Wildlife Refuge, Madison Parish, LA. This is the first documented permanent resident White-eyed Vireo outside of resident populations known from Florida and southern Texas. This individual appears to be resident near the northern limit of the winter range for the species. Although White-eyed Vireos are uncommon in northeastern Louisiana during winter, we detected other White-eyed Vireos during line transect surveys and banding during winters 2003-2004 and 2004-2005. The lack of research and observation of winter birds in northern Louisiana and the secretive and inconspicuous behavior of White-eyed Vireos in winter may have led to an underestimation of abundance at the northern limits of their winter range.
Somershoe, S.G.; Twedt, D. J.
Food Preferences of Winter Bird Communities in Different Forest Types
Food availability for forest birds is a function of habitat type, forest management regime, and season. In winter, it is also impacted by variations in the weather. In the current study we assessed the food preferences of wild bird populations in two types of forest (spruce and beech) during the months of November 2010 to April 2011 in the Schw�bische Alb Biodiversity Exploratory, south-western Germany. Our aim was to investigate whether local bird communities preferred fat-rich, carbohydrate-rich or wild fruits and to determine how forest structure, seasonality and local weather conditions affected food preferences. We found higher bird activity in beech forests for the eleven resident species. We observed a clear preference for fat-rich food for all birds in both forest types. Snow cover affected activity at food stations but did not affect food preferences. Periods of extreme low temperatures increased activity.
Renner, Swen C.; Baur, Sofia; Possler, Astrid; Winkler, Julia; Kalko, Elisabeth K. V.; Bates, Paul J. J.; Mello, Marco A. R.
Winter Ecology of Kokanee: Implications for Salmon Management
We sampled various limnological parameters and measured growth and diet of age-0 kokanee Oncorhynchus nerka (lacustrine sockeye salmon) during two winters in a high-mountain lake of the Sawtooth Valley, Idaho. Although winter has been recognized as an important period for many warmwater fishes and for stream-dwelling salmonids, winter limitations have only recently been studied for coolwater and coldwater species. Ice
Geoffrey B. Steinhart; Wayne A. Wurtsbaugh
Vitamin D Supplementation and Immune Response to Antarctic Winter
NASA Technical Reports Server (NTRS)
Maintaining vitamin D status without sunlight exposure is difficult without supplementation. This study was designed to better understand interrelationships between periodic cholecalciferol(vitamin D3) supplementation and immune function in Antarctic workers. The effect of 2 oral dosing regimens of vitamin D3 supplementation on vitamin D status and markers of immune function were evaluated in people in Antarctica with no ultraviolet light exposure for 6 mo. Participants were given a 2,000-IU (50 g) daily (n=15) or 10,000-IU (250 g) weekly (n=14) vitamin D3 supplement for 6 mo during a winter in Antarctica. Biological samples were collected at baseline and at 3 and 6 mo. Vitamin D intake, markers of vitamin D and bone metabolism, and latent virus reactivation were determined. After 6 mo the mean (SD) serum 25-hydroxyvitamin D3 concentration increased from 56 plus or minus 17 to 79 plus or minus 16 nmol/L and 52 plus or minus 10 to 69 plus or minus 9 nmol/L in the 2,000-IU/d and 10,000-IU/wk groups (main effect over time P less than 0.001). Participants with a greater BMI (participant BMI range = 19-43 grams per square meter) had a smaller increase in 25-hydroxyvitamin D3 after 6 mo supplementation (P less than 0.05). Participants with high serum cortisoland higher serum 25-hydroxyvitamin D3 were less likely to shed Epstein-Barr virus in saliva (P less than 0.05). The doses given raised vitamin D status in participants not exposed to sunlight for 6 mo, and the efficacy was influenced by baseline vitamin D status and BMI. The data also provide evidence that vitamin D, interacting with stress, can reduce risk of latent virus reactivation during the winter in Antarctica.
Zwart, S. R.; Mehta, S. K.; Ploutz-Snyder, R.; Bourbeau, Y.; Locke, J. P.; Pierson, D. L.; Smith, Scott M.
Summer snow extent heralding of the winter North Atlantic Oscillation
NASA Astrophysics Data System (ADS)
Winter climate over the North Atlantic and European sector is modulated by the North Atlantic Oscillation (NAO). We find that the summer extent of snow cover over northern North America and northern Eurasia is linked significantly (p < 0.01) to the upcoming winter NAO state. Summers with high/low snow extent precede winters of low/high NAO index phase. We suggest the linkage arises from the summer snow-associated formation of anomalous longitudinal differences in surface air temperature with the subpolar North Atlantic. Our findings indicate the seasonal predictability of North Atlantic winter climate may be higher and extend to longer leads than thought previously.
Saunders, Mark A.; Qian, Budong; Lloyd-Hughes, Benjamin
Physical Properties of Normal Grade Biodiesel and Winter Grade Biodiesel
In this study, optical and thermal properties of normal grade and winter grade palm oil biodiesel were investigated. Surface Plasmon Resonance and Photopyroelectric technique were used to evaluate the samples. The dispersion curve and thermal diffusivity were obtained. Consequently, the variation of refractive index, as a function of wavelength in normal grade biodiesel is faster than winter grade palm oil biodiesel, and the thermal diffusivity of winter grade biodiesel is higher than the thermal diffusivity of normal grade biodiesel. This is attributed to the higher palmitic acid C16:0 content in normal grade than in winter grade palm oil biodiesel.
Sadrolhosseini, Amir Reza; Moksin, Mohd Maarof; Nang, Harrison Lau Lik; Norozi, Monir; Yunus, W. Mahmood Mat; Zakaria, Azmi
Differences in responses of summer and winter spinach to elevated UV-B at varying soil NPK levels.
Seasonal variations in response of spinach to elevated ultraviolet-B (UV-B) during summer and winter were assessed with respect to growth, biomass, yield, NPK uptake and NPK use efficiencies at varying NPK levels. The nutrient amendments were recommended NPK (RNPK) and 1.5 times recommended NPK (1.5 RNPK). Season significantly affected the measured parameters except the number of leaves. Under ambient UV-B, the growth performance of summer spinach was better in both the NPK levels, higher being at 1.5 RNPK leading to higher nutrient uptake. However, more reduction in biomass under elevated UV-B in 1.5 RNPK was recorded during summer, while during winter in RNPK. Reduction in biomass under elevated UV-B was accompanied by the modification in its partitioning with more biomass allocation to root during summer compared to winter at both the NPK levels. NPK uptake was higher in summer, while NPK use efficiencies were higher during winter. At higher than recommended NPK level, better NPK use efficiencies were displayed during both the seasons. Increased NPK supply during winter enabled spinach to capitalize light more efficiently and hence increased biomass accumulation. Strategies for surviving elevated UV-B in winter differ from those that provided protection from the same stress when it occurs in summer. PMID:24474564
Singh, Suruchi; Agrawal, Madhoolika; Agrawal, S B
Change in winter snow depth and its impacts on vegetation in China
NASA Astrophysics Data System (ADS)
Snow on land is an important component of the global climate system, but our knowledge about the effects of its change on vegetation is limited, particularly in temperate regions. In this study, we use daily snow depth data from 279 meteorological stations across China to investigate the distribution of winter snow depth (December - February) from 1980 to 2005 and its impact on vegetation growth, here approximated by satellite derived vegetation greenness index observations (NDVI). The snow depth trends show strong geographical heterogeneities. An increasing trend (> 0.01 cm yr-1) in maximum and mean winter snow depth is found north of 40 �N (e.g. Northeast China, Inner Mongolia, and Northwest China). A declining trend (< -0.01 cm yr-1) is observed south of 40 �N, particularly over Central and East China. The effect of changes in snow depth on vegetation growth was examined by ecosystem type. In desert, mean winter snow depth is significantly and positively correlated with NDVI during both early (May and June) and mid growing seasons (July and August), suggesting that winter snow plays a critical role in regulating desert vegetation growth, most likely through carry-over effects on soil moisture. In grassland, there is also a significant positive correlation between winter snow depth and NDVI in May-June. However, in forest, shrubland, and alpine meadow and tundra, no such correlation is found. These ecosystem-specific responses of vegetation growth to winter snow depth may be due to differences in growing environmental conditions such as temperature and rainfall.
Peng, Shushi; Piao, Shilong; Ciais, Philippe
[Effects of simulated warming on soil respiration in a cropland under winter wheat-soybean rotation].
This study was aimed to investigate the effects of simulated warming on soil respiration in a cropland under winter wheat-soybean rotation. Randomized experiments were carried out in the cropland. 6 Plots were arranged and there were 2 treatments, simulated warming and control. A portable soil CO2 fluxes system (LI-8100) was used to measure soil respiration rates. Soil CO2 production rates were determined by using a Barometric Process Separation (BaPS) method. Soil temperature and soil moisture were simultaneously determined when measuring soil respiration rates. Results indicated that soil respiration rates in different treatments showed similar seasonal variability, in accordance with the variability in soil temperature. Seasonal mean soil respiration rates for simulated warming and control treatments were 3.54 and 2.49 micromol x (m2 x s)(-1), respectively, during the winter wheat growth season, while they were 4.80 and 4.14 micromol x (m2 x s)(-1), respectively, during the soybean growth season. Simulated warming significantly (P < 0.05) enhanced soil respiration during both the winter wheat and soybean growth seasons. The impact of simulated warming on soil respiration was particularly obvious during the later growth stages of winter wheat (from heading to maturity stages) and soybean (from flowing to maturity stages). Further investigations suggested that, for both the winter wheat and soybean growth seasons, the relationship between soil respiration and soil temperature could be well explained (P < 0.01) by exponential functions. The temperature sensitivity (Q10) of soil respiration in the simulated warming treatments was significantly higher than that in the control treatments. The Q10 values for the simulated warming and control treatments were 1.83 and 1.26, respectively, during the winter wheat growth season, while they were 2.85 and 1.70, respectively, during the soybean growth season. This study showed that simulated warming significantly increased soil respiration in the cropland. PMID:23379143
Liu, Yan; Chen, Shu-Tao; Hu, Zheng-Hua; Ren, Jing-Quan; Shen, Xiao-Shuai
The History of Winter: teachers as scientists
NASA Astrophysics Data System (ADS)
The History of Winter (HOW) is a NASA Goddard Space Flight Center-funded teacher enrichment program that was started by Dr. Peter Wasilewski (NASA), Dr. Robert Gabrys (NASA) and Dr. Tony Gow (Cold Regions Research and Engineering Laboratory, or CRREL) in 2001 and continues with support and involvement of scientists from both the NASA Cryospheric Sciences Laboratory and CREEL. The program brings educators mostly from middle and high schools but also from state parks, community colleges and other institutions from across the US to the Northwood School (a small, private boarding school) in Lake Placid, NY for one week to learn about several facets of winter, polar, and snow research, including the science and history of polar ice core research, lake ice formation and structure, snow pack science, winter ecology, and remote sensing including current and future NASA cryospheric missions. The program receives support from the Northwood School staff to facilitate the program. The goal of the program is to create 'teachers as scientists' which is achieved through several hands-on field experiences in which the teachers have the opportunity to work with polar researchers from NASA, CRREL and partner Universities to dig and sample snow pits, make ice thin sections from lake ice, make snow shelters, and observe under-ice lake ecology. The hands-on work allows the teachers to use the same tools and techniques used in polar research while simultaneously introducing science concepts and activities to support their classroom work. The ultimate goal of the program is to provide the classroom teachers with the opportunity to learn about current and timely cryospheric research as well as to engage in real fieldwork experiences. The enthusiasm generated during the week-long program is translated into classroom activities with guidance from scientists, teachers and educational professionals. The opportunity to engage with polar researchers, both young investigators and renowned veterans in the field, is a unique experience for many of the teachers. Here we present lessons learned throughout the lifetime of the program, including successes and improvements made, and present our vision for the future of HOW.
Koenig, L.; Courville, Z.; Wasilewski, P. J.; Gow, T.; Bender, K. J.
Winter demand will bolster prices for fuel oil in the U. S
Demand for fuel oil will move up in the US this winter for the third straight year, largely on the strength of lower prices and increased economic activity. The weather, predicted to be only a little colder than last winter, will make a minor contribution to the demand increase. Natural gas consumption also will be up again this year. However, substantially higher gas prices will slow the rate of gain. Increased demand from the industrial sector will lead the way, with higher demand also expected from residential and commercial customers. Those increases will be somewhat offset by slightly lower demand among electric utilities, where demand will slip due to higher prices and fuel switching capability. The paper discusses demand and stocks for distillate fuels, residual fuel oil, and natural gas; refinery capacity and utilization; and prices.
Beck, R.J.
Diurnal flight time of wintering Canada geese: consideration of refuges and flight energetics
We monitored individual radio-equipped Canada geese (Branta canadensis) associated with a federal refuge to assess flight activities from late fall through spring. The number of flights per day was lowest in late fall when most geese remained within the refuge and highest in spring when they moved increasingly beyond the refuge area. The only significant seasonal difference in flight time occurred between late fall and late winter 1986. Over all seasons, diurnal flight time averaged 9.4 i?? 2.4 min (SE) and ranged from 0 to 33 min. Geese spent more time flying in afternoon periods during late winter 1986 and early winter 1987. Because of low goose populations on the refuge and abundant food resources in 1986-87, flight activity was probably lower than in most other years. Conservative estimates of average daily energy expenditures for flight ranged from 65 kJ/day in late fall to 200 kJ/day in early winter and were as high as 450 kJ/day. Additional energy costs for flight, when expressed as a percentage of daily energy expenditures, increased from fall (3%) to spring (10%). Highest estimates total daily energy costs (2987 kJ/day, equivalent to 178 g corn) appear to be within reasonable estimates of daily energy consumption. During periods of severe cold or limited food availability, however, additional energy demands for flight (e.g., due to disturbances or long foraging flights) may become important in the daily energy balance of individuals.
Austin, J. E.; Humburg, D. D.
Distribution Surge Arrester Failures due to Winter Lightning and Measurement of Energy Absorption Capability of Arresters
NASA Astrophysics Data System (ADS)
Surge arresters and distribution equipments with zinc-oxide elements are used for lightning protection of overhead power distribution lines in Japan. However, these surge arresters are sometimes damaged by direct lightning strokes, especially in winter. Increasing of surge arrester failures in winter is attributed to a very large electric charge of winter lightning than that of summer lightning. For improvement of surge arresters, we have measured the energy absorption capability of surge arresters using a half cycle of alternating current with a frequency of 50Hz for simulating a winter lightning current. The mean values of arrester failure energy increased in proportion to the volume of zinc-oxide element, however the values of arrester failure energy were quite uneven. We also have observed the aspects of damaged zinc-oxide elements, and have investigated the relationship between the arrester failure energy and the failure types of zinc-oxide elements. From these results, we suggest the improvement of the energy absorption capability of distribution surge arresters, especially for the uniform energy absorption capability.
Sugimoto, Hitoshi; Shimasaki, Katsuhiko; Kado, Hiroyuki
Spirit Scans Winter Haven (False Color)
NASA Technical Reports Server (NTRS)At least three different kinds of rocks await scientific analysis at the place where NASA's Mars Exploration Rover Spirit will likely spend several months of Martian winter. They are visible in this picture, which the panoramic camera on Spirit acquired during the rover's 809th sol, or Martian day, of exploring Mars (April 12, 2006). Paper-thin layers of light-toned, jagged-edged rocks protrude horizontally from beneath small sand drifts; a light gray rock with smooth, rounded edges sits atop the sand drifts; and several dark gray to black, angular rocks with vesicles (small holes) typical of hardened lava lie scattered across the sand. This view is a false-color rendering that combines images taken through the panoramic camera's 753-nanometer, 535-nanometer, and 432-nanometer filters.
Winter speed-up of ice flow at quiescent surge-type glaciers in Yukon, Canada
NASA Astrophysics Data System (ADS)
Glacier surge exhibits order-of-magnitude faster velocity and km-scale terminus advance during its short active phase after a long quiescent period. The observations of glacier surge are still limited, and the mechanisms of glacier surge cycle remain elusive. Moreover, with the exception of several well-examined glaciers, the glacier dynamics during their quiescent periods remains even more uncertain due to the paucity of surface velocity measurement data. Here we examined spatial-temporal changes in the ice surface velocity of surge-type glaciers in the St. Elias Mountains near the border of Alaska and Yukon during the period from December 2006 to March 2011. We applied the offset-tracking (feature-tracking) technique to the L-band synthetic aperture radar (SAR) images derived from the Japanese Advanced Land Observation Satellite (ALOS). The Chitina, Anderson, Walsh, and Logan Glaciers, the major subpolar surge-type glaciers of the Chitina River valley system, could be examined with the highest temporal resolution because of the overlap of multiple satellite tracks. We have found significant upstream accelerations from fall to winter at a number of glaciers during their quiescence. Moreover, whereas the upstream propagating summer speed-up was observed, the winter speed-up propagated from upstream to downglacier. Although the winter speed-up seems to be at odds with the well-known summer speed-up, these observations are consistent with the fragmentary but well-known fact of glacier surge that often initiates in winter, suggesting that some of the mechanisms would be valid even during quiescent phases. Ice surface velocity at mountain glaciers and ice sheets typically exhibits the greatest acceleration from spring to early summer, followed by deceleration in mid-summer to fall, and is slowest in winter. These short-term velocity changes are attributed to subglacial slip associated with water pressure changes that occur because of the seasonal variability of meltwater input, and the evolution of the englacial and subglacial hydrologic systems. Meltwater penetration to the bed in the early melt season enhances the basal water pressure in the subglacial drainage systems, lubricating the interface between the ice and the bed. As the meltwater flux increases further, the cavities grow as a result of frictional wall melting, and the water pressure is reduced, leading to slow down of surface velocities. Meanwhile, the initiation of glacier surge has been often observed in winter, which has been interpreted as an inefficient subglacial drainage system and subsequent high water pressure to trigger a surge. However, it has been uncertain how and where water can accumulate in winter. Because the examined surge-type glaciers are largely in sub-polar settings, the present findings of winter speed-up would further reinforce the paradoxical water storage problem in the surge triggering mechanism. The seasonal evolution of subglacial drainage systems and water pressure seems to have been modeled on the assumption of hard bed, which seems more difficult to store water in winter. One possible interpretation of the winter speed-up is, instead of accelerated sliding in winter, an enhanced deformation of subglacial till whose strength is weakened due to the higher pore-water pressure inside the till. We will discuss other speculations on the causes of the winter speed-up.
Furuya, M.; Abe, T.
The elusive gene for keratolytic winter erythema.
Keratolytic winter erythema (KWE), also known as Oudtshoorn skin disease, is characterised by a cyclical disruption of normal epidermal keratinisation affecting primarily the palmoplantar skin with peeling of the palms and soles, which is worse in the winter. It is a rare monogenic, autosomal dominant condition of unknown cause. However, due to a founder effect, it occurs at a prevalence of 1/7 200 among South African Afrikaans-speakers. In the mid-1980s, samples were collected from affected families for a linkage study to pinpoint the location of the KWE gene. A genome-wide linkage analysis, using microsatellite markers, identified the KWE critical region on chromosome 8p23.1-p22. Subsequent genetic studies focused on screening candidate genes in this critical region; however, no pathogenic mutations that segregated exclusively with KWE were identified. The cathepsin B (CTSB) and farnesyl-diphosphate farnesyltransferase 1 (FDFT1) genes revealed no potentially pathogenic variants, nor did they show differential gene expression in affected skin. Mutation detection in additional candidate genes also failed to identify the KWE-associated variant, suggesting that the causal variant may be in an uncharacterised functional region. Bioinformatic analysis revealed highly conserved regions within the KWE critical region and a custom tiling array was designed to cover this region and to search for copy number variation. Although the study did not identify a variant that segregates exclusively with KWE, it provided valuable insight into the complex KWE-linked region. Next-generation sequencing approaches are being used to comb the region, but the causal variant for this interesting hyperkeratotic palmoplantar phenotype still remains elusive.� PMID:24300638
Hull, Peter R; Hobbs, Angela; Aron, Shaun; Ramsay, Michele
Motor gasolines, winter 1981-1982
Analytical data for 905 samples of motor gasoline, were collected from service stations throughout the country and were analyzed in the laboratories of various refiners, motor manufacturers, and chemical companies. The data were submitted to the Bartlesville Energy Technology Center for study, necessary calculations, and compilation under a cooperative agreement between the Bartlesville Energy Technology Center (BETC) and the American Petroleum Institute (API). The samples represent the products of 30 companies, large and small, which manufacture and supply gasoline. These data are tabulated by groups according to brands (unlabeled) and grades for 17 marketing districts into which the country is divided. A map included in this report, shows marketing areas, districts and sampling locations. The report also includes charts indicating the trends of selected properties of motor fuels since winter 1959-1960 survey for the leaded gasolines, and since winter 1979-1980 survey for the unleaded gasolines. Sixteen octane distribution percent charts for areas 1, 2, 3, and 4 for unleaded antiknock index (R+M)/2 below 90.0, unleaded antiknock index (R+M)/2 90.0 and above, leaded antiknock index (R+M)/2 below 93.0, and leaded antiknock index (R+M)/2 93.0 and above grades of gasoline are presented in this report. The antiknock (octane) index (R+M)/2 averages of gasoline sold in this country were 87.4 for unleaded below 90.0, 91.7 for unleaded 90.0 and above, and 88.9 for leaded below 93.0. Only one sample was reported as 93.0 for leaded gasolines with an antiknock index (R+M)/2 93.0 and above.
Shelton, E M
Climate change impacts on spatial patterns in drought risk in the Willamette River Basin, Oregon, USA
Climate change is likely to lead more frequent droughts in the Pacific Northwest (PNW) of America. Rising air temperature will reduce winter snowfall and increase earlier snowmelt, subsequently reducing summer flows. Longer crop-growing season caused by higher temperatures will lead to increases in evapotranspiration and irrigation water demand, which could exacerbate drought damage. However, the impacts of climate change on
Il Won Jung; Heejun Chang
[Effects of farmland use type and winter irrigation on nitrate accumulation in sandy farmland soil].
With the sandy farmland in the marginal oasis in middle reaches of Heihe River Basin, Northwest China as test object, this paper studied soil NO3- -N accumulation and leaching under effects of different farmland use type and winter irrigation. The results showed that the mean NO3- -N concentration in 0-300 cm soil profile in different farmlands ranged from 1.27 mg x kg(-1) to 83.60 mg x kg(-1) Soil NO3- -N concentration was higher in 0-40 cm and 135-300 cm layers, but lower in 40-135 cm layer. Greenhouse vegetable field had a significantly higher soil NO3- -N concentration than the other farmland use types. The accumulated amount of soil NO3- -N decreased in the order of greenhouse vegetable field > tomato field > cotton field > seed maize field > maize-wheat rotation field > maize-wheat stripe intercropping field > alfalfa field > jujube plantation. The NO3- -N accumulation in 0-300 cm soil profile in greenhouse vegetable filed reached 2171.45 kg x hm(-2), which would be a serious menace to groundwater quality, followed by tomato field and cotton field. Lesser accumulation of soil NO3- -N was found in seed maize field, maize-wheat intercropping field, maize-wheat rotation field, alfalfa field, and jujube plantation, but its pollution potential would not be neglected. After winter irrigation, soil NO3- -N concentration decreased in 0-80 cm layer but increased in 80-300 cm layer, indicating that winter irrigation caused NO3- -N leaching into deeper soil depth. The leached amount of soil NO3- -N to deeper layers increased with increasing amount of winter irrigation. To mitigate soil NO3- -N leaching and groundwater contamination, a comprehensive consideration should be made on the rational arrangement of farmland use type, proper decrease of planting N-accumulated crops, and reasonable winter irrigation. PMID:19637601
Yang, Rong; Su, Yong-zhong
Climatic potential for tourism in the Black Forest, Germany � winter season
NASA Astrophysics Data System (ADS)
Climate change, whether natural or human-caused, will have an impact on human life, including recreation and tourism among other things. In this study, methods from biometeorology and tourism climatology are used to assess the effect of a changed climate on tourism and recreation in particular. The study area is the Black Forest mountainous region of south-west Germany, which is well known for its tourist and recreational assets. Climate model projections for the 2021-2050 period based on REMO-UBA simulations with a high spatial resolution of 10 km are compared to a 30-year reference period (1971-2000) using the IPCC emission scenarios A1B and B1. The results show that the mean winter air temperature will increase by up to 1.8�C, which is the most pronounced warming compared to the other seasons. The annual precipitation amount will increase marginally by 5% in the A1B scenario and 10% in the B1 scenario. Winter precipitation contributes about 10% (A1B) and 30% (B1) to variations in annual precipitation. Although the results show that winter precipitation will increase slightly, snow days affecting skiing will be reduced on average by approximately 40% due to regional warming. Cold stress will be reduced on average by up to 25%. The result is that the thermal environment will be advanced, and warmer winters are likely to lead to an upward altitudinal shift of ski resorts and winter sport activities, thus displacing land-use currently dedicated to nature conservation.
Endler, Christina; Matzarakis, Andreas
Snow cover and extreme winter warming events control flower abundance of some, but not all species in high arctic Svalbard
Abstract The High Arctic winter is expected to be altered through ongoing and future climate change. Winter precipitation and snow depth are projected to increase and melt out dates change accordingly. Also, snow cover and depth will play an important role in protecting plant canopy from increasingly more frequent extreme winter warming events. Flower production of many Arctic plants is dependent on melt out timing, since season length determines resource availability for flower preformation. We erected snow fences to increase snow depth and shorten growing season, and counted flowers of six species over 5�years, during which we experienced two extreme winter warming events. Most species were resistant to snow cover increase, but two species reduced flower abundance due to shortened growing seasons. Cassiope tetragona responded strongly with fewer flowers in deep snow regimes during years without extreme events, while Stellaria crassipes responded partly. Snow pack thickness determined whether winter warming events had an effect on flower abundance of some species. Warming events clearly reduced flower abundance in shallow but not in deep snow regimes of Cassiope tetragona, but only marginally for Dryas octopetala. However, the affected species were resilient and individuals did not experience any long term effects. In the case of short or cold summers, a subset of species suffered reduced reproductive success, which may affect future plant composition through possible cascading competition effects. Extreme winter warming events were shown to expose the canopy to cold winter air. The following summer most of the overwintering flower buds could not produce flowers. Thus reproductive success is reduced if this occurs in subsequent years. We conclude that snow depth influences flower abundance by altering season length and by protecting or exposing flower buds to cold winter air, but most species studied are resistant to changes. Winter warming events, often occurring together with rain, can substantially remove snow cover and thereby expose plants to cold winter air. Depending on morphology, different parts of the plant can be directly exposed. On this picture, we see Dryas octopetala seed heads from the previous growing season protrude through the remaining ice layer after a warming event in early 2010. The rest of the plant, including meristems and flower primordia, are still somewhat protected by the ice. In the background we can see a patch of Cassiope tetragona protruding through the ice; in this case, the whole plant including flower primordia is exposed, which might be one reason why this species experienced a loss of flowers the following season. Photograph by Philipp Semenchuk.
Semenchuk, Philipp R; Elberling, Bo; Cooper, Elisabeth J
Effect of canopy removal on snowpack quantity and quality, fraser experimental forest, Colorado
Snowpack peak water equivalent (PWE), ion concentration, content, and spatial distribution of ion load data from spring 1987-1996 in a 1 ha clearcut and adjacent forested plots vegetated by mature Picea engelmannii and Abies lasiocarpa in the Fraser experimental forest (FEF), Colorado are presented. Our objectives were: (1) to see if a forest opening might redistribute snowfall, snowpack moisture, and snowpack chemical content, and (2) to examine the importance of canopy interception on snowpack quantity and chemistry. On an average, the canopy intercepted 36% of snowfall. Interception was correlated with snowfall amount, snowpack PWE beneath the canopy, and air temperature. Canopy removal increased snowpack PWE to >90% cumulative snowfall inputs. Snowpack K-, H-, and NH4+ concentrations on the clearcut were lower and NO3- higher than in the snowpack beneath the forested plots. Cu mulative snowfall K+ input was less than in the clearcut snowpack; H+ inputs were greater in snowfall than in the snowpack of any plot; and inorganic N (NO3- and NH4+) inputs from snowfall to the clearcut were greater than to the forested plots. Processes accounting for the differences between snowfall inputs and snowpack ion content were leaching of organic debris in the snowpack, differential elution of the snowpack, and canopy retention. There were significant trends by year in snowpack ion content at PWE without similar trends in snowfall inputs. This finding coupled with snowpack ion elution bring into question the use of snowpack chemistry as an indicator of winter atmospheric inputs in short-term studies. ?? 2001 Elsevier Science B.V.
Stottlemyer, R.; Troendle, C. A.
Processes Controlling Water Vapor in the Winter Arctic Stratospheric Middleworld
NASA Technical Reports Server (NTRS)
Abstract: Water vapor in the winter arctic stratospheric middleworld (that part of the stratosphere with potential temperatures lower than the tropical tropopause) is important for two reasons: (1) the arctic middleworld is a source of air for the upper troposphere because of the generally downward motion, and thus its water vapor content helps determine upper tropospheric water, a critical part of the earth's radiation budget; and (2) under appropriate conditions, relative humidities will be large even to the point of stratospheric cirrus cloud formation, leading to the production of active chlorine species that could destroy ozone. On a number of occasions during SOLVE, clouds were observed in the stratospheric middleworld by the DC-8 aircraft. The relationship between ozone and CO from aircraft measurements taken during the early, middle and late part of the winter of 1999-2000 show that recent mixing with tropospheric air extends up to ozone values of about 350-450 ppbv. Above that level, the relationship suggests stratospheric air with minimal tropospheric influence. The transition is quite abrupt, particularly in early spring. Trajectory analyses are consistent with these relationships, with a significant drop-off in the percentage of trajectories with tropospheric PV values in their 10-day history as in-situ ozone increases above 400 ppbv. The water distribution is affected by these mixing characteristics, and by cloud formation. Significant cloud formation along trajectories occurs up to ozone values of about 400 ppbv during the early spring, with small, but nonzero probabilities extending to 550 ppbv. Cloud formation in the stratospheric middleworld is minimal during early and midwinter. Also important is the fact that, during early spring 30% of the trajectories near the tropopause (ozone values less than 200 ppbv) have minimum saturation mixing ratios less than 5 ppmv. Such parcels can mix out into the troposphere and could lead to very dry conditions in the upper troposphere at high latitudes during spring,
Pfister, Leonhard; Selkirk, Henry B.; Jensen, Eric J.; Podolske, James; Sachse, Glen; Avery, Melody; Schoeberl, Mark R.; Hipskind, R. Stephen (Technical Monitor)
Solar wind influence on atmosphere processes in winter Antarctica
NASA Astrophysics Data System (ADS)
. Galactic cosmic rays altered by the solar wind are traditionally regarded as the most plausible agent of the solar activity influence on the Earth's atmosphere. Meanwhile, it is well known that severe reductions in the galactic cosmic rays flux, known as Forbush decrease (FD), are caused by the solar wind of high speed and density, which sweeps the galactic cosmic rays on its way. Since the FD beginnings are registered at the Earth's orbit simultaneously with dramatic disturbances in the solar wind, the atmospheric effects, assigned to Forbush decreases, can be, in reality, result of the solar wind influence on the atmospheric processes. The paper presents the summary of the experimental results demonstrating the strong influence of the interplanetary electric field on atmospheric processes in the central Antarctica, where the large-scale system of vertical circulation is formed during the winter seasons. The influence is realized through acceleration of the air masses, descending into the lower atmosphere from troposphere, and formation of cloudiness above the Antarctic Ridge, where the descending air masses income into the surface layer. The acceleration is followed by sharp increase of the atmospheric pressure in the near-pole region, which gives rise to the katabatic wind strengthening above the entire Antarctica. The cloudiness formation is resulted in the sudden warmings in the surface atmosphere, since the cloud layer efficiently backscatters the long wavelength radiation going from the ice sheet, but does not affect the adiabatic warming process of the descending tropospheric air masses. When drainage flow strong strengthening the circumpolar vortex about the periphery of the Antarctic continent decays, the surface easterlies typical of the coast stations during the winter season are replaced by southerlies and the cold Antarctic air masses rush in the Southern ocean.
Troshichev, Oleg
Solar wind influence on atmospheric processes in winter Antarctica
NASA Astrophysics Data System (ADS)
Galactic cosmic rays (GCRs) altered by solar wind are traditionally regarded as the most plausible agent of solar activity influence on the Earth's atmosphere. However, it is well known that severe reductions in the GCRs flux, known as Forbush decreases (FDs), are caused by solar wind of high speed and density, which sweeps away the GCRs on its way. Since the FD beginnings are registered at the Earth's orbit simultaneously with dramatic disturbances in the solar wind, the atmospheric effects, assigned to FDs, can be, in reality, the results of the solar wind influence on the atmospheric processes. This paper presents a summary of the experimental results demonstrating the strong influence of the interplanetary electric field on atmospheric processes in central Antarctica, where the large-scale system of vertical circulation is formed during winter seasons. The influence is realized through acceleration of the air masses, descending into the lower atmosphere from the troposphere, and the formation of cloudiness above the Antarctic Ridge, where the descending air masses enter the surface layer. The acceleration is followed by a sharp increase of the atmospheric pressure near-pole region, which gives rise to the katabatic wind strengthening above the entire Antarctica. The cloudiness formation results in the sudden warmings in the surface atmosphere, since the cloud layer efficiently backscatters the long wavelength radiation from the ice sheet, but does not affect the adiabatic warming process of the descending tropospheric air masses. When the drainage flow strengthening the circumpolar vortex around the periphery of the Antarctic continent decays, the surface easterlies typical of the coast stations during the winter season are replaced by southerlies and the cold Antarctic air masses flow out to the Southern ocean.
Troshichev, O.
Winter Primer4 Ocean-Acoustic Dynamics and Energy Structures.
NASA Astrophysics Data System (ADS)
Solitary wave generation and propagation simulations are conducted with the Lamb(1994) nonhydrostatic model in conjunction with winter Primer4 data. The model simulation parameters are adjusted until the structures of the simulated wave packets compare favorably with the measured data, in period and amplitude. Acoustical field calculations are performed with a parabolic equation acoustical model alon