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Sea MARC II Investigation of the Norwegian-Greenland Sea.
National Technical Information Service (NTIS)
More than 80,000 sq km of SeaMARC II imagery was obtained in the northern Norwegian-Greenland Sea during October and November, 1989. Regions insonified included the Bjorneya Fan, a transect at 73 deg N from the continental margin to the Mohns Ridge, an al...
C. De Moustier
Characteristics for Extreme Sea States on the Norwegian Continental Shelf.
National Technical Information Service (NTIS)
The characteristics of extreme sea states on the Norwegian continental shelf are analyzed in terms of significant wave height and spectral peak period. Instrumental wave data from 6 different locations are used together with model data for wind and waves,...
K. Torsethaugen T. Faanes S. Haver
An operational search and rescue model for the Norwegian Sea and the North Sea
A new operational, ensemble-based search and rescue model for the Norwegian Sea and the North Sea is presented. The stochastic trajectory model computes the net motion of a range of search and rescue objects. A new, robust formulation for the relation between the wind and the motion of the drifting object (termed the leeway of the object) is employed. Empirically
Øyvind Breivik; Arthur A. Allen
Studies of the Norwegian Sea and North Atlantic.
National Technical Information Service (NTIS)
ONR grant N00014-91-J-1980 supported several collaborative field programs and related research on the marine geology and geophysics of the North Atlantic Ocean and Norwegian Sea by Hawaii Mapping Research Group (HMRG) of the University of Hawaii at Manoa,...
A. Shor
Carbon export by small particles in the Norwegian Sea
NASA Astrophysics Data System (ADS)
Despite its fundamental role in controlling the Earth's climate, present estimates of global organic carbon export to the deep sea are affected by relatively large uncertainties. These uncertainties are due to lack of observations as well as disagreement among methods and assumptions used to estimate carbon export. Complementary observations are thus needed to reduce these uncertainties. Here we show that optical backscattering measured by Bio-Argo floats can detect a seasonal carbon export flux in the Norwegian Sea. This export was most likely due to small particles (i.e., 0.2-20 ?m), was comparable to published export values, and contributed to long-term carbon sequestration. Our findings highlight the importance of small particles and of physical mixing in the biological carbon pump and support the use of autonomous platforms as tools to improve our mechanistic understanding of the ocean carbon cycle.
Dall'Olmo, Giorgio; Mork, Kjell Arne
Diatom flux and species composition in the Greenland Sea and the Norwegian Sea in 1991–1992
Vertical diatom fluxes were investigated in sediment trap material from June 1991 to July 1992 from the Greenland Sea at 72 °N, 007 °W and the Norwegian Sea at 70 °N, 000 °E in order to determine seasonal species compositions and alterations that affect settling assemblages. Different hydrographical conditions, including seasonal ice coverage, are reflected in seasonal variations of total
Alexander Kohly
Oil and gas bearing in Norwegian Sea basins
NASA Astrophysics Data System (ADS)
The Norwegian passive continental margin is represented by an extensive gentle shelf and continental slope. On the continental slope, there are the isolated Vøring, Møre and Ras basins, the Halten Terrace is situated to the east of them at the shelf, then the Nordland submarine ridge and the Trondelag Platform at the seaboard. There are Paleozoic, Mesozoic and Cenozoic sediments in its sections. Two complex structures are clearly distinguished in the sedimentary section: the lower stage (up to the Upper Cretaceous), reflecting the rifting structure of the basins, broken by a system of dislocations to a series of horsts, grabens, and separated blocks; and the upper stage, poorly dislocated, like a mantle covering the lower stage, with erosion and sharp unconformity. The Halten Terrace is the principal oil and gas production basin. At present, there are more than 50 oil, gas, and condensate fields in it. The following particularities have been discovered: than the field lays in the deepwater, than the age of the hydrocarbon pay is younger. It is also interesting that all gas fields are situated in the Vøring and Møre basins and western part of the Halten Terrace; the oil and gas fields, mainly at the center of the Halten Terrace; but pure oil fields, in the north of the terrace. In conformity with discovering the particularities, it is possible to say that the prospects of oil and gas bearing in the Norwegian Sea are primarilyt related to the Halten Terrace and the Vøring and Møre basins, especially the territories situated at the boundary of the two basins, where it is possible to discover large hydrocarbon accumulations like the Ormen-Lange field, because the Paleocene-Upper Cretaceous productive turbidite thick at the boundary of these basins is on the continental slope, which is considered promising a priori.
Zabanbark, A.
Upper layer cooling and freshening in the Norwegian Sea in relation to atmospheric forcing
NASA Astrophysics Data System (ADS)
Several time series in the Norwegian Sea indicate an upper layer decrease in temperature and salinity since the 1960s. Time series from Weather Station "M", from Russian surveys in the Norwegian Sea, from Icelandic standard sections, and from Scottish and Faroese observations in the Faroe-Shetland area have similar trends and show that most of the Norwegian Sea is affected. The reason is mainly increased freshwater supply from the East Icelandic Current. As a result, temperature and salinity in some of the time series were lower in 1996 than during the Great Salinity Anomaly in the 1970s. There is evidence of strong wind forcing, as the NAO winter index is highly correlated with the lateral extent of the Norwegian Atlantic Current. Circulation of Atlantic water into the western Norwegian and Greenland basins seems to be reduced while circulation of upper layer Arctic and Polar water into the Norwegian Sea has increased. The water-mass structure is further affected in a much wider sense by reduced deep-water formation and enhanced formation of Arctic intermediate waters. A temperature rise in the narrowing Norwegian Atlantic Current is strongest in the north.
Blindheim, J.; Borovkov, V.; Hansen, B.; Malmberg, S.-Aa.; Turrell, W. R.; Østerhus, S.
Inter-annual to decadal sea level variability along the Norwegian coast and in the Siberian Seas; a link with the Eastern North Atlantic
NASA Astrophysics Data System (ADS)
Inter-annual to decadal sea level variations from tide gauge records along the Norwegian coast and in the Siberian Seas are examined for the period 1950 to present. A combination of observations and theory is used to explore the physical mechanisms responsible for the observed sea level variability. Tide gauge records are first grouped into 6 geographical regions: the Norwegian Coast, the Barents Sea, the Kara Sea, the Laptev Sea, the East Siberian Sea, and the Chukchi Sea. Then an average of sea level at tide gauges is computed for each region. All regions exhibit large decadal sea level variations (up to 20 cm). Sea level corrected for the inverse barometer effect is significantly correlated with the Arctic Oscillation index in all regions except in the East Siberian and Chukchi Seas. There is a coherent sea level signal that affects a region extending from Southwest Norway to the Kara Sea. Previous studies have found that sea level variability at the Norwegian coast is related to variations in the Norwegian Atlantic Current (NwAC), which are mainly driven by changes in the wind forcing over the region. Here we show that, apart from the contribution of the NwAC and the local wind, there is an additional contribution to the sea level variability at the Norwegian coast resulting from the poleward propagation of wind-driven sea level variations along the continental slope of the Northeast Atlantic. The fact that sea level variability in both the Barents and the Kara Seas is highly coherent with that in the Norwegian coast suggests propagation of sea level variations further north into these regions. Eastward of the Kara Sea, where the continental shelf is shallower, sea level variations are much larger than in the other regions and they are highly correlated (~0.75) with the local longshore wind.he average of sea level at 8 tide gauge stations on the Norwegian coast (black line) and a reconstruction of sea level (blue line) using a combination of the tide gauge at Newlyn (on the eastern boundary of the North Atlantic) and the longshore wind over the Faroe-Shetland channel and the Norwegian continental shelf. The grey shaded area represents the uncertainty of the time series. A 2-year running mean has been applied to both time series.
Calafat, F. M.; Chambers, D. P.
Rock Physical study on an Upper-Palaeozoic Chert and Carbonate Interval in Wells from the Eastern Norwegian Barents Sea
Due to their general interest as hydrocarbon reservoir, the Upper Palaeozoic chert and carbonate interval in the Norwegian Barents Sea has been investigated from seismic data and well logs. We established a framework for geophysical well log analysis and reservoir characterization for the Finnmark Platform, an area situated in the South-Eastern part of the Norwegian Barents Sea. The interval is
A. Colpaert; J. Mienert; B. Fotland
Eemian cooling in the Norwegian Sea and North Atlantic ocean preceding continental ice-sheet growth
CHANGING conditions in the North Atlantic region may drive global climate changes1,2. According to previous reconstructions of the last interglacial (the Eemian), North Atlantic sea surface tempera-tures (SSTs) were similar to present-day values3. In the Norwegian Sea, even warmer conditions appeared as a single pulse of short duration4,5, whereas the Greenland ice record suggests that the warm interglacial air temperatures
E. Cortijo; J. C. Duplessy; L. Labeyrie; H. Leclaire; J. Duprat; T. C. E. van Wearing
Upper Cretaceous oceanic red bed foraminifera from the southern Norwegian Sea
NASA Astrophysics Data System (ADS)
Foraminiferal assemblages of Cretaceous Oceanic Red Beds (CORBs), which are geographically widespread and whose deposition reflects oligotrophic and well-oxygenated deep-water environments, have been described from the Atlantic, the Pacific and the Tethys. No detailed taxonomic study was, however, published on foraminifera from CORBs in the Norwegian Sea, though their existence was previously mentioned. This study, thus, investigates assemblages from a red sediment interval of the uppermost Santonian-middle Campanian Nise Formation in well 6306/5-1 drilled in the southern Norwegian Sea for taxonomy and their palaeoenvironmental implications based on morphogroup analysis. The assemblages are relatively highly diversified and composed of 61 deep-water agglutinated taxa without any calcareous forms. Biostratigraphically important Upper Cretaceous species, such as Caudammina gigantea and Uvigerinammina jankoi, are not recorded. The common occurrence of tubular forms, high diversity and the absence of small species of Upper Cretaceous abyssal fauna suggest a bathyal setting for the depositional environment of the CORBs in the Norwegian Sea. The absence of calcareous components indicates that they were deposited near or below the regional calcium carbonate compensation depth. The fauna from the red sediment interval shows similarity to both the mesotrophic flysch-type biofacies, for example in the presence of robust tubular forms and rzehakinids, and the CORB assemblages previously described in the abundant occurrence of infauna in environments with low flux of organic matter. This intermediate characteristics of the Norwegian CORB fauna is probably related to a shallower bathyal setting and higher flux of organic matter to the seafloor due to the proximity to land in a narrow proto-Norwegian Sea than abyssal and truly oligotrophic depositional environments of other CORBs. As sedimentation of CORBs can be regarded as the primary type of background hemipelagic sedimentation in deep-sea conditions, the CORB assemblages of this study may represent a background deep-sea foraminiferal assemblage of the Norwegian Sea, which was tectonically active during the Late Cretaceous and in which a thick unit of Upper Cretaceous turbidites was deposited.
Setoyama, Eiichi; Kaminski, Michael A.
Pelagic processes and vertical flux of particles: an overview of a long-term comparative study in the Norwegian Sea and Greenland Sea
Pelagic processes and their relation to vertical flux have been studied in the Norwegian and Greenland Seas since 1986. Results of long-term sediment trap deployments and adjoining process studies are presented, and the underlying methodological and conceptional background is discussed. Recent extension of these investigations at the Barents Sea continental slope are also presented. With similar conditions of input irradiation
B. von Bodungen; A. Antia; E. Bauerfeind; O. Haupt; W. Koeve; E. Machado; I. Peeken; R. Peinert; S. Reitmeier; C. Thomsen; M. Voss; M. Wunsch; U. Zeller; B. Zeitzschel
Saline outflow from the Arctic Ocean: Its contribution to the deep waters of the Greenland, Norwegian, and Iceland Seas
Since 1985 various investigators have proposed that Norwegian Sea deep water (NSDW) is formed by mixing of warm and saline deep water from the Arctic Ocean with the much colder and fresher deep water formed by convection in the Greenland Sea (GSDW). We here report on new observations which suggest significant modification and expansion of this conceptual model. We find
K. Aagaard; E. Fahrbach; J. Meincke; J. H. Swift
A study of oceanic surface heat fluxes in the Greenland, Norwegian, and Barents Seas
NASA Technical Reports Server (NTRS)
This study examines oceanic surface heat fluxes in the Norwegian, Greenland, and Barents seas using the gridded Navy Fleet Numerical Oceanography Central surface analysis and the First GARP Global Experiment (FGGE) IIc cloudiness data bases. Monthly and annual means of net and turbulent heat fluxes are computed for the FGGE year 1979. The FGGE IIb data base consisting of individual observations provides particularly good data coverage in this region for a comparison with the gridded Navy winds and air temperatures. The standard errors of estimate between the Navy and FGGE IIb winds and air temperatures are 3.6 m/s and 2.5 C, respectively. The computations for the latent and sensible heat fluxes are based on bulk formulas with the same constant heat exchange coefficient of 0.0015. The results show extremely strong wintertime heat fluxes in the northern Greenland Sea and especially in the Barents Sea in contrast to previous studies.
Hakkinen, Sirpa; Cavalieri, Donald J.
High Acidification Rate of Norwegian Sea Revealed by Boron Isotopes in the Deep-Sea Coral Madrepora Oculata
NASA Astrophysics Data System (ADS)
Ocean acidification and global warming due to the increase of anthropogenic CO2 are major threats for marine calcifying organisms, such as deep-sea corals, particularly in high-latitude regions. In order to evaluate the current anthropogenic perturbation and to properly assess the impacts and responses of calcifiers to previous changes in pH it is critical to investigate past changes of the seawater carbonate system. Unfortunately, current instrumental records of oceanic pH are limited, covering only a few decades. Scleractinian coral skeletons record chemical parameters of the seawater in which they grow. However, pH variability over multidecadal timescales remains largely unknown in intermediate and deep seawater masses. Here we present a study that highlights the potential of deep-sea-corals to overcome the lack of long-term pH records and that emphasizes a rapid acidification of high latitude subsurface waters of Norwegian Sea during the past decades. We have reconstructed seawater pH and temperature from a well dated deep-sea coral specimen Madrepora oculata collected alive from Røst reef in Norwegian Sea (67°N, 9°E, 340 m depth). This large branching framework forming coral species grew its skeleton over more than four decades determined using AMS 14C and 210Pb dating (Sabatier et al. 2012). B-isotopes and Li/Mg ratios yield an acidification rate of about -0.0030±0.0008 pH-unit.year-1 and a warming of 0.3°C during the past four decades (1967-2007). Overall our reconstruction technique agrees well with previous pH calculations (Hönisch et al., 2007 vs. Trotter et al., 2011 and McCulloch et al., 2012, i.e. the iterative method), but additional corrections are here applied using stable isotope correlations (O, C, B) to properly address kinetic fractionation of boron isotopes used for pH reconstruction. The resulting pH curve strongly anti-correlates with the annual NAO index, which further strengthens our evidence for the ocean acidification rate calculated here. If the rate of atmospheric CO2 emission is not reduced, the Røst reef will become undersaturated in aragonite by the end of century. Sabatier P. et al., 2012. Biogeosciences, 9, 1253-1265. Hönisch B. et al., 2007. Geochim. Cosmochim. Acta 71, 1636-1641. Trotter J. et al., 2011. Earth and Planetary Science Letters 303 (2011) 163-73. McCulloch M. et al., 2012. Geochim. Cosmochim. Acta 82, 154-162
Gonzalez, C.; Douville, E.; Hall-Spencer, J.; Montagna, P.; Louvat, P.; Gaillardet, J.; Frank, N.; Bordier, L.; Juillet-Leclerc, A.
New faunal and isotopic evidence on the late Weichselian—Holocene oceanographic changes in the Norwegian Sea
NASA Astrophysics Data System (ADS)
Downcore studies of planktonic and benthonic foraminifera and ? 18O and ? 13C in the planktonic foraminifer Neogloboquadrina pachyderma (sin.) in two piston cores from the southern part of the Norwegian Sea suggest large changes in the oceanic circulation pattern at the end of oxygenisotope stage 2 and in the early part of stage 1. Prior to oxygen-isotope Termination IA (16,000-13,000 yr B.P.), an isolated watermass with lower oxygen content and temperature warmer than today existed below a low salinity ice-covered surface layer in the Norwegian Sea. Close to Termination IA, well-oxygenated deep water, probably with positive temperatures, was introduced. This deep water, which must have had physical and/or chemical parameters different from those of present deep water in the Norwegian Sea, could have been introduced from the North Atlantic or been formed within the basin by another mechanism than that which forms the present deep water of the Norwegian Sea. A seasonal ice cover in the southern part of the Norwegian Sea is proposed for the period between Termination IA and the beginning of IB (close to 10,000 yr B.P.). The present situation, with strong influx of warm Atlantic surface-water and deep-water formation by surface cooling, was established at Termination IB.
Sejrup, Hans Petter; Jansen, Eystein; Erlenkeuser, Helmut; Holtedahl, Hans
Selective erosion by gravity flows in the deep-sea Lofoten Basin, Norwegian Sea
NASA Astrophysics Data System (ADS)
Deposits from gravity flows form a substantial part of the Lofoten Basin stratigraphy, a deep-water basin offshore Norway. This includes glacigenic debris flows from the shelf edge/upper slope, sandy turbidites from canyon - channel systems and debris flow deposits from submarine landslides. Little is, however, known about the properties of the gravity flows and their interaction with the sea floor sediments. We present newly acquired deep-towed side-scan sonar data co-registered with sub-bottom profiles showing small and large-scale irregularities of the sea floor in two areas relatively recently affected by gravity flows. The first area is located at about 2700 m water depth and is part of the distal Andøya Slide. Here, three several km wide and about 25 m thick lensoid and acoustically transparent deposits with a slightly irregular relief are inferred to represent debris flow deposits from submarine landslides originating from the nearby continental slope. The seafloor both below the debris flows and between and not affected by the debris flows is irregular due to closed seafloor depressions. They occur randomly and with a variety of forms up to 1 km across, 500 m wide and some meters deep. The second area is the Lofoten Basin Channel near its termination at about 3200 m water depth, beyond which laterally extensive sheets of normal graded sand interbedded with thinner mud layers occur. Sea floor depressions appear in several morphological forms on the channel flanks. The largest is more than 1 km long, up to 250 m wide, some meters deep has its longest axis parallel to the flow direction. It becomes less distinct in the down-flow direction. Other features in this area include densely spaced longitudinal features. In both areas the irregular sea floor morphology is inferred to be flute marks (or scours) formed by erosive gravity flows. Erosion of channel flanks by turbidity currents is well known from other studies but is not commonly described from the most distal channel settings as shown here. In the deepest part of the Lofoten Basin at least some of the flows overtopped and were erosive to the termination of the channel implying that the transition from erosion to deposition forming the sheets of sand occurred over a very short distance. The occurrence of flute marks in the area of the distal Andøya Slide indicates passage of spatially extensive and unconfined turbidity currents possibly associated with the slide event. The flows were accelerating or steadily flowing resulting in erosion and little or no deposition in part of the eastern Lofoten Basin. Acknowledgement This work is a contribution to the UNESCO program Training Trough Research and the Democen project (http://www.ig.uit.no/Democen/). We acknowledge the Research Council of Norway and Statoil for financial support. The Captain and crew of the Russian research vessel Professor Logachev provided essential support for the acquisition of data.
Sverre Laberg, Jan; Forwick, Matthias; Johannessen, Hilde B.; Ivanov, Mikhail; Kenyon, Neil H.; Vorren, Tore O.
Simulations of the mesoscale circulation of the Greenland-Iceland-Norwegian Seas
NASA Technical Reports Server (NTRS)
The Greenland, Iceland, and Norwegian Seas provide the only link between the North Atlantic and the Arctic Oceans. This is a very dynamic region, rich in mesoscale variability. A two-layer, hydrodynamic version of the Navy layered ocean model is used to simulate the mesoscale frontal features and associated current systems. The model is wind-driven using monthly mean wind stresses and inflow/outflow mass flux from the Arctic and North Atlantic Oceans. The current transports from the model results compare favorably with transport measurements from a number of observational experiments.
Heburn, George W.; Johnson, Clifford D.
Pelagic processes and vertical flux of particles: an overview of a long-term comparative study in the Norwegian Sea and Greenland Sea
NASA Astrophysics Data System (ADS)
Pelagic processes and their relation to vertical flux have been studied in the Norwegian and Greenland Seas since 1986. Results of long-term sediment trap deployments and adjoining process studies are presented, and the underlying methodological and conceptional background is discussed. Recent extension of these investigations at the Barents Sea continental slope are also presented. With similar conditions of input irradiation and nutrient conditions, the Norwegian and Greenland Seas exhibit comparable mean annual rates of new and total production. Major differences can be found between these regions, however, in the hydrographic conditions constraining primary production and in the composition and seasonal development of the plankton. This is reflected in differences in the temporal patterns of vertical particle flux in relation to new production in the euphotic zone, the composition of particles exported and in different processes leading to their modification in the mid-water layers. In the Norwegian Sea heavy grazing pressure during early spring retards the accumulation of phytoplankton stocks and thus a mass sedimentation of diatoms that is often associated with spring blooms. This, in conjunction with the further seasonal development of zooplankton populations, serves to delay the annual peak in sedimentation to summer or autumn. Carbonate sedimentation in the Norwegian Sea, however, is significantly higher than in the Greenland Sea, where physical factors exert a greater control on phytoplankton development and the sedimentation of opal is of greater importance. In addition to these comparative long-term studies a case study has been carried out at the continental slope of the Barents Sea, where an emphasis was laid on the influence of resuspension and across-slope lateral transport with an analysis of suspended and sedimented material.
von Bodungen, B.; Antia, A.; Bauerfeind, E.; Haupt, O.; Koeve, W.; Machado, E.; Peeken, I.; Peinert, R.; Reitmeier, S.; Thomsen, C.; Voss, M.; Wunsch, M.; Zeller, U.; Zeitzschel, B.
Changes in significant and maximum wave heights in the Norwegian Sea
NASA Astrophysics Data System (ADS)
This paper analyses 10 years of in-situ measurements of significant wave height (Hs) and maximum wave height (Hmax) from the ocean weather ship Polarfront in the Norwegian Sea. The 30-minute Ship-Borne Wave Recorder measurements of Hmax and Hs are shown to be consistent with theoretical wave distributions. The linear regression between Hmax and Hs has a slope of 1.53. Neither Hs nor Hmax show a significant trend in the period 2000-2009. These data are combined with earlier observations. The long-term trend over the period 1980-2009 in annual Hs is 2.72 ± 0.88 cm/year. Mean Hs and Hmax are both correlated with the North Atlantic Oscillation (NAO) index during winter. The correlation with the NAO index is highest for the more frequently encountered (75th percentile) wave heights. The wave field variability associated with the NAO index is reconstructed using a 500-year NAO index record. Hs and Hmax are found to vary by up to 1.42 m and 3.10 m respectively over the 500-year period. Trends in all 30-year segments of the reconstructed wave field are lower than the trend in the observations during 1980-2009. The NAO index does not change significantly in 21st century projections from CMIP5 climate models under scenario RCP85, and thus no NAO-related changes are expected in the mean and extreme wave fields of the Norwegian Sea.
Feng, Xiangbo; Tsimplis, M. N.; Yelland, M. J.; Quartly, G. D.
CO2 Storage Atlas Norwegian Sea - a case study from the Froan Basin
NASA Astrophysics Data System (ADS)
The CO2 storage atlas of the Norwegian Sea has been prepared by the Norwegian Petroleum Directorate at the request of the Ministry of Petroleum and Energy. The main objectives have been to identify the safe and effective areas for long-term storage of CO2 and to avoid possible negative interference with ongoing and future petroleum activity. We have built on the knowledge we have from the petroleum industry and from the two ongoing CO2 storage projects, Sleipner and Snøhvit, on the Norwegian Continental Shelf. Five aquifers and six prospects have been evaluated in terms of storage capacity and safe storage of CO2. One identified storage potential is the Froan Basin Garn and Ile Formations. The Froan Basin is a NE striking Jurassic syncline on the southwestern part of the Trøndelag Platform. The aquifers in the southeastern part of the Norwegian Sea typically have a consistent dip of 1-2 degrees from the Norwegian coast to the basinal areas. In the case of permeable beds occurring along the dip slope there is a risk that CO2 injected down dip can migrate up to where the aquifer is truncated by the Quaternary glacial sediments. A simulation study was performed in order to identify possible trapping mechanisms and to understand the timing and extent of long distance CO2 migration. The storage mechanisms considered were both structural and stratigraphic trapping. A simulation sector model of the Garn/Not/Ile Formations was build covering about 10% of the total expected communicating aquifer volume. The CO2 injection well was located down dip, but alternative locations and injection zones have been simulated, with different injection rates. The injection period is 50 years, and the migration of the CO2 plume was simulated and monitored for 10.000 years. CO2 will continue to migrate upwards as long as it is in free, movable state. Migration stops when CO2 is permanently bounded or trapped, by going into solution with the formation water or by being residually trapped, or becoming structurally trapped (mineralogical trapping not considered). Based on simulation results about 400 mill tons CO2 can be stored in the Garn and Ile aquifer (8 mill tons/year over 50 years). This will require 4 injection and give acceptable pressure increase (<20bar). Within 10000 years most of the gas will have gone into solution with the formation water or being residually trapped.
Sande Rød, Rita; Pham, Van T. H.
Characteristics and impact of a gale-force storm field over the Norwegian Sea
NASA Astrophysics Data System (ADS)
A unique data set was sampled by aircraft, ship, drift buoys and satellites in a strong storm event which occurred over the Norwegian Sea in March 2005 during the LOFZY field experiment. The atmospheric characteristics and the impact on the upper ocean are investigated. The storm field with winds up to 27 m s-1 was situated on the west-side of a low-pressure trough along the Norwegian coast and was marked by a sharp wind front. The entire system of trough, front and storm field was about 200 km wide, had a lifetime of 2 d in the area and advanced at 1-3 m s-1 SE-wards. Temperature contrast across the system was small, but wind contrast was remarkable and concentrated in a step-like front with 5-15 m s-1 difference over a distance of 3 km. The entire system was restricted to the lowest 2 km. It was accompanied by wide-spread rain and snow. Precipitation slightly surpassed evaporation (0.22 mm h-1). Surface heat fluxes amounted up to 400 W m-2. However, they cannot account for the observed sea surface temperature changes between -0.8 and +0.1 K within 6 h during the frontal passage. This is attributed to vertical mixing in the ocean caused by the frontal wind impact and superimposed to pre-existing mesoscale eddy circulations. The mixing acted on a temperature stratification in the uppermost 20-100 m which was opposite on both sides of the Norwegian Current.
Brümmer, Burghard; Müller, Gerd; Klepp, Christian; Spreen, Gunnar; Romeiser, Roland; Horstmann, Jochen
Norwegian 1990 sediment data for the North Sea Task Force (NSTF) and the Joint Monitoring Group (JMG).
National Technical Information Service (NTIS)
This report presents the 1990 sediment data compiled as part of the Norwegian contribution to the North Sea Task Force Monitoring Master Plan and the Joint Monitoring Programme (JMP). The JMP is ordered under the Oslo and Paris Commissions, which were est...
N. W. Green J. Klungsoeyr
Evaluation of Nimbus 7 SMMR sensor with airborne radiometers and surface observations in the Norwegian Sea
NASA Technical Reports Server (NTRS)
Measurements made by the Nimbus 7 SMMR are compared with near simultaneous observations using the airborne SMMR simulator and with surface observations. The area of the test is in the Norwegian Sea between Bear Island and Northern Norway. It is noted that during the observation period two low-pressure systems were located in the test area, giving a spatial wind variation from 3-20 m/s. It is shown that the use of the currently available brightness temperatures and algorithms for SMMR does not give universally satisfactory results for SST and wind speed under extreme weather conditions. In addition, the SMMR simulator results are seen as indicating the need for more work on calibration.
Gloersen, P.; Cavalieri, D.; Crawford, J.; Campbell, W. J.; Farrelly, B.; Johannessen, J.; Johannessen, O. M.; Svendsen, E.; Kloster, K.
Pleistocene glaciation history of the Northern North Sea and Norwegian Channel documented by basin-scale 3D seismic analysis
NASA Astrophysics Data System (ADS)
A regionally merged (c. 30,000 km2) 'megasurvey' 3D seismic dataset and an extensive set of 2D lines, tied to the Troll (89-03) core and wireline logs, was used to investigate the glacial and inter-glacial evolution of the northernmost North Sea through the Plio-Pleistocene. An extensive regional unconformity (URU) exists throughout the study area truncating the Naust Formation, a Plio-Pleistocene glacially-influenced progradational delta system, and older strata. This major erosion surface forms the base of the Norwegian Channel, a large (800 km long) cross-shelf trough located along the southern Norwegian coast. The evolution and exact erosion mechanism of this enigmatic feature is still debated. The stratigraphic succession above the URU consists of relatively flat-lying, alternating glacial and glacio-marine units of mid Pleistocene-Holocene age. This study is the first to present fully 3D seismic-constrained maps of the URU, the Naust clinoforms and all major glacial erosion surfaces within the Norwegian Channel infill. Furthermore it documents the geometries and sedimentary facies characteristics of the till and marine units preserved within the Norwegian Channel and the Norwegian sector of the Northern North Sea. Mapped erosional surfaces reveal a diverse assemblage of glacial morpologies interpreted as mega-scale glacial lineations, tunnel valleys, glaciotectonic thrust complexes, terminal moraines and meltwater conduits demarcating the terminus of successive grounded palaeo-ice sheets. Ice berg ploughing was common along the margin between 2.6 and 1.1 Ma with ice streaming commencing prior to 1.1 Ma. Repeated occupation of the NC by fast flowing ice streams, during the Elsterian, Saalian, and Weichselian (MIS 12, 10, 8, 6, 2), led to a progressively westward erosion of the channel margin, migrating approximately 60 km between 1.1 Ma and the LGM. Although well imaged by seismic data, the prolific record of glaciations and interglacials in the Northern North Sea require better age constraints to further fine tune the record of Pleistocene environmental changes. Whilst a large number of wells exist in the North Sea, giving basic lithological information, only very few have sufficiently detailed stratigraphic data in the Pleistocene section. Further research should thus include coring tied to high-resolution seismic data that can be linked to the basin-scale 3D seismic observations presented herein. As this study provides a unique insight into the spatial and temporal dynamics of shelf-edge glaciation in the northern North Sea and its Atlantic margin throughout the late Cenozoic, the plethora of features documented within the Northern North Sea may serve as a template for interpreting other less well imaged glaciated margins.
Huuse, J.; Huuse, M.
Water mass exchange between the North Atlantic and the Norwegian Sea during the past 28,000 years
THE Greenland, Iceland and Norwegian (GIN) seas are important regulators of heat transport in the Northern Hemisphere and of ocean-atmosphere CO2exchange1-5. Rapid changes in the circulation of surface and deep waters in this region may induce nonlinear climatic effects and climate instabilities2,3. Here we present carbon and oxygen isotope data that provide a record of circulation changes in the GIN
Terje Veum; Eystein Jansen; Maurice Arnold; Ida Beyer; Jean-Claude Duplessy
Benthic-pelagic coupling in the Greenland-Norwegian Sea and its effect on the geological record
The sedimentation pattern of organic material in the Greenland-Norwegian Sea is reflected in the surface sediments, although less than 0.5% of the organic matter is buried in the sediment. Maximum fluxes and benthic responses are observed during June and\\/or August\\/September, following the pattern of export production in the pelagial zone. The annual remineralization rate on the Vøring Plateau is 3.0
Gerhard Graf; Sebastian A. Gerlach; Peter Linke; Wolfgang Queisser; Will Ritzrau; Annette Scheltz; L. Thomsen; Ursula Witte
Gravity Inversion Predicts Sediment Thickness in the Norwegian-Greenland Sea
NASA Astrophysics Data System (ADS)
The Norwegian-Greenland Sea has formed by the Eurasia and Greenland plates separating across the Mohn and Knipovich ridges since the earliest Eocene. Whereas the Lofoten Basin on the Norwegian side is relatively well mapped by multi-channel (MCS) and wide-angle seismic data, few details are known about sediments in the Greenland and Boreas basins offshore Greenland. However, the gravity field of the entire sea is freely available from satellite altimetry, as is the bathymetry from the International Bathymetric Chart of the Arctic Ocean. We therefore explore the feasibility of using these gridded datasets along with prior geological knowledge in a 3-D prediction of sediment thickness beyond seismic calibration points. Although this problem is similar to other workers\\'{} predictions of bathymetry or crustal thickness, we find it difficult to separate the gravity signal of deep-ocean sediments from that of the underlying basement. Moreover, the thermal mantle structure beneath midocean ridges and continental margins is only in part compensated by the crustal topography, thus gravity modeling of only shallow surfaces may be misleading. We mitigate these problems by first assuming that the oceanic crust has constant density and thickness. Second, we approximate the thermal gravity field by the field calculated for a stack of 2-D finite-difference models of the seafloor spreading and cooling. The inversion is carried out by an iterative scheme where 1) the bottom of the sediment layer is calculated by damped downward continuation of the residual gravity; and 2) an updated residual is forward calculated from the Parker formula. The model space is further constrained by depths and density estimates from boreholes and an extensive velocity database. The maximum-likelihood solution predicts sediment basins on spatial scales greater than 20-25 km. It broadly agrees with existing MCS profiles in areas where the oceanic crust follows our assumptions, but is less accurate near seamounts and submarine ridges. We expect that our method can be used as a rapid 3-D exploration tool in frontier areas where seismic data are sparse due to logistic challenges or previous lack of commercial interest, notably in the Arctic Ocean.
Engen, O.; Wessel, P.; Faleide, J. I.; Frazer, N.
Norwegian Research Strategies on gas Hydrates and Natural Seeps in the Nordic Seas Region (GANS)
NASA Astrophysics Data System (ADS)
Continuous leakage of methane to the oceans from hydrate reservoirs that partially are exposed towards the seafloor is an increasing international concern, as the greenhouse gas methane is significantly more (c. 20 times) aggressive than CO2. In Norway we have research groups with interest and experience on natural seeps and gas hydrates. These features, and processes related to them, are challenging research targets which demands inputs from different fields if important research breakthroughs shall be made. In February 2004 deep sea researchers from the University of Tromso, Geological Survey of Norway, Norwegian Geotechnical Institute, Statoil and University of Bergen met to obtain an overview of the research effort in the fields of natural seeps and gas hydrates in Norway and to discuss national coordination, research strategies, research infrastructure and international co-operation. The following research strategies were agreed upon: i) Strengthen multidisciplinary research on deep sea systems, ii) develop a strategy for research on natural seeps and gas hydrates, iii) contribute in national coordination of research on natural seeps and gas hydrates, iv) Coordinate the use and development of research infrastructures important for research on natural seeps and gas hydrates, and v) contribute in the international evaluations of strategies for hydrate reservoir exploitation. Proposed research tasks for GANS include: i) Gas and gas hydrate formation processes and conditions for transport, accumulation, preservation and dissociation in sediments, ii) Effect of gas hydrate on physical properties of sediment, iii) Detection and quantification of in situ gas hydrate content and distribution pattern, iv) Effect of dissociation on soil properties, v) Gas hydrates as an energy resource, vi) Rapid methane release and climate change, and vii) Geohazard and environmental impact.
Hjelstuen, B. O.; Sejrup, H. P.; Andreassen, K.; Boe, R.; Eldholm, O.; Hovland, M.; Knies, J.; Kvalstad, T.; Kvamme, B.; Mienert, J.; Pedersen, R. B.
Salt distribution in the Norwegian-Danish Basin, Central North Sea
NASA Astrophysics Data System (ADS)
Salt tectonics have extensively been studied in most parts of the Central North Sea. However, few studies have been done in the Norwegian side of the Norwegian-Danish Basin. In this contribution, we report a new regional analysis of the salt patterns across the offshore Norwegian-Danish Basin. We have mapped the regional distribution of salt structures in the Norwegian-Danish Basin using both old and recent 2D seismic reflection profiles tied to wells. The salt-thickness map shows three distinct salt structures patterns: (1) NW-SE trending salt walls in the northern part of the basin; the spacing between the walls vary between 7 to 12 km; (2) a dense and irregular distribution of salt diapirs in the southern part of the studied area; (3) an irregular pattern of sparse but big salt diapirs in the eastern part of the basin. This domain is characterized by numerous turtle structures associated with salt diapirs. Reflection seismic cross-sections show that most salt structures only pierce the Triassic sedimentary strata whereas only few salt structures reach the seabed. Rotated fault blocks indicate a gliding vergence towards the South in the eastern part of the basin and towards the SE in the western side of the Norwegian-Danish Basin. No mature or compressive salt structures, except some squeezed salt diapirs, are observed in the topographic lows of the basin. The initiation of salt tectonics started during the early Middle Triassic in the entire basin; salt tectonics reactivations were recorded during the Middle Jurassic, Paleogene, and prior to the Quaternary but are not homogeneous across the basin. Salt movements inferred from our study are in good agreement with previous studies. The trend of salt walls (domain 1) indicates a NE-SW extension which is not compatible with N-S trending pre-salt faults. Instead, the strong Triassic subsidence towards the SW has most likely controlled the formation of the salt walls. The salt was initially thicker in domain 2 that also corresponds to the main depocenter of the first Triassic sequence. We suggest that both the salt thickness and the sedimentary differential loading, combined with the subsidence of the basin, have influenced the change of the salt pattern in domain 2. In domain 3, the reactivation of pre-salt faults might have triggered some of the salt structures. This area also received a large amount of sediments from the Skagerrak area during the Triassic subsidence, which may have influenced the distribution and evolution of salt diapirs and turtle structures. The combination of the different triggering processes and the different basin geometry of domain 3, which is bounded by highs to the South and North, in comparison to domain 2 which is open towards the Central Graben, are probably the key parameters that have controlled the salt pattern in this area. Finally, salt tectonics reactivations were likely controlled by the distribution of younger sediments and the successive tectonic regimes.
Sassier, Caroline; Jarsve, Erlend; Heeremans, Michel; Mansour Abdelmalak, Mohamed; Faleide, Jan Inge; Helge Gabrielsen, Roy
Disintegration of a marine-based ice stream - evidence from the Norwegian Channel, north-eastern North Sea
NASA Astrophysics Data System (ADS)
The Norwegian Channel Ice Stream repeatedly drained large part of the Fennoscandian Ice Sheet through Mid and Late Pleistocene glacial stages. During parts of Marine Isotope Stages 2 and 3, glacial ice from Fennoscandia and the British Isles coalesced in the central North Sea and the Norwegian Channel Ice Stream reached the shelf edge on multiple occasions. Through the last decades a large amount of acoustic and sediment core data have been collected from the Norwegian Channel, providing a good background for studies focussing on stability- and development-controlling parameters for marine-based ice streams, the retreat rate of the Norwegian Channel Ice Stream, and the behaviour of the Fennoscandian Ice Sheet. Further, this improved understanding can be used to develop more accurate numerical climate models and models which can be used to model ice-sheet behaviour of the past as well as the future. This study presents new acoustic records and data from sediment cores which contribute to a better understanding of the retreat pattern and the retreat rate of the last ice stream that occupied the Norwegian Channel. From bathymetric and TOPAS seismic data, mega-scale glacial lineations, grounding-zone wedges, and end moraines have been mapped, thereby allowing us to reconstruct the pro- and subglacial conditions at the time of the creation of these landforms. It is concluded that the whole Norwegian Channel was deglaciated in just over 1 000 years and that for most of this time the ice margin was located at positions reflected by depositional grounding-zone wedges. Further work will explore the influence of channel shape and feeding of ice from western Norwegian fjords on this retreat pattern through numerical modelling.
Morén, Björn M.; Petter Sejrup, Hans; Hjelstuen, Berit O.; Haflidason, Haflidi; Schäuble, Cathrina; Borge, Marianne
Structural evolution of the Norwegian-Greenland Sea: Results from detailed analysis of SeaMARC II side-scan sonar data
NASA Astrophysics Data System (ADS)
In 1989-1990, the SeaMARC II side-scan sonar (11-12 kHz) and swath bathymetric system imaged more than 80,000 kmsp2 of seafloor in the Norwegian-Greenland Sea and southern Arctic Ocean. The SeaMARC II reveals that the Knipovich Ridge is segmented into predominantly distinct elongate basins; the bathymetric to most slow spreading mid-ocean ridges. Present day segment discontinuities coincide with some of the ancient fracture zone faults which are also the locus of large scale volcanism. It is possible that intermittent ponding and leaking of volcanic material occurred along these pre-existing faults creating anomalous belts of shallow bathymetry that cross obliquely onto both flanks of the rift valley. The influence of pre-existing faults on the evolution of the Knipovich Ridge is the primary reason that the segment discontinuities, rather than the centers of the basinal segments are predominantly volcanic. This contrasts both the punctiform basin and dome segmentation patterns found along most other spreading centers. Off-axial ridge orientations of {˜}030sp° appear uniform on our SeaMARC II track between the Greenland Fracture Zone and the transitional zone of the Mohns-Knipovich system. This suggests that the ridges were formed under the stress of the Mohns and not the Knipovich Ridge. That these off-axial ridges occur along the entire northwestern flank of the Mohns Ridge up to the transition zone (Mohns-Knipovich bend) suggests that oblique spreading may not only be occurring across the Mohns Ridge, but additionally, substantial oblique spreading may also be occurring along the Knipovich Ridge. Using data obtained from the SeaMARC II side-scan sonar system, a model that may help explain the numerous geophysical anomalies of the eastern Norwegian-Greenland Sea is presented. Numerous seamount chains which obliquely cross the Knipovich Ridge and lie nearly parallel to its spreading direction are interpreted to be the result of magma upwelling into an ancient splinter faults associated with the Paleo-Spitsbergen Shear Zone. This model suggests that the Knipovich Ridge evolved through time by propagating from the south into the ancient Spitsbergen Shear Zone and was trapped in one or more of the complex fault systems associated with the paleo-shear zone.
Doss, Hany S.
Feedbacks of sedimentation on crustal heat flow - New insights from the Vøring Basin, Norwegian Sea
NASA Astrophysics Data System (ADS)
Information on the nature and origin of rift basins is preserved in the presently observed stratigraphy. Basin modeling aims at recovering this information with the goal of quantifying a basin's structural and thermal evolution. Decompaction and backstripping analysis is a classic and still popular approach to basin reconstruction [Steckler and Watts, 1978]. The total and tectonic subsidences, as well as sedimentation rates are calculated by the consecutive decompaction and removal of individual layers. The thermal history has to be computed separately using forward thermal models. An alternative is coupled forward modeling, where the structural and thermal history is computed simultaneously. A key difference between these reconstruction methods is that feedbacks of sedimentation on crustal heat flow are often neglected in backstripping methods. In this work we use the coupled basin modeling approach presented by Rüpke et al. [2008] to quantify some of the feedbacks between sedimentation and heat flow and to explore the differences between both reconstruction approaches in a case study from the Vøring Basin, Norwegian Sea. In a series of synthetic model runs we have reviewed the effects of sedimentation on basement heat flow. These example calculations clearly confirm the well-known blanketing effect of sedimentation and show that it is largest for high sedimentation rates. Recovery of sedimentation rates from the stratigraphy is, however, not straightforward. Decompaction-based methods may systematically underestimate sedimentation rates as sediment thickness is assumed to not change/thin during stretching. We present a new method for computing sedimentation rates based on forward modeling and demonstrate the differences between both methods in terms of rates and thermal feedbacks in a reconstruction of the Vøring basin (Euromargin transect 2). We find that sedimentation rates are systematically higher in forward models and heat flow is clearly depressed during times of high sedimentation. In addition, computed subsidence curves can differ significantly between backtripping and forward modeling methods. This shows that integrated basin modeling is important for improved reconstructions of sedimentary basins and passive margins. Rupke, L. H., et al. (2008), Automated thermotectonostratigraphic basin reconstruction: Viking Graben case study, AAPG Bulletin, 92(3), 309-326. Steckler, M. S., and A. B. Watts (1978), SUBSIDENCE OF ATLANTIC-TYPE CONTINENTAL-MARGIN OFF NEW-YORK, Earth and Planetary Science Letters, 41(1), 1-13.
Theissen, S.; Ruepke, L. H.
From conjugate volcanic rifted margins to micro-continent formation: Double breakup development of the Norwegian-Greenland Sea
NASA Astrophysics Data System (ADS)
We re-evaluate the structure and spreading evolution of the Norwegian-Greenland Sea and surrounding volcanic (rifted) margins based on new high-resolution aeromagnetic surveys. The new dataset combined with long-offset seismic and gravity data allow us to have a better understanding of the structure and evolution of the conjugate margin systems in the Norwegian-Greenland Sea from the rifting to the drifting stage. We particularly focus on the new JAS-12 aeromagnetic survey acquired between the Aegir Ridge and the Jan Mayen micro-continent, which was initially part of the Møre-Vøring-Greenland rift system. Combined with the previous NB-07 and JAS-05 surveys, our final compilation fully covers the continent-ocean transition and the whole oceanic spreading system from the Møre margin to the conjugate Jan Mayen micro-continent with high quality, high-resolution and reliable magnetic data. The new dataset allowed a new, consistent and precise interpretation of the magnetic polarity chrons and oceanic fractures, providing the basis for more accurate rotation poles estimation, and better basin and crustal reconstructions between Norway, Greenland and the Jan Mayen micro-continent. This dataset allowed us to clarify the pre- and post-breakup configurations of the rift system and discuss the mechanisms involved during the onset of the two phases of breakup leading to the micro-continent formation. Our observations and models suggest that the pre-breakup rift system evolved through a significant Late Jurassic-Cretaceous thinning phase. This episode led to a significant thinning of the continental crust and an exhumation of pre-existing lower crust. However, we have not been able to identify and/or validate any clear domains of exhumed and denudated serpentinised mantle. The first Eocene breakup is mostly characterised by severe magmatism (sill, SDRS). Lithospheric/asthenospheric processes leading to rift localisation do not necessarily represent a continuum of lithospheric deformation with the precedent thinning system. Diking and disconnected lithospheric plumbing are proposed to explain the Eocene breakup. After the first phase of continental breakup, two major phases of spreading influenced the Norwegian-Greenland Sea. Phase I (from C24 to C21r, ~54 to 49 Ma) marks the earliest phase of spreading, probably initiated in the central and outer part of the Møre Basin. During this period, the formation of overlapping systems and pseudo-fault development, indirectly influenced by the proto-margin segmentation, suggests the presence of additional micro-plates in the Norwegian-Greenland Sea. We also observed a significant change in the oceanic spreading system in the late Early Eocene. Based on observations from the surrounding areas, this supports a major and distinct tectonic and magmatic event in the Norwegian-Greenland Sea at around C21r (49-47.9 Ma), the beginning of a second phase. During Phase II, from C21r-C12 or possibly younger (48-<32 Ma) of the Norway Basin development, spreading rates decreased, spreading direction changed leading to the formation of unexpected N-S oriented oceanic fracture zones. Phase II probably coincides with the climax of extension and possibly local spreading that is suspected in the southern part of the Jan Mayen micro-continent forming a complex area of oceanic, transitional and continental fragments before its complete dislocation from East Greenland in Latest Oligocene.
Gernigon, Laurent; Blischke, Anett; Nasuti, Aziz; Olesen, Odleiv; Sand, Morten; Sveinn Arnarson, Thorarinn
Utilising borehole image logs to interpret delta to estuarine system: A case study of the subsurface Lower Jurassic Cook Formation in the Norwegian northern North Sea
The Lower Jurassic Cook Formation forms a regressive and transgressive sandstone wedge of shallow marine reservoir sandstones. It is distributed mainly in the Norwegian sector of the northern North Sea and the formation has proven to be hydrocarbon bearing. A case study of this formation from the Tampen Spur area presents a methodology for reconstructing depositional environments in areas of
Atle Folkestad; Zbynek Veselovsky; Paul Roberts
Rock Physical study on an Upper-Palaeozoic Chert and Carbonate Interval in Wells from the Eastern Norwegian Barents Sea.
NASA Astrophysics Data System (ADS)
Due to their general interest as hydrocarbon reservoir, the Upper Palaeozoic chert and carbonate interval in the Norwegian Barents Sea has been investigated from seismic data and well logs. We established a framework for geophysical well log analysis and reservoir characterization for the Finnmark Platform, an area situated in the South-Eastern part of the Norwegian Barents Sea. The interval is composed by approximately 600 m carbonate facies covered by a 60 m interval of spiculitic chert facies. The carbonate facies is characterized by lateral and vertical lithological variations including limestones, dolomites, evaporites and clastic material. The spiculitic interval exists in spiculitic chert and clay alternated with limestones. Data extends over an area with different palaeo environments from inner platform settings to continental slope and even basinal settings. Log curve data from four wells were processed through geophysical well log analysis using Powerlog and Matlab. Multi-well trend analysis was performed for a diagnostic modeling of the rock physical parameters. The examination of the variation of petrophysical properties, and how that variation transfers into the elastic domain is a key to the correlation of rock properties and the seismic attribute information. The final goal is to improve porosity and mineralogy predictions in pseudo-wells from 3D seismic data. The analyses of cross plots allow distinguishing several intervals which in certain cases correspond to individual stratigraphic units. The spiculite interval shows for example different rock types based on rock physics and these parameters can be linked with seismic. For the synthetic seismogram an s-wave velocity log has been modeled. We observed that for several lithological intervals such as the mixed limestone-dolomites and spiculites the Greenberg-Castagna model fitted the best, but for pure dolomite intervals the Krief model is more accurate. Furthermore, for the purest limestone the best fit was obtained for the differential effective medium equations. These intervals should be treated differently for obtaining the best fitting velocity-porosity relations.
Colpaert, A.; Mienert, J.; Fotland, B.
Sea Education Association (SEA)
NSDL National Science Digital Library
The Sea Education Association (SEA) in Woods Hole, MA provides undergraduates with an opportunity to participate in an academic study-abroad program called the SEA Semester. The program combines intensive research in the areas of oceanography, maritime studies, and nautical science with hands-on experience aboard a traditional sailing ship. Piloting, celestial navigation, and practical seamanship are learned together with oceanographic sampling techniques and marine laboratory procedures. Critical thinking, problem-solving, team-building and leadership skills are emphasized throughout the program. SEA Semester is appropriate for students in marine biology, geology and physical science, environmental studies, American studies, and most other areas within the liberal arts and sciences. Academic credit for SEA Semester is obtained through Boston University.
Seasonal increase in sea temperature triggers pancreas disease outbreaks in Norwegian salmon farms.
Pancreas disease (PD) is a viral disease causing negative impacts on economy of salmon farms and fish welfare. Its transmission route is horizontal, and water transport by ocean currents is an important factor for transmission. In this study, the effect of temperature changes on PD dynamics in the field has been analysed for the first time. To identify the potential time of exposure to the virus causing PD, a hydrodynamic current model was used. A cohort of salmon was assumed to be infected the month it was exposed to virus from other infective cohorts by estimated water contact. The number of months from exposure to outbreak defined the incubation period, which was used in this investigation to explore the relationship between temperature changes and PD dynamics. The time of outbreak was identified by peak in mortality based on monthly records from active sites. Survival analysis demonstrated that cohorts exposed to virus at decreasing sea temperature had a significantly longer incubation period than cohorts infected when the sea temperature was increasing. Hydrodynamic models can provide information on the risk of being exposed to pathogens from neighbouring farms. With the knowledge of temperature-dependent outbreak probability, the farmers can emphasize prophylactic management, avoid stressful operations until the sea temperature is decreasing and consider removal of cohorts at risk, if possible. PMID:23980568
Stene, A; Bang Jensen, B; Knutsen, O; Olsen, A; Viljugrein, H
NSDL National Science Digital Library
Sea World informational resource on all eight species of sea turtles. Excellent introduction to sea turtles including information on their classification, habitat, diet, reproduction, and much more. Includes photographs and illustrations throughout. Features two teaching activities for grades K-2.
Diet, an independent determinant for plasma total homocysteine. A cross sectional study of Norwegian workers on platforms in the North Sea
Objective: To examine whether diet is an independent determinant for total homocysteine (tHcy) levels.Design: Data on background variables was collected by questionnaire interviews, food intake by one 24 h recall and tHcy levels in a blood sample in 310 healthy men (mean age, 38 y).Setting: Two oil producing platforms in the Norwegian sector in the north sea.Results: The arithmetic mean
A Oshaug; KH Bugge; H Refsum
Effects of bottom water warming and sea level rise on Holocene hydrate dissociation and mass wasting along the Norwegian-Barents Continental Margin
Gas hydrate (GH) stability modeling results explain why some major Holocene submarine landslides along the Norwegian-Barents margin could have been triggered by GH dissociation during the early to middle Holocene, not during the lowest sea levels of the Last Glacial Maximum (LGM). Our model results show that subbottom depths of 170–260 m below the pre-slide continental slope (ca. 350–475 m
Woo-Yeol Jung; Peter R. Vogt
Contemporary ocean warming and freshwater conditions are related to later sea age at maturity in Atlantic salmon spawning in Norwegian rivers
Atlantic salmon populations are reported to be declining throughout its range, raising major management concerns. Variation in adult fish abundance may be due to variation in survival, growth, and timing of life history decisions. Given the complex life history, utilizing highly divergent habitats, the reasons for declines may be multiple and difficult to disentangle. Using recreational angling data of two sea age groups, one-sea-winter (1SW) and two-sea-winter (2SW) fish originated from the same smolt year class, we show that sea age at maturity of the returns has increased in 59 Norwegian rivers over the cohorts 1991–2005. By means of linear mixed-effects models we found that the proportion of 1SW fish spawning in Norway has decreased concomitant with the increasing sea surface temperature experienced by the fish in autumn during their first year at sea. Furthermore, the decrease in the proportion of 1SW fish was influenced by freshwater conditions as measured by water discharge during summer months 1 year ahead of seaward migration. These results suggest that part of the variability in age at maturity can be explained by the large-scale changes occurring in the north-eastern Atlantic pelagic food web affecting postsmolt growth, and by differences in river conditions influencing presmolt growth rate and later upstream migration.
Otero, Jaime; Jensen, Arne J; L'Abee-Lund, Jan Henning; Stenseth, Nils Chr; Storvik,, Geir O; V?llestad, Leif Asbj?rn
Summer distribution and ecological role of seabirds and marine mammals in the Norwegian and Greenland seas (June 1988)
NASA Astrophysics Data System (ADS)
During the ARK V /2 expedition of RV Polarstern in the Norwegian and Greenland seas in June 1988, 380 half hour counts for marine vertebrates (seabirds, pinnipeds and cetaceans) were carried out. Results are presented as total numbers encountered and then converted into density and food intake. Mean food intake was 2.2 kg fresh weight per km 2 per day for seabirds, with a higher value in Atlantic water (2.5) lower values in polar water and the pack ice (1.7 and 1.9), and an intermediate value at the ice edge. The main species were the alcids (1.5, primarily Little Auk, Alle alle and Brünnich's Guillemot, Urea Iomvia) ,the Fulmar, Fulmarus glacialis (0.5), and the Kittiwake, Rissa tridactyla (0.2). The ecological role of cetaceans was clearly lower, with a mean value of 0.2 and a maximum of 0.7 in Atlantic water (rough evaluation, due to the low number of contacts). The food intake by pinnipeds was 0.55 kg/km 2 day at the ice edge and 0.4 in the pack ice; they were mainly harp, Phoca groenlandica and hooded seals, Cystophora cristata, in one main concentration each and ringed seals, Phoca hispida, scattered on the pack. Data for July 1988 show a great similarity with these results, except for a lower density of alcids, which probably reflects that Little Auk, Brünnich's Guillemot and Common Guillemot, Uria aalge already had started to leave the region.
Joiris, Claude R.
Benthic-pelagic coupling in the Greenland-Norwegian Sea and its effect on the geological record
NASA Astrophysics Data System (ADS)
The sedimentation pattern of organic material in the Greenland-Norwegian Sea is reflected in the surface sediments, although less than 0.5% of the organic matter is buried in the sediment. Maximum fluxes and benthic responses are observed during June and/or August/September, following the pattern of export production in the pelagial zone. The annual remineralization rate on the Vøring Plateau is 3.0 g C m-2 a -1 Freshly settled phytodetritus, as detected by chlorophyll measurements, is rapidly mixed into the sediment and decomposed. It stimulates the activity of benthic organisms, especially foraminifera. The mixing coefficient for this material is D b=0.2 cm2 d-1, which is two to three orders of magnitude higher than that estimated from radiotracer methods. The effect on the geological record, however, is likely to be small. Chlorophyll-containing particles are at first very evenly distributed on the seafloor. After partial decomposition and resuspension, a secondary redistribution of particles occurs which can result in the formation of a high accumulation area, with an up to 80-fold increase in the sedimentation rate by lateral advection. This is mainly due to physical processes, because biodeposition mediated by benthic animals increases sedimentation by only a factor of two or three.
Graf, Gerhard; Gerlach, Sebastian A.; Linke, Peter; Queisser, Wolfgang; Ritzrau, Will; Scheltz, Annette; Thomsen, L.; Witte, Ursula
Distribution of anaerobic methane-oxidizing and sulfate-reducing communities in the G11 Nyegga pockmark, Norwegian Sea.
Pockmarks are seabed geological structures sustaining methane seepage in cold seeps. Based on RNA-derived sequences the active fraction of the archaeal community was analysed in sediments associated with the G11 pockmark, in the Nyegga region of the Norwegian Sea. The anaerobic methanotrophic Archaea (ANME) and sulfate-reducing bacteria (SRB) communities were studied as well. The vertical distribution of the archaeal community assessed by PCR-DGGE highlighted the presence of ANME-2 in surface sediments, and ANME-1 in deeper sediments. Enrichments of methanogens showed the presence of hydrogenotrophic methanogens of the Methanogenium genus in surface sediment layers as well. The active fraction of the archaeal community was uniquely composed of ANME-2 in the shallow sulfate-rich sediments. Functional methyl coenzyme M reductase gene libraries showed that sequences affiliated with the ANME-1 and ANME-3 groups appeared in the deeper sediments but ANME-2 dominated both surface and deeper layers. Finally, dissimilatory sulfite reductase gene libraries revealed a high SRB diversity (i.e. Desulfobacteraceae, Desulfobulbaceae, Syntrophobacteraceae and Firmicutes) in the shallow sulfate-rich sediments. The SRB diversity was much lower in the deeper section. Overall, these results show that the microbial community in sediments associated with a pockmark harbour classical cold seep ANME and SRB communities. PMID:21751028
Lazar, Cassandre Sara; Dinasquet, Julie; L'Haridon, Stéphane; Pignet, Patricia; Toffin, Laurent
Freshwater outflow of the Baltic Sea and transport in the Norwegian current: A statistical correlation analysis based on a numerical experiment
NASA Astrophysics Data System (ADS)
Based on the results of a numerical ocean model, we investigate statistical correlations between wind forcing, surface salinity and freshwater transport out of the Baltic Sea on one hand, and Norwegian coastal current freshwater transport on the other hand. These correlations can be explained in terms of physics and reveal how the two freshwater transports are linked with wind forcing, although this information proves to be non-sufficient when it comes to the dynamics of the Norwegian coastal current. Based on statistical correlations, the Baltic Sea freshwater transport signal is reconstructed and shows a good correlation but a poor variability when compared with the measured signal, at least when data filtered on a two-daily time scale is used. A better variability coherence is reached when data filtered on a weekly or monthly time scale is used. In the latest case, a high degree of precision is reached for the reconstructed signal. Using the same kind of methods for the case of the Norwegian coastal current, the negative peaks of the freshwater transport signal can be reconstructed based on wind data only, but the positive peaks are under-represented although some of them exist mostly because the meridional wind forcing along the Norwegian coast is taken into account. Adding Norwegian coastal salinity data helps improving the reconstruction of the positive peaks, but a major improvement is reached when adding non-linear terms in the statistical reconstruction. All coefficients used to re-construct both freshwater transport signals are provided for use in European Shelf or climate modeling configurations.
Hordoir, Robinson; Dieterich, Christian; Basu, Chandan; Dietze, Heiner; Meier, H. E. M.
Phytoplankton production and growth regulation in the Subarctic North Atlantic: A comparative study of the Labrador Sea-Labrador/Newfoundland shelves and Barents/Norwegian/Greenland seas and shelves
NASA Astrophysics Data System (ADS)
A study was made of phytoplankton (distribution, phenology, physiology, productivity and community composition) and environment properties that influence their growth (light and nutrients) comparing the western Subarctic Atlantic (Labrador Sea, Labrador/Newfoundland shelves) with the eastern Subarctic (Barents, Norwegian and Greenland Seas and shelves) and drawing on ship-based observations, satellite ocean colour data (SeaWiFS) and output from a 3D coupled ecosystem-ocean circulation model, covering the last 15-25 yrs. Similarities between regions were seen in geographic variability (e.g. latitudinal gradients), seasonal cycles and magnitude of phytoplankton biomass and productivity, and community composition. Regional differences were related to geographic location, presence/absence of ice, seasonal mixing, source waters (Arctic versus Atlantic) and nutrient supply, and response to atmospheric forcing. With regard to the latter, most of the observations considered in this study cover the recent period of rapid warming and the historical out-of-phase response (e.g. ice conditions, air and ocean temperatures, hydrography) of the western and eastern Subarctic Atlantic to atmospheric forcing is no longer apparent. Observations and modelling looking back over the last two decades suggest that the timing of the spring bloom and peak seasonal productivity are occurring progressively earlier in the year, particularly at high latitudes in both the western and eastern Subarctic. Climate change (ocean warming) is projected to increase overall phytoplankton productivity in the Subarctic Atlantic and will be manifest particularly in ice-influenced regions Labrador/Newfoundland Shelves, Barents/Greenland Seas and shelves and regions where Arctic outflow and Atlantic inflow influence phytoplankton dynamics. Northward movement of Atlantic waters as a result of climate change, manifest earliest in the eastern Subarctic (Norwegian/Barents Seas) will displace cold-water phytoplankton species with warm-water species and shift community transitions zones farther north in the coming decades.
Glen Harrison, W.; Yngve Børsheim, K.; Li, William K. W.; Maillet, Gary L.; Pepin, Pierre; Sakshaug, Egil; Skogen, Morten D.; Yeats, Philip A.
Caprock integrity for offshore CO2 storage in the Norwegian North Sea - Seismic investigation of a soft sediment seafloor fracture
NASA Astrophysics Data System (ADS)
The Utsira formation (fm) below the Norwegian North Sea is a promising candidate for CCS due to its big expanse, the relatively easy accessibility and its physical properties, like high porosity and permeability. Situated only about 900m below the seafloor, caprock integrity is a more crucial issue than in deeper lying storage candidates. Earlier studies determined a thick shale layer on top of the Utsira fm, especially in and around the area that presently is used to store CO2. This is also confirmed by the monitoring techniques used to ensure that CO2 stays in the subsurface. The Hugin Fracture that was discovered in 2011 above the northern part of the Utsira fm is leaking methane-enriched ancient glacial melt water and may question the overall quality of the caprock seal. In this study, we present recent high-resolution near-offset conventional 3D seismic of an area of about 980km^2 around the fracture as well as high-frequency shallow 2D-seismic lines. We investigate how far the fracture reaches into the subsurface, whether it is connected to other structures that may serve as fluid pathway at least for glacial meltwater and if there is any sign of a fluid migration pathway to the deep subsurface, i.e. the Utsira fm. Preliminary results show that the Hugin Fracture itself can be traced down to about 50m or 184ms TWT. The fracture is situated above one of many buried tunnel valleys that are criss-crossing the study area in the topmost 500ms TWT of the seismic cube. In addition, there are numerous very shallow bright spots indicating gas pockets, with unknown source of the gas, i.e. biogenic or thermogenic. Some of these bright spots seem to be connected to tunnel valleys or fractures. Our preliminary results calls for a more thorough investigation of the shallow subsurface, especially above the Utsira fm, prior to starting large-scale CCS. A HiSAS reflection image of the seafloor expression of the Hugin Fracture, discovered on a UiB-led cruise in June 2011. It is located in Norwegian block 16/4, 25 km north of an operational offshore CO2 injection site.
Landschulze, K.; Pedersen, R. B.
Recovery of Benthic Megafauna from Anthropogenic Disturbance at a Hydrocarbon Drilling Well (380 m Depth in the Norwegian Sea)
Recovery from disturbance in deep water is poorly understood, but as anthropogenic impacts increase in deeper water it is important to quantify the process. Exploratory hydrocarbon drilling causes physical disturbance, smothering the seabed near the well. Video transects obtained by remotely operated vehicles were used to assess the change in invertebrate megafaunal density and diversity caused by drilling a well at 380 m depth in the Norwegian Sea in 2006. Transects were carried out one day before drilling commenced and 27 days, 76 days, and three years later. A background survey, further from the well, was also carried out in 2009. Porifera (45% of observations) and Cnidaria (40%) dominated the megafauna. Porifera accounted for 94% of hard-substratum organisms and cnidarians (Pennatulacea) dominated on the soft sediment (78%). Twenty seven and 76 days after drilling commenced, drill cuttings were visible, extending over 100 m from the well. In this area there were low invertebrate megafaunal densities (0.08 and 0.10 individuals m?2) in comparison to pre-drill conditions (0.21 individuals m?2). Three years later the visible extent of the cuttings had reduced, reaching 60 m from the well. Within this area the megafaunal density (0.05 individuals m?2) was lower than pre-drill and reference transects (0.23 individuals m?2). There was a significant increase in total megafaunal invertebrate densities with both distance from drilling and time since drilling although no significant interaction. Beyond the visible disturbance there were similar megafaunal densities (0.14 individuals m?2) to pre-drilling and background surveys. Species richness, Shannon-Weiner diversity and multivariate techniques showed similar patterns to density. At this site the effects of exploratory drilling on megafaunal invertebrate density and diversity seem confined to the extent of the visible cuttings pile. However, elevated Barium concentration and reduced sediment grain size suggest persistence of disturbance for three years, with unclear consequences for other components of the benthic fauna.
Gates, Andrew R.; Jones, Daniel O. B.
The 3rd EMBO Conference on, "Autophagy: Molecular mechanism, physiology and pathology" organized by Anne Simonsen and Sharon Tooze, was held in May 2013 on a sea cruise along the Norwegian coastline from Bergen to Tromsø. Researchers from all corners of the world presented work covering autophagosome biogenesis, physiological regulation of autophagy, selective autophagy and disease. PMID:23917436
Martens, Sascha; Rusten, Tor Erik; Kraft, Claudine
NSDL National Science Digital Library
The sea urchin is a type of echinoderm. It is a consumer because it cannot make its own food and must eat other organisms to get energy. Sea urchins are omnivores, meaning they eat both plants and other animals to gain energy. Sea urchins have been known to eat algae, mussels, and sponges.
N/A N/A (NOAA;Channel Islands National Marine Sanctuary)
article title: The Red Sea View Larger Image ... Multi-angle Imaging SpectroRadiometer (MISR) image of the Red Sea was acquired on August 13, 2000. Located between the East African coast and the Saudi Arabian peninsula, the Red Sea got its name because the blooms of a type of algae, Trichodesmium ...
The Barents Sea is situated on the continental shelf between Norway, the Spitsbergen Islands, and Novaya Zemlya. The main structural framework of the area was formed during the Caledonian and Hercynian orogenies, whereas the western parts were reactivated by the Kimmerian and Alpine orogenies. Because of the complex opening of the Greenland Norwegian Sea, important tertiary reactivation of Mesozoic normal faults occurred along southwest-northeast-trending systems of wrench faults. Owing to substantial erosion in the late Tertiary, the subsidence history and thermal development are more difficult to unravel in this area than in other places along the Norwegian Shelf. The erosion products were deposited in a huge sedimentary wedge extending onto the oceanic crust. The hydrocarbon discoveries in the Troms area in the southern part of the Barents Sea are encouraging for further exploration. However, the petroleum potential for large areas is not well known at this stage.
Riis, F.; Vollset, J.
NASA Astrophysics Data System (ADS)
We investigate sea level change and variability in the Arctic region over the 1950-2009 time span. Analysis of >60 long tide gauge records available since 1950 along the Norwegian and Russian sectors shows that coastal mean sea level was almost stable until about 1980 but since then displayed a clear increasing trend. In fact until the mid-1990s, the mean sea level closely followed the Arctic Oscillation (AO) index variations. However, since about 1995, the mea sea level curve departs from the AO influence and presents a large increasing trend of ~ 4 mm/yr. Using in situ ocean temperature data down to 700 m (from the WOD09 and JAMSTEC data bases), we estimated the thermosteric sea level at the tide gauge sites of the Norwegian sector and found that the recent increase in sea level has a dominant thermal origin. This suggests that inflow of warm North Atlantic waters may be responsible for the recent sea level changes observed along the Norwegian and Russian coasts. Comparison, over the altimetry era (since 1993), of altimetry-based and steric spatial trend patterns in sea level in the North Atlantic (>50°N) and Nordic Seas shows on the other hand that observed (altimetry-based) patterns essentially result from a combination of temperature and salinity effects, themselves driven by natural climate modes (AO and NAO).
Cazenave, A. A.; Henry, O.; Prandi, P.; Llovel, W.; Jevrejeva, S.
Radioactive contamination from dumped nuclear waste in the Kara Sea--results from the joint Russian-Norwegian expeditions in 1992-1994.
Russian-Norwegian expeditions to the Kara Sea and to dumping sites in the fjords of Novaya Zemlya have taken place annually since 1992. In the fjords, dumped objects were localised with sonar and ROV equipped with underwater camera. Enhanced levels of 137Cs, 60Co, 90Sr and 239,240Pu in sediments close to dumped containers in the Abrosimov and Stepovogo fjords demonstrated that leaching from dumped material has taken place. The contamination was inhomogeneously distributed and radioactive particles were identified in the upper 10 cm of the sediments. 137Cs was strongly associated with sediments, while 90Sr was more mobile. The contamination was less pronounced in the areas where objects presumed to be reactor compartments were located. The enhanced level of radionuclides observed in sediments close to the submarine in Stepovogo fjord in 1993 could, however, not be confirmed in 1994. Otherwise, traces of 60Co in sediments were observed in the close vicinity of all localised objects. Thus, the general level of radionuclides in waters, sediments and biota in the fjords is, somewhat higher or similar to that of the open Kara Sea, i.e. significantly lower than in other adjacent marine systems (e.g. Irish Sea, Baltic Sea, North Sea). The main sources contributing to radioactive contamination were global fallout from atmospheric nuclear weapon tests, river transport from Ob and Yenisey, marine transport of discharges from Sellafield, UK and fallout from Chernobyl. Thus, the radiological impact to man and the arctic environment of the observed leakages from dumped radioactive waste today, is considered to be low. Assuming all radionuclides are released from the waste, preliminary assessments indicate a collective dose to the world population of less than 50 man Sv. PMID:9241886
Salbu, B; Nikitin, A I; Strand, P; Christensen, G C; Chumichev, V B; Lind, B; Fjelldal, H; Bergan, T D; Rudjord, A L; Sickel, M; Valetova, N K; Føyn, L
NSDL National Science Digital Library
In Malaysia there is an island known for more sea turtles than virtually anywhere on Earth. In this video, Jonathan visits this amazing ecosystem to learn about the life cycle of sea turtles. He is surprised to discover an amazingly complex and competitive environment. Please see the accompanying study guide for educational objectives and discussion points.
Productions, Jonathan B.
Norwegian remote sensing experiment: Evaluation of the Nimbus 7 scanning multichannel microwave radiometer of sea ice research
An algorithm has been developed for estimating total and multiyear sea ice concentration from passive microwave and surface air temperature measurements. The algorithm was made for use with Nimbus 7 scanning multichannel microwave radiometer (SMMR) data. It is based on radiation physics and may thus easily be modified to suit other passive microwave instruments. A comparison between Nimbus 7 SMMR
E. Svendsen; K. Kloster; B. Farrelly; O. M. Johannessen; J. A. Johannessen; W. J. Campbell; P. Gloerse; D. Cavalieri; C. Mätzler
The genesis of sea level variability in the Barents Sea
NASA Astrophysics Data System (ADS)
The regional variability of sea level is an integral indicator of changing oceanographic conditions due to different processes of oceanic, atmospheric, and terrestrial origin. The present study explores the nature of sea level variability in the Barents Sea—a marginal shelf sea of the Arctic Ocean. A characteristic feature that distinguishes this sea from other Arctic shelf seas is that it is largely ice free throughout the year. This allows continuous monitoring of sea level by space-borne altimeters. In this work we combine satellite altimetry, ocean gravity measurements by GRACE satellites, available hydrography data, and a high-resolution ocean data synthesis product to estimate the steric and mass-related components of sea level in the Barents Sea. We present one of the first observational evidence of the local importance of the mass-related sea level changes. The observed 1-3 month phase lag between the annual cycles of sea level in the Barents Sea and in the Nordic seas (Norwegian, Iceland, Greenland seas) is explained by the annual mass-related changes. The analysis of the barotropic vorticity budget shows that the mass-related sea level variability in the central part of the Barents Sea is determined by the combined effect of wind stress, flow over the varying bottom topography, and dissipation, while the impact of vorticity fluxes is negligible. Overall, the steric sea level has smaller amplitudes and mainly varies on the seasonal time scale. The thermosteric sea level is the main contributor to the steric sea level along the pathways of the Atlantic inflow into the Barents Sea. The relative contribution of the halosteric sea level is dominant in the southeastern, eastern, and northern parts of the Barents Sea, modulated by the seasonal sea ice formation/melt as well as by continental runoff. The variability of the thermosteric sea level in the Barents Sea is mostly driven by variations in the net surface heat flux, whereas the contribution of heat advection becomes as important as the ocean-atmosphere heat exchange at interannual time scales.
Volkov, Denis L.; Landerer, Felix W.; Kirillov, Sergey A.
NSDL National Science Digital Library
This problem provides an opportunity to increase familiarity with negative and positive numbers on a number line. The vertical number line is presented as black markings every one meter all the way up a lighthouse and on the underwater support going down to the sea bed, with sea level being "0". In answering the nine questions, children begin to calculate with negative numbers in the context of the distances between the sea creatures. The Teachers' Notes page offers suggestions for implementation, discussion questions, ideas for extension and support, and a link to a related resource, Swimming Pool (cataloged separately).
A cold air outbreak over the Norwegian Sea observed with the Tiros-N Operational Vertical Sounder (TOVS) and the Special Sensor Microwave/Imager (SSM/I)
NASA Technical Reports Server (NTRS)
Until recently, the scarcity of meteorological observations over polar areas has limited studies of high latitude weather systems, but now data from polar orbiting satellites offer a new opportunity to observe and describe these systems. TOVS data were used successfully for delineating synoptic and subsynoptic systems since they provide the vertical temperature structure of the atmosphere: SSM/I observations have proved valuable for analyzing storms through water vapor and rain determinations. These positive results prompted us to analyze simultaneous TOVS and SSM/I observations obtained during a cold air outbreak over the Norwegian Sea. After a description of the instruments and the retrieval schemes, the mutually supporting information from these two independent instruments is discussed. Implications for the monitoring of polar lows are presented.
Claud, Chantal; Katsaros, Kristina B.; Petty, Grant W.; Chedin, Alain; Scott, Noelle A.
Extreme hydrogen, oxygen and carbon isotope anomalies in the pore waters and carbonates of the sediments and basalts from the Norwegian Sea: Methane and hydrogen from the mantle
D/H ratios in the pore waters of the sediments from the Norwegian Sea decrease as a function of depth to values as low as {minus}14{per thousand}. Oxygen isotope ratios in the pore waters and carbon and oxygen isotope ratios in carbonates both in the sediments and basalts are low. Extensive alteration of basalt has been given as the explanation for the low oxygen isotope ratios. Material balance calculations suggest that alteration of volcanic material and oxidation of organic matter cannot explain the hydrogen and carbon isotope anomalies. Arguments are presented suggesting that methane and hydrogen from the mantle are oxidized to carbon dioxide and water by sulfate and ferric iron in the basaltic crust to yield the low hydrogen and carbon isotope ratios.
Lawrence, J.R. (Univ. of Houston, University Park, TX (USA)); Taviani, M. (Instituto di Geologia Marina, del C.N.R., Bologna (Italy))
A cold air outbreak over the Norwegian Sea observed with the Tiros-N Operational Vertical Sounder (TOVS) and the Special Sensor Microwave/Imager (SSM/I)
NASA Technical Reports Server (NTRS)
Until recently, the scarcity of meteorological observations over polar areas has limited studies of high-latitude weather systems, but now data from polar orbiting satellites offer a new opportunity to observe and describe these systems. TOVS data have been used successfully for delineating synoptic and subsynoptic systems, since they provide the vertical temperature structure of the atmosphere; SSM/I observations have proved valuable for analyzing storms through water vapor and rain determinations. These positive results prompted simultaneous analysis of TOVS and SSM/I observations obtained during a cold air outbreak over the Norwegian Sea. After a description of the instruments and the retrieval schemes, the mutually supporting information from these two independent instruments is discussed. Implications for the monitoring of polar lows are presented.
Claud, Chantal; Katsaros, Kristina B.; Petty, Grant W.; Chedin, Alain; Scott, Noelle A.
Satellite observations of a polar low over the Norwegian Sea by Special Sensor Microwave Imager, Geosat, and TIROS-N Operational Vertical Sounder
NASA Technical Reports Server (NTRS)
Many polar lows are generated at the boundary between sea ice and the ocean, in regions of large temperature gradients, where in situ observations are rare or nonexistent. Since satellite observations are frequent in high-latitude regions, they can be used to detect polar lows and track their propagation and evolution. The Special Sensor Microwave/Imager (SSM/I) providing estimates of surface wind speed, integrated cloud liquid water content, water vapor content, and precipitation size ice-scattering signal over the ocean; the Geosat radar altimeter measuring surface wind speed and significant wave height; and the TIROS-N Operational Vertical Sounder (TOVS) allowing the determination of temperature and humidity profiles in the atmosphere have been used in synergy for a specific case which occurred in the Norwegian Sea on January, 23-24 1988. All three instruments show sharp atmospheric gradients associated with the propagation of this low across the ocean, which permit the detection of the polar low at a very early stage and tracking it during its development, propagation, and decay. The wind speed gradients are measured with good qualitative agreement between the altimeter and SSM/I. TOVS retrieved fields prior to the formation of the low confirm the presence of an upper level trough, while during the mature phase baroclinicity can be observed in the 1000-500 hPa geopotential thicknesses.
Claud, Chantal; Mognard, Nelly M.; Katsaros, Kristina B.; Chedin, Alain; Scott, Noelle A.
NSDL National Science Digital Library
This companion site to the new PBS series offers a collection of informative pieces and activities centered around the world's oceans. The site is divided into four principal sections, each of which features an article, brief sidebars, video clips, and in some cases, animations. The first, The Captain's Bridge, explores shipwrecks, stormy seas, and ocean rescues. The second, The Crow's Nest, dives into the power of waves. The Deep Sea section takes users to the nether regions of the ocean, while The Weather Factory touches on cyclones, ice and icebergs, and El Nino. Additional features at the site include Ask the Expert, Facts from the Sea, an annotated collection of related sites, and information about the series.
NASA Technical Reports Server (NTRS)
The Black Sea in eastern Russia is experiencing an ongoing phytoplankton bloom. This image, the most recent in a series that began in early may, shows the waters to be even more colorful than before. part of the increased brightness may be due to the presence of sun glint , especially in the center of the sea. However, more organisms appear to be present as well, their photosynthetic pigments reflecting different wavelengths of light.This Moderate Resolution Imaging Spectroradiometer (MODIS) image was captured on June 15, 2002.
NASA Technical Reports Server (NTRS)
During 2013, Arctic sea ice extent remained well below normal, but the September 2013 minimum extent was substantially higher than the record-breaking minimum in 2012. Nonetheless, the minimum was still much lower than normal and the long-term trend Arctic September extent is -13.7 per decade relative to the 1981-2010 average. The less extreme conditions this year compared to 2012 were due to cooler temperatures and wind patterns that favored retention of ice through the summer. Sea ice thickness and volume remained near record-low levels, though indications are of slightly thicker ice compared to the record low of 2012.
Perovich, D.; Gerland, S.; Hendricks, S.; Meier, Walter N.; Nicolaus, M.; Richter-Menge, J.; Tschudi, M.
NSDL National Science Digital Library
This is an excellent resource for information and teaching activities on marine life, designed primarily for elementary level. Teachers can sign up for a monthly e-newsletter (or access archived newsletters) filled with classroom activities, current information, and special links. Also features a searchable database of Sea World education materials and information on camps, marine science careers, and Shamu TV, an award-winning series broadcast around the country via satellite and cable.
Coccolithophore community composition and calcification rates in the Norwegian and Greenland seas as a function of carbonate chemistry and other environmental parameters.
NASA Astrophysics Data System (ADS)
The industrial revolution and the subsequent increase in fossil fuel combustion has led to a dramatic increase of carbon dioxide (CO2) released into the atmosphere. About a quarter of the anthropogenic CO2 released during the last few decades has been taken up by the ocean leading to a decrease in pH and CaCO3 saturation states (?). CaCO3 saturation states are lower in high latitude waters mainly due to the fact that cold water can hold more CO2 and that dissolved CO2 in most of the surface ocean is at near-equilibrium with the atmosphere. Current projections suggest that increasing uptake of CO2, combined with higher freshwater inputs from ice melt will lead to the entire water column of the arctic to become undersaturated with respect to aragonite by the end of this century. Although the effect of ocean acidification on marine calcifiers remains unclear, studies suggest that lower saturation states will have adverse consequences on several groups of calcifying organisms including some coccolithophore species. Coccolithophores play a major role in the ocean carbon cycle by contributing to both the biological and carbonate pumps. They are most prominent in high latitude waters although very little is known about what controls their distribution and abundance. The main goal of this study was to collect coccolithophore diversity, abundance and calcification rate data along transects of strong environmental and carbonate chemistry gradients. Here we present data collected in June 2009 along several transects between Norway, Greenland and Svalbard. Coccolithophore abundance, diversity and calcification rates were measured and compared with macronutrients, salinity, temperature, and carbonate chemistry parameters (i.e. TA, DIC, pH, pCO2 and ?). The strongest temperature gradients were observed along latitudinal transects with minimum SST values along the Greenland ice edge (T = 0-1 °C) and maximum values along the north Norwegian coast and the south-western coast of Spitsbergen Island (T = 5-8 °C). Surface salinity values were affected mainly by terrestrial freshwater inputs from Norway and Spitsbergen Island and ice melt along the Greenland ice edge. Saturation states of calcite and aragonite were highest along the eastern part of the study area (?cal = 3.4-3.9 ; ?arag = 2.1-2.5) and lowest along the Greenland ice edge (?cal = 2.9-3.3 ; ?arag = 1.8-2.1). Eleven coccolithophore species were identified during the cruise with Emiliania huxleyi and Calciopappus caudatus being the most abundant. Coccolithophore abundance, diversity and calcification rates decreased from southeast (Norwegian coast) northward (Spitsbergen) and westward (Greenland). Coccolithophores were nearly absent in the Greenland Sea with the exception of a small number of Coccolithus pelagicus. Multivariate analysis suggests that both temperature and carbonate chemistry are at least partly responsible for the distribution and abundance of coccolithophores in the Greenland and Norwegian Seas.
Loucaides, S.; Poulton, A.; Bellerby, R.; Tyrrell, T.
Summer at-sea distribution of seabirds and marine mammals in polar ecosystems: a comparison between the European Arctic seas and the Weddell Sea, Antarctica
The summer at-sea distribution of seabirds and marine mammals was quantitatively established both in Antarctica (Weddell Sea) and in the European Arctic: Greenland, Norwegian and Barents seas. Data can directly be compared, since the same transect counts were applied by the same team from the same icebreaking ship in both regions. The main conclusion is that densities of seabirds and
Claude R Joiris
NSDL National Science Digital Library
What reef animal comes in a rainbow of crazy colors, can throw out its innards to immobilize predators, then creep away and regrow a brand-new stomach? Itâs the sea cucumber, prized as a gastronomic delight by some cultures and beginning to yield some of its secrets to scientists. Follow host Ari Daniel Shapiro from a Chinatown market to the reefs of Fiji to learn more about this amazing creature. Also included is a Learn More section that provides background information on the scientists recorded in the podcast, lessons, images, and cool facts.
USGS sea otter researcher Tim Tinker drives the boat on an expedition to track and observe sea otters in Monterey Bay, California. USGS scientists study sea otters in efforts to help the threatened species continue to recover from near extinction....
ERIC Educational Resources Information Center
Presents information on sea mammals, including definitions and characteristics of cetaceans, pinnipeds, and sirenians. Contains descriptions of the teaching activities "Whale Music,""Draw A Whale to Scale,""Adopt a Sea Mammal," and "Sea Mammal Sleuths." (TW)
Naturescope, 1986
Sea otter researcher Michelle Staedler, of the Monterey Bay Aquarium, records sea otter behavior in her logbook as part of a study with the USGS and the University of California at Santa Cruz on sea otter behavior. ...
NASA Technical Reports Server (NTRS)
Sea ice covers vast areas of the polar oceans, with ice extent in the Northern Hemisphere ranging from approximately 7 x 10(exp 6) sq km in September to approximately 15 x 10(exp 6) sq km in March and ice extent in the Southern Hemisphere ranging from approximately 3 x 10(exp 6) sq km in February to approximately 18 x 10(exp 6) sq km in September. These ice covers have major impacts on the atmosphere, oceans, and ecosystems of the polar regions, and so as changes occur in them there are potential widespread consequences. Satellite data reveal considerable interannual variability in both polar sea ice covers, and many studies suggest possible connections between the ice and various oscillations within the climate system, such as the Arctic Oscillation, North Atlantic Oscillation, and Antarctic Oscillation, or Southern Annular Mode. Nonetheless, statistically significant long-term trends are also apparent, including overall trends of decreased ice coverage in the Arctic and increased ice coverage in the Antarctic from late 1978 through the end of 2003, with the Antarctic ice increases following marked decreases in the Antarctic ice during the 1970s. For a detailed picture of the seasonally varying ice cover at the start of the 21st century, this chapter includes ice concentration maps for each month of 2001 for both the Arctic and the Antarctic, as well as an overview of what the satellite record has revealed about the two polar ice covers from the 1970s through 2003.
Parkinson, Claire L.; Cavalieri, Donald J.
Estrogen receptor (ER) agonists and androgen receptor (AR) antagonists in effluents from Norwegian North Sea oil production platforms.
The in vitro estrogen receptor (ER) agonist and androgen receptor (AR) antagonist potencies of offshore produced water effluents collected from the Norwegian Sector were determined using recombinant yeast estrogen and androgen screens. Solid phase extraction (SPE) concentrates of the effluents showed E2 agonist activities similar to those previously reported for the United Kingdom (UK) Continental Shelf (<0.1-4 ng E2 L(-1)). No activity was detected in the filtered oil droplets suggesting that produced water ER activity is primarily associated with the dissolved phase. Targeted analysis for methyl- to nonyl-substituted alkylphenol isomers show the occurrence of known ER agonists in the analysed samples. For the first time, AR antagonists were detected in both the dissolved and oil associated phase at concentrations of between 20 and 8000 microg of flutamide equivalents L(-1). The identity of the AR antagonists is unknown, however this represents a significant input into the marine environment of unknown compounds that exert a known biological effect. It is recommended that further analysis using techniques such as bioassay-directed analysis is performed to identify the compounds/groups of compounds that are responsible in order to improve the assessment of the risk posed by produced water discharges to the marine environment. PMID:17258235
Tollefsen, Knut-Erik; Harman, Christopher; Smith, Andy; Thomas, Kevin V
Colorful Underwater Sea Creatures
ERIC Educational Resources Information Center
In this article, the author describes a project wherein students created colorful underwater sea creatures. This project began with a discussion about underwater sea creatures and how they live. The first step was making the multi-colored tissue paper that would become sea creatures and seaweed. Once students had the shapes of their sea creatures…
McCutcheon, Heather
National Technical Information Service (NTIS)
The Baltic Sea is one of the largest internal seas in Europe. The Baltic's significance in the history of our Motherland is great. The following questions are presented in the brochure: A political map of the Baltic Sea, NATO and the Baltic Sea; the strug...
L. P. Altman
Beaufort Sea: information update
The report is based on a multi-disciplinary meeting held March 6-7, 1985, as part of preparations for the Beaufort Sea Sale 97. The chapters are based on presentations given: The causeway effect: Modification of nearshore thermal regime resulting from causeways; Summertime sea ice intrusions in the Chukchi Sea; The deepwater limit of ice gouging on the Beaufort Sea shelf; Distribution, abundance, migration, harvest, and stock identity of Belukha Whales in the Beaufort Sea; Ringed seals in the Beaufort Sea; Beaufort Sea socioeconomics; The Baffin Island Oil Spill, (BIOS) Project.
Becker, P.R.
Atlantic Water flow through the Barents and Kara Seas
The pathway and transformation of water from the Norwegian Sea across the Barents Sea and through the St. Anna Trough are documented from hydrographic and current measurements of the 1990s. The transport through an array of moorings in the north-eastern Barents Sea was between 0.6Sv in summer and 2.6Sv in winter towards the Kara Sea and between zero and 0.3Sv
Ursula Schauer; Harald Loeng; Bert Rudels; Vladimir K. Ozhigin; Wolfgang Dieck
Geological Framework and Hydrocarbon Potential of Basins in the Northern Seas.
National Technical Information Service (NTIS)
This volume of the proceedings contains seven papers covering: the evolution of sedimentary basins in the Circum-Arctic; the Arctic north of Spitzbergen; structural and stratigraphic evolution of the Barents Sea; structural framework of the Norwegian Sea;...
NSDL National Science Digital Library
The Caribbean Conservation Corporation (CCC) was founded in 1959 by sea turtle champions such as ecologist Dr. Archie Carr, who served as the CCC's Scientific Director for nearly three decades. As the oldest sea turtle organization on the globe, the CCC "works to enact protective laws and establish refuges for the preservation of sea turtle habitats and coastal environments." The CCC created the Sea Turtle Survival League (STSL) in 1993 "as a public education and advocacy program to begin addressing the threats that face U.S. sea turtle populations." The CCC & STSL website contains information about a number of sea turtle programs and projects, tracking sea turtles, different sea turtle species, and ways to become a sea turtle conservationist. CCC also offers a public discussion board, a variety of downloadable publications (including activities for kids), and a collection of related links.
NSDL National Science Digital Library
Users can search for and view sea surface temperature imagery. They may choose from the latest image, or browse archived imagery that dates back approximately two weeks. Links to other sea surface temperature datasets are included.
NSDL National Science Digital Library
In this activity, learners will model how a sea turtle population changes over time, from eggs to adults, using puffed rice. Learners create a chart, calculate population fluctuation for each transitional stage of sea turtles' lives, and graph the population at each stage. Learners investigate different factors including migration and human fishing that affect the size of the sea turtle population. Relates to the linked video, DragonflyTV GPS: Sea Turtles.
Twin Cities Public Television, Inc.
Recent glacial events in the Norwegian North Sea - implications towards a better understanding of charging/leakage of oil fields and its impact oil exploration
NASA Astrophysics Data System (ADS)
Recent drilling and appraisal on the Southern Utsira High, Norwegian North Sea, has proved several large oil/gas discoveries, including the giant Johan Sverdrup, Edvard Grieg, Draupne, Ragnarrock and Apollo oil fields, making this a prolific petroleum area. The Southern Utsira High contains a variety of hydrocarbon density fluids found at several stratigraphic levels illustrating the compartmentalized nature of accumulations and charge history. The Southern Utsira High has been in a position to receive an oil/gas charge for a considerable period of time, with the basin towards the west most likely generating petroleum from early Eocene (50M Mabp) to its maximum present day burial depth. However, reservoir temperatures on the Southern Utsira High are just above the threshold for biodegradation (80°C). The Southern Utsira High oils are non-biodegraded suggesting that the majority of the oil charged relatively late - ca.3 million years ago to present day. The effects of the glaciation on the filling history of the Southern Utsira High are currently being assessed. It is clear that several erosional surfaces in the Pliocene can be identified, as well as glacial channels and moraine deposits, indicating that significant deposition and erosion occurred in the last five million years. Importantly, the effects of glacial rebound mean that the Southern Utsira High more than likely underwent tilting and possible leakage, not just once, but several times in the last 1 million years. The effects of tilting/leakage of geological areas on oil migration have been recognized by several authors. However, the detailed integration of geological mapping and geochemical evidence has not previously been published. The implications of a detailed assessment of tilting of a ''high' through time are; 1) opening up areas where oil migration is thought to be high risk or impossible; 2) identify possible paleo-oil columns aiding the de-risking of discovery appraisal strategies. The evidence of tilting/leakage of oil accumulations through time can be recognized in several oil fields on the Utsira High. The giant Johan Sverdrup discovery oil columns contain paleo-OWC, residual oil zones/paleo-oil columns, and oil shows considerably deeper than the current OWC or residual oil columns. Lundin has performed detailed mapping of the seabed and water column in the Alvheim/Utsira High areas in order to identify areas of gas leakage and its geological manifestations on the seabed and ultimately resulting in the collection of high quality samples. Results shows that gas leakage is prominent over the Alvheim and Utsira High areas and the implications of this to oil exploration will be discussed. In summary, Lundin's approach to oil migration is to better understand the fluid/gas movement throughout the whole basin through time. The talk will focus on the role of glaciations on the timing of charge from the South Viking Graben, fill-spill directions on the Southern Utsira High, the effects of late tilting/leakage on the charge/re-distribution of oil, and seabed / water column characterization and sampling. All placed in the context of oil exploration.
Stoddart, Daniel
Sea otter researchers Michelle Staedler, Monterey Bay Aquarium, and Tim Tinker, USGS, work together to locate sea otters in their study project. USGS scientists and their partners study sea otters in efforts to help the threatened species continue to recover from near extinction....
NSDL National Science Digital Library
In this lesson plan students will learn about special vehicles used in recent Black Sea research and the theory that the Black Sea during the Ice Age was an isolated freshwater lake surrounded by farmland that was eventually flooded. Students will describe the purpose of the research vehicles by writing newspaper articles pretending they have just returned from the Black Sea expedition.
ERIC Educational Resources Information Center
Hunting and gathering at sea may fast be approaching their productive limits. Aquaculture - farming at sea - linked to conservation represents the sea's promise. If the system works, it might prove to be the key to supplying large amounts of food and fresh water at no cost in nonrenewable energy resources. (BT)
NSDL National Science Digital Library
Headquartered in Woods Hole, Massachusetts, SEA offers a variety of science programs at sea for high school and college students. Site features information on the vessels, the crew, current voyages, admissions information, and a wealth of photographs from past expeditions. Also includes a section where you can track the progress of the SEA boats and hear daily, and archived, audio reports.
NSDL National Science Digital Library
The NOAA Sea Level Trends map illustrates U.S. regional and some international trends in sea level, with arrows representing the direction and magnitude of change. Students can investigate sea level changes around the U.S. and some worldwide using an interactive map interface with supporting data plots and tables.
Center For Operational Oceanographic Products And Services, Noaa
The paper develops an approach to the issues relating to sea level change that will assist the non-scientist and the applied scientist in making the most effective use of our existing and developing knowledge. The human perception of ''sea level'' and how that changes as societies change and develop are discussed. After some practical perspectives on the relationships between societies and sea levels are developed, an approach to developing the best available local prediction of sea level changes is outlined, and finally present knowledge and uncertainties about the future course of events that will influence ''sea level'' as defined in the practical sense is discussed.
Buddemeier, R.W.
NASA Technical Reports Server (NTRS)
The Aral Sea has shrunk to less than half its size since 1985. The Aral Sea receives little water (sometimes no water) from the two major rivers that empty into it-the Syr Darya and Amu Darya. Instead, the river water is diverted to support irrigation for the region's extensive cotton fields. Recently, water scarcity has increased due to a prolonged drought in Central Asia. As the Aral Sea recedes, its former sea bed is exposed. The Aral's sea bed is composed of fine sediments-including fertilizers and other agricultural chemicals-that are easily picked up by the region's strong winds, creating thick dust storms. The International Space Station crew observed and recorded a large dust storm blowing eastward from the Aral Sea in late June 2001. This image illustrates the strong coupling between human activities (water diversions and irrigation), and rapidly changing land, sea and atmospheric processes-the winds blow across the
Variability of Sea Surface Circulation in the Japan Sea
Composite sea surface dynamic heights (CSSDH) are calculated from both sea surface dynamic heights that are derived from altimetric data of ERS-2 and mean sea surface that is calculated by a numerical model. The CSSDH are consistent with sea surface temperature obtained by satellite and observed water temperature. Assuming the geostrophic balance, sea surface current velocities are calculated. It is
Akihiko Morimoto; Tetsuo Yanagi
Rigid topographic control of currents in the Nordic Seas
NASA Astrophysics Data System (ADS)
Neutrally buoyant floats, deployed across the northern slope of the Iceland-Faroe Ridge at 800m depth, reveal tight topographic control of their movement: a cluster of 22 floats drifts southeast to the Faroe-Shetland Channel where it bifurcates such that floats deployed over the upper slope turn south and eventually exit the Norwegian Sea through the Faroe Bank Channel, and floats over the deeper slope turn north in the Norwegian Sea. A subset of the latter group moves quickly north along the western slope of the Vøring Plateau and divides with most of the floats turning east into the Lofoten Basin and the remainder circulating cyclonically around the Norwegian Basin. This study establishes that i) the Faroe Bank Channel overflow waters must come from along the slope north of the Faroes, not the interior of the Norwegian Sea, and ii) exchange of intermediate waters between basins takes place along topographically controlled routes.
Søiland, H.; Prater, M. D.; Rossby, T.
Sea Ice Variability in the Bering Sea
NASA Astrophysics Data System (ADS)
The Bering Sea consists of a shallow continental shelf in the northeast and a deep basin in the southwest. Sea ice in the Bering Sea concentrating in the shelf region exhibits large seasonal and interannual variations, which significantly impact the local marine ecosystem. Understanding of the physical mechanisms governing this sea-ice variability, however, remains incomplete. To better understand regional sea-ice variability we use a fine resolution (1/10-degree) global ocean and sea-ice model and available observations. The simulation consists of the Los Alamos National Laboratory Parallel Ocean Program (POP) and CICE models, and was run with Coordinated Ocean-ice Reference Experiment (CORE2) interannually varying atmospheric forcing for 1970-1989. Here we analyze 1980-1989; the first 10 years are treated as the spin-up period. We examine the partitioning of the ice volume tendencies into thermodynamic and dynamic components, as well as corresponding surface atmospheric and oceanic variables, in order to understand the relationship between sea ice variability and varying atmospheric and oceanic conditions. Focusing on the seasonal cycle first, we find that sea ice is mainly formed in the northern Bering Sea with the maximum ice growth rate occurring along the coast. Winds cause sea ice to drift southwestward from the north to the western ice edge. Along the ice edge, ice is melted by warm waters carried by the Bering Slope Current, especially in the west in winter; while in fall and spring, basal melting of sea ice spreads into the interior of ice pack. The ice growth rate is larger in winter than in fall and spring. Ice transport from the north to the southwest becomes weaker in fall and spring than in winter. The Bering Sea is ice free in summer. Surface melting is insignificant in all seasons. The interannual variability of sea ice in the Bering Sea can be largely explained by thermodynamics on the large scale. The dynamic ice transport, however, is often important locally, especially around the ice margins with ocean and land. Local dynamic and thermodynamic ice volume changes usually have opposite signs with similar magnitudes, implying a negative feedback between them. Through the surface heat flux budget, we find that sensible heat flux dominates the surface heat exchange with the atmosphere, which controls the ice growth in the north. Ocean-ice heat flux largely determines the basal melting along the ice edge in the south. Through the force balance analysis, we find that the ice motion is in steady state on the monthly timescale. Ice velocity correlates well with the wind stress, which is nearly balanced by the opposite ocean stress. Internal ice stress is not substantial except near the land boundaries in the north.
Li, L.; Miller, A. J.; McClean, J.; Eisenman, I.; Hendershott, M.
NSDL National Science Digital Library
SeaWIFS (Sea-viewing Wide Field-of-view Sensor), a NASA project using satellites to collect ocean color data to quantify phytoplankton abundance. Provides background information on SeaWIFS project, technology and data. Teacher Resource section has: online presentation on how and why scientists study ocean color; Living Ocean Teacher's Guide with brief information on ocean color, carbon cycle and greenhouse gas effect; and, links to other websites with ocean color activities.
NSDL National Science Digital Library
The National Sea Grant Library (NSGL) is the digital library and official archive for NOAA Sea Grant documents. It is the only comprehensive collection of Sea Grant Âfunded documents from over 30 programs and projects across the country. This collection encompasses a wide variety of subjects, including oceanography, marine education, aquaculture, fisheries, aquatic nuisance species, coastal hazards, seafood safety, limnology, coastal zone management, marine recreation, and law.
NSDL National Science Digital Library
This packet includes background information, quick facts, links to additional sea turtle resources, and a classroom modeling activity that demonstrates population estimation, life history, and hatching success rates.
Forcing of oceanic heat anomalies by air-sea interactions in the Nordic Seas area
Hydrographic data and atmospheric reanalysis from 1982 to 2005 are used to show a strong link of the Atlantic water temperature (AWT) anomalies observed in the transition zone between the Norwegian Atlantic current and the West Spitsbergen current in summer to the surface heat flux (SHF) anomalies observed over the Barents Sea open water in the preceding late winter. A
P. Schlichtholz; M.-N. Houssais
Recent drilling in the Red Sea has shown that much of the basin is underlain by evaporites of a similar age to that of evaporites found in the Mediterranean Sea. These evaporites and their structural positions indicate that other brine areas are present - and, indeed, several others have been discovered.
Ross, D. A.; Whitmarsh, R. B.; Ali, S. A.; Boudreaux, J. E.; Coleman, R.; Fleisher, R. L.; Girdler, R.; Manheim, F.; Matter, A.; Nigrini, C.; Stoffers, P.; Supko, P. R.
Sea travel mandates changes in the control of the body. The process by which we adapt bodily control to life at sea is known as getting one's sea legs. We conducted the first experimental study of bodily control as maritime novices adapted to motion of a ship at sea. We evaluated postural activity (stance width, stance angle, and the kinematics of body sway) before and during a sea voyage. In addition, we evaluated the role of the visible horizon in the control of body sway. Finally, we related data on postural activity to two subjective experiences that are associated with sea travel; seasickness, and mal de debarquement. Our results revealed rapid changes in postural activity among novices at sea. Before the beginning of the voyage, the temporal dynamics of body sway differed among participants as a function of their (subsequent) severity of seasickness. Body sway measured at sea differed among participants as a function of their (subsequent) experience of mal de debarquement. We discuss implications of these results for general theories of the perception and control of bodily orientation, for the etiology of motion sickness, and for general phenomena of perceptual-motor adaptation and learning.
Stoffregen, Thomas A.; Chen, Fu-Chen; Varlet, Manuel; Alcantara, Cristina; Bardy, Benoit G.
Kara Sea radioactivity assessment
Investigations following five international expeditions to the Kara Sea have shown that no radiologically significant contamination has occurred outside of the dumping sites in Novaya Zemlya bays. Increased levels of radionuclides in sediment have only been observed in Abrosimov and Stepovoy Bays very close to dumped containers. Evaluations of radionuclide inventories in water and sediment of the open Kara Sea
Iolanda Osvath; Pavel P Povinec; Murdoch S Baxter
NSDL National Science Digital Library
Classroom activity introduces the biology of sea turtles, population status, human impacts. Focuses on Kemp's ridley (Lepidochelys kempii), smallest and more endangered of sea turtle species. This teacher's guide provides NOAA tracking data and instructions for students to follow the migration routes of six turtles in the Gulf of Mexico. Links to related activities using satellite data.
USGS wildlife biologist Alisha Kage holds out a VHF receiver, hoping to hear the tell-tale beep that helps her locate sea otters that are part of study to monitor and learn more about the species. USGS scientists study sea otters in efforts to help the threatened species continue to recover from nea...
National Technical Information Service (NTIS)
The paper develops an approach to the issues relating to sea level change that will assist the non-scientist and the applied scientist in making the most effective use of our existing and developing knowledge. The human perception of ''sea level'' and how...
R. W. Buddemeier
ERIC Educational Resources Information Center
Several investigations can be undertaken with live sea anemones. A sea anemone's feeding response, fighting power, color, and symbiotic relationships to other invertebrates (such as a marine hermit crab) can be investigated in the high school classroom. Background information and laboratory procedures are provided. (Author/JN)
Hunt, John D.
USGS wildlife biologist Alisha Kage looks through a telescope to help her locate and identify tagged sea otters, then records the otter's location for a study aimed at learning more about the species. USGS scientists study sea otters in efforts to help the threatened species continue to recover from...
NSDL National Science Digital Library
Video and animations of sea level from NASA's Climate website. Since 1992, NASA and CNES have studied sea surface topography as a proxy for ocean temperatures. NASA Missions TOPEX/Poseidon, Jason 1 and Jason 2 have been useful in predicting major climate, weather, and geologic events including El Nino, La Nina, Hurricane Katrina, and the Indian Ocean Tsunami.
Jackson, Randall; Nasa, For
NASA Technical Reports Server (NTRS)
At bottom center of this true-color Moderate Resolution Imaging Spectroradiometer (MODIS) image from April 13, 2001, the White Sea in western Russia is becoming free of ice in its southern extent. Meanwhile, the blue-green waters along the coast of the peninsula jutting out into the Barents Sea to the northeast could be due to a phytoplankton bloom.
NSDL National Science Digital Library
In this investigation learners research the effects of melting sea ice in the Bering Sea Ecosystem. They create research proposals to earn a place on the scientific research vessel Healy and present their findings and proposals to a Research Board committee.
Curriculum, Alaska S.; Grant, Alaska S.
Water column monitoring near oil installations in the North Sea 2001–2004
Fisheries have been vital to coastal communities around the North Sea for centuries, but this semi-enclosed sea also receives large amounts of waste. It is therefore important to monitor and control inputs of contaminants into the North Sea. Inputs of effluents from offshore oil and gas production platforms (produced water) in the Norwegian sector have been monitored through an integrated
Ketil Hylland; Knut-Erik Tollefsen; Anders Ruus; Grete Jonsson; Rolf C. Sundt; Steinar Sanni; Toril Inga Røe Utvik; Ståle Johnsen; Ingunn Nilssen; Laurence Pinturier; Lennart Balk; Janina Baršien?; Ionan Marigòmez; Stephen W. Feist; Jan Fredrik Børseth
Variations in Ionic Ratios between Reference Sea Water and Marine Aerosols
Atmospheric particles were collected over the open sea (western Mediterranean, North Atlantic, and Norwegian Sea) by air filtration and cascade impactor sampling. The observed K\\/Na concentration ratios exhibited marked variation and were greater than the reference ratio in bulk sea water. These concentration ratios can be related to the existence of a chemical fractionation affecting the marine aerosols produced by
Roger Chesselet; Jacques Morelli; Patrick Buat-Menard
Laptev sea system discussed at Russian-German Workshop
NASA Astrophysics Data System (ADS)
The Laptev Sea covers the central part of the vast Arctic shelf seas off northern Eurasia. It receives large volumes of fresh water from the Lena River and other big rivers that drain the central part of Siberia; peak runoff occurs in the early summer. Being tucked away between two groups of islands—Severnaya Zemlya in the west and the New Siberian Islands in the east—and connected to the Kara Sea in the west and the East Siberian Sea in the east only through relatively narrow straits, the Laptev Sea is an important area for sea-ice formation in the Arctic Ocean [Rigor and Colony, 1997; Kassens et al., 1999].Through sea ice formation, the Laptev Sea influences the ice cover of the central Arctic Ocean and its Transpolar Drift, which exports sea ice into the western Norwegian-Greenland Sea. The Laptev Sea is also the central segment of the Northern Sea Route. For this reason, commercial interests wish to gain valuable knowledge about the extremes of its modern environment, past variability and predictability on time scales of months and years. Both in the Laptev Sea and on the adjacent land regions, large tracts of subterraneous and submarine permafrost have been observed as a consequence of the extreme paleoclimate of the latest geological past.
Thiede, J.; Kassens, H.; Timokhov, L.
Published values for the long-term, global mean sea level rise determined from tide gauge records exhibit considerable scatter, from about 1 mm to 3 mm/yr. This disparity is not attributable to instrument error; long-term trends computed at adjacent sites often agree to within a few tenths of a millimeter per year. Instead, the differing estimates of global sea level rise appear to be in large part due to authors' using data from gauges located at convergent tectonic plate boundaries, where changes of land elevation give fictitious sea level trends. In addition, virtually all gauges undergo subsidence or uplift due to postglacial rebound (PGR) from the last deglaciation at a rate comparable to or greater than the secular rise of sea level. Modeling PGR by the ICE-3G model of Tushingham and Peltier (1991) and avoiding tide gauge records in areas of converging tectonic plates produces a highly consistent set of long sea level records. The value for mean sea level rise obtained from a global set of 21 such stations in nine oceanic regions with an average record length of 76 years during the period 1880-1980 is 1.8 mm/yr {plus minus} 0.1. This result provides confidence that carefully selected long tide gauge records measure the same underlying trend of sea level and that many old tide gauge records are of very high quality.
Douglas, B.C. (NOAA, Rockville, MD (USA))
Distribution of coccolithophores in marginal seas along the western Pacific Ocean and in the Red Sea
The distribution of coccolithophores was studied in the neritic environment along the western margin of the Pacific Ocean: the Inland Sea of Seto, Yellow Sea, East China Sea, South China Sea, Java Sea, Timor Sea, Arafura Sea and Gulf of Carpentaria. The coccolithophore community in the Red Sea was also studied for comparison with the Pacific marginal seas. With minor
H. Okada; S. Honjo
Tobacco smoking, an independent determinant for unhealthy diet? A cross-sectional study of Norwegian workers on platforms in the North Sea
The objective of the study was to examine whether male tobacco smokers had a more unhealthy diet than non-smokers. Data on smoking and other variables were collected by questionnaire interviews and food intake by one 24 h recall. The setting was 2 oil platforms. The participants were 310 healthy men working on 2 platforms in the Norwegian sector of the
NSDL National Science Digital Library
In this video-based activity, students learn that sea level is an average measurement of the height of the ocean, and sea level changes with the seasons and over time. El Niño and La Ninña events are compared, demonstrating that sea height is a function of temperature.Summary background information, data and images supporting the activity are available on the Earth Update data site. To complete the activity, students will need to access the Space Update multimedia collection, which is available for download and purchase for use in the classroom.
NSDL National Science Digital Library
In this activity students will observe that the sea level changes and will hypothesize what causes this change. They will then check their hypothesis with a data set. Many students are surprised to learn that sea level is not the same everywhere on earth and that it changes with the seasons. The main cause of this change is the temperature change in the ocean - warmer waters are higher than colder waters. Students will discover this information as they complete the activity and then see if the temperature effect holds true on another data set showing temperature and sea height changes caused by the El Nino/Southern Oscillation (ENSO).
Near drowning in the Dead Sea is associated with both respiratory manifestations and severe electrolyte abnormalities. It is often difficult to distinguish between the contributions of sea water aspiration or ingestion to clinical manifestations. We present a unique case of accidental ingestion of a large amount of Dead Sea water through a gastrostomy tube in which a patient with familial dysautonomia presented with severe electrolyte disturbances. Forced diuresis with large amounts of intravenous fluids resulted in clinical and biochemical improvement. Full recovery was achieved after 2 days of treatment. PMID:22863826
Levy-Khademi, Floris; Brooks, Rebecca; Maayan, Channa; Tenenbaum, Ariel; Wexler, Isaiah D
NSDL National Science Digital Library
In this activity, learners explore how the area of Arctic sea ice has changed over recent years. First, learners graph the area of Arctic sea ice over time from 1979 to 2007. Then, learners use this information to extrapolate what the area will be in 2018 and graph their predictions. In part two of the activity, learners make a flip book to simulate the sea changes they just graphed. This resource includes background information related to the Northwest Passage and questions for learners to answer after completing this activity.
Meier, Beverly L.
NASA Technical Reports Server (NTRS)
Published values for the long-term, global mean sea level rise determined from tide gauge records range from about one to three mm per year. The scatter of the estimates appears to arise largely from the use of data from gauges located at convergent tectonic plate boundaries where changes of land elevation give fictitious sea level trends, and the effects of large interdecadal and longer sea level variations on short (less than 50+ years) or sappy records. In addition, virtually all gauges undergo subsidence or uplift due to isostatic rebound from the last deglaciation at a rate comparable to or greater than the secular rise of sea level. Modeling rebound by the ICE-3G model of Tushingham and Peltier (1990) and avoiding tide gauge records in areas of converging tectonic plates produces a highly consistent set of long sea level records. A global set of 21 such stations in nine oceanic regions with an average record length of 76 years during the period 1880-1980 yields the global sea level rise value 1.8 mm/year +/- 0.1. Greenhouse warming scenarios commonly forecast an additional acceleration of global sea level in the next 5 or 6+ decades in the range 0.1-0.2 mm/yr2. Because of the large power at low frequencies in the sea level spectrum, very long tide gauge records (75 years minimum) have been examined for past apparent sea level acceleration. For the 80-year period 1905-1985, 23 essentially complete tide gauge records in 10 geographic groups are available for analysis. These yielded the apparent global acceleration -0.011 (+/- 0.012) mm/yr2. A larger, less uniform set of 37 records in the same 10 groups with 92 years average length covering the 141 years from 1850-1991 gave 0.001 (+/- 0.008) mm/yr2. Thus there is no evidence for an apparent acceleration in the past 100+ years that is significant either statistically, or in comparison to values associated with global warming. Unfortunately, the large interdecadal fluctuations of sea level severely affect estimates of global sea level acceleration for time spans of less than about 50 years. This means that tide gauges alone cannot serve as a reliable leading indicator of climate change in less than many decades. This time required can be significantly reduced if the interdecadal fluctuations of sea level can be understood in terms of their forcing mechanisms, and then removed from the tide gauge records.
Douglas, Bruce C.
The north Sulu Sea productivity
NASA Astrophysics Data System (ADS)
The Sulu Sea is a part of the western North Pacific. It is a closed sea for its deep water and a semi-closed sea for its upper layer. The Sulu Sea exchanges mainly surface waters with the South China Sea and the Celebes Sea. The Sulu Sea is more productive than the adjacent South China Sea (Jones, 2002). On the basis of MERIS satellite observations from 2002 to 2008, we focus on the high-chlorophyll area as an indicator of the abundance of primary productivity in the Sulu Sea. Strong chlorophyll concentration in the north Sulu Sea close to the Mindoro Strait mainly occurs from December to March and low chlorophyll concentration happens in April to November. The adjacent South China Sea on the other side of Mindoro Strait has shown persistent signs of low chlorophyll concentration. Based on 1/8° Global Navy Coastal Ocean Model, the intrusion of the South China Sea waters through the Mindoro Strait to the Sulu Sea from April to November is the main reason for the low chlorophyll concentration observed in the north Sulu Sea. During April to November, the South China Sea waters flow through the Mindoro Strait and stay on the surface of the north Sulu Sea because of their low density. The north Sulu Sea waters mix with fresher waters coming from the South China Sea without new nutrients supply. When the inflow from South China Sea to Sulu Sea ceases in December to March, the upwelling due to the summer monsoon wind becomes an important mechanism supplying deep nutrients to the surface water which lead to high chlorophyll concentration. Jones, I.S.F., 2002. Primary production in the Sulu Sea. Proceedings of the Indian Academy of Sciences-Earth and Planetary Sciences 111, 209-213.
Xiao, Z.
The rotifer fauna of arctic sea ice from the Barents Sea, Laptev Sea [2pt] and Greenland Sea
Samples from arctic sea ice were studied for their rotifer fauna. Ice core samples were collected in the northern Barents Sea and the Laptev Sea from August to October 1993 and in the Greenland Sea from July to August 1994. Eight rotifer taxa, Encentrum graingeri, Proales reinhardti, Synchaeta bacillifera, S. cecilia, S. glacialis, S. hyperborea, S. tamara and S. sp.,
Christine Friedrich; Willem H. De Smet
It is shown how the drag of the sea surface can be computed from the wind speed and the sea state. The approach, applicable both for fully developed and for developing seas, is based on conservation of momentum in the boundary layer above the sea, which allows one to relate the drag to the properties of the momentum exchange between
V. K. Makin; V. N. Kudryavtsev; C. Mastenbroek
National Technical Information Service (NTIS)
HR Wallingford and Southampton University are supporting the USACE in the development of an Engineering Technical Letter (ETL), in relation to extreme sea levels and climate impact adaptation. Lead personnel responsible for the USACE are Dr Kathleen White...
NASA Technical Reports Server (NTRS)
A consortium of researchers from Jet Propulsion Laboratory and three other organizations used charged coupled devices (CCDs) and other imaging enhancement technology to decipher previously unreadable portions of the Dead Sea Scrolls. The technique has potentially important implications for archeology.
NSDL National Science Digital Library
Sea urchins live in low tide regions and eat seaweed. Urchins have no arms but have five rows of tube feet for movement. They are found in holes and use their spines for protection and to burrow into the rocks.
Katie Hale (California State University, Fullerton;Student, Biological Sciences)
ERIC Educational Resources Information Center
Describes a three-week inservice teacher education program that involves two sessions of preparatory classes ashore in nautical science and oceanography, and concludes with a nine-day sea voyage. (ASK)
Phillips, Mary Nied
ERIC Educational Resources Information Center
Outlines the experiences of a teacher in the National Oceanic and Atmospheric Administration's (NOAA) Teacher At Sea Program in which teachers are placed on NOAA vessels to work with professional scientists doing critical, real world research. (DDR)
Beighley, Karl
NASA Astrophysics Data System (ADS)
Polar sea ice is one of the largest ecosystems on Earth. The liquid brine fraction of the ice matrix is home to a diverse array of organisms, ranging from tiny archaea to larger fish and invertebrates. These organisms can tolerate high brine salinity and low temperature but do best when conditions are milder. Thriving ice algal communities, generally dominated by diatoms, live at the ice/water interface and in recently flooded surface and interior layers, especially during spring, when temperatures begin to rise. Although protists dominate the sea ice biomass, heterotrophic bacteria are also abundant. The sea ice ecosystem provides food for a host of animals, with crustaceans being the most conspicuous. Uneaten organic matter from the ice sinks through the water column and feeds benthic ecosystems. As sea ice extent declines, ice algae likely contribute a shrinking fraction of the total amount of organic matter produced in polar waters.
Arrigo, Kevin R.
Polar sea ice is one of the largest ecosystems on Earth. The liquid brine fraction of the ice matrix is home to a diverse array of organisms, ranging from tiny archaea to larger fish and invertebrates. These organisms can tolerate high brine salinity and low temperature but do best when conditions are milder. Thriving ice algal communities, generally dominated by diatoms, live at the ice/water interface and in recently flooded surface and interior layers, especially during spring, when temperatures begin to rise. Although protists dominate the sea ice biomass, heterotrophic bacteria are also abundant. The sea ice ecosystem provides food for a host of animals, with crustaceans being the most conspicuous. Uneaten organic matter from the ice sinks through the water column and feeds benthic ecosystems. As sea ice extent declines, ice algae likely contribute a shrinking fraction of the total amount of organic matter produced in polar waters. PMID:24015900
Arrigo, Kevin R
For a very large part of human history, the Dead Sea has been considered a prime example of an environment completely devoid\\u000a of life, a condition which during the Greco-Roman period was ascribed to natural causes—the bitterness of the water and the\\u000a hydrogen sulphide stench associated with the area. In the Middle Ages, however, attitudes towards the Dead Sea changed
Arie Nissenbaum
NSDL National Science Digital Library
Detailed information on the biology, natural history, factors influencing the population, and protection measures of green sea turtles (Chelonia mydas). Included are three in-class activities and one field activity all designed to raise awareness of the green sea turtle and what humans are doing to affect the population. The site is geared towards the Hawaiian sub-species, however, most of the facts and activities are applicable elsewhere.
NSDL National Science Digital Library
This comprehensive site is an introduction to sea ice: what it is, how it forms, how it is studied, how it affected historical expedition in the polar regions, and what role it plays in the global climate. The site contains a glossary of sea ice terms and references to additional information, which all serve as an excellent introduction. Data are also available from various collection methods for student interpretation.
NSDL National Science Digital Library
This comprehensive site is an introduction to sea ice: what it is, how it forms, how it is studied, how it affected historical expedition in the polar regions, and what role it plays in the global climate. The site contains a glossary of sea ice terms and references to additional information, which all serve as an excellent introduction. Data are also available from various collection methods for student interpretation.
NSDL National Science Digital Library
This web page from the National Snow and Ice Data Center contains two related visualizations. The first visualization gives an estimate of the percent contribution to sea level change since the 1990s from three contributors - small glaciers and ice caps, the Greenland Ice Sheet and the Antarctic Ice Sheet. The second visualization shows the cumulative contribution to sea level from small glaciers and ice caps plotted with the annual global surface air temperature anomaly.
Meier, M. F.; Dyurgerov, Mark; Center, National S.
NSDL National Science Digital Library
This website presents ocean topography as measured by sea surface heights taken from space by NASA and CNES. Ocean heat circulation impacts weather and causes events such as Large El Nino, Hurricane Katrina, Indian Ocean Tsunami and La Nina. These events and the latest view of sea surface height are depicted with this 3D interactive viewer. Objectives of NASA missions TOPEX/Poseiden, Jason 1, and Jason 2/OSTM are charted. Closed Captioning is available.
Nordic Seas dissolved oxygen data in CARINA
NASA Astrophysics Data System (ADS)
Water column data of carbon and carbon relevant hydrographic and hydrochemical parameters from 188 previously non-publicly available cruises in the Arctic, Atlantic, and Southern Oceans have been retrieved and merged into a new database: CARINA (CARbon IN the Atlantic). This paper is one of a series of papers related to the CARINA project and presents an account of the quality control of the oxygen data from the Nordic Seas (the Greenland, Norwegian, and Iceland Seas) in CARINA. Out of 35 cruises from the Nordic Seas included in CARINA, 32 had oxygen data, spanning the period from 1982 to 2006. These data have been subject to rigorous quality control in order to ensure highest possible quality and consistency. Oxygen data from four cruises have been adjusted in the final CARINA data product.
Falck, E.; Olsen, A.
NASA Technical Reports Server (NTRS)
Editor's Note: The caption below, published on May 10, 2001, is incorrect. According to Masha Vorontsova, director of the International Fund for Animal Welfare in Moscow, the situation with the seal pups in the White Sea is normal. There is no disaster and there never was. For more details, refer to the article entitled 'No Danger' on the New Scientist home page. The Earth Observatory regrets the earlier errant report. Original Caption According to the Russian Polar Research Institute for Fisheries and Oceanography, between 250,000 and 300,000 Greenland seal pups face death by starvation over the next two months due to a cruel trick by mother nature. The seals, most of them less than two months old, are trapped on ice sheets that remain locked in the White Sea, located near Archangel in Northern Russia. Typically, during the spring thaw the ice sheets break up and flow with the currents northward into the Barents Sea, the seals' spring feeding grounds. The seal pups hitch a ride on the ice floes, living on their own individual stores of fat until they arrive in the Barents Sea. Their mothers departed for the Barents Sea weeks ago. In a normal year, the seal pups' trip from the White Sea out to the Barents takes about six weeks and the seals have adapted to rely upon this mechanism of mother nature. During their yearly migration, the mother seals usually stay with their pups and feed them until their pelts turn from white to grey--a sign that the pups are mature enough to swim and feed themselves. Unfortunately, this year unusually strong northerly winds created a bottleneck of ice near the mouth of the white sea, thus blocking the flow of ice and trapping the pups. These true-color images of the White Sea were acquired by the Moderate-resolution Imaging Spectroradiometer (MODIS), flying aboard NASA's Terra spacecraft. This image, taken May 2, 2000 that there is usually much less ice in the White Sea this time of year as most of it is typically en route to the Barents Sea.
On large outflows of Arctic sea ice into the Barents Sea
NASA Technical Reports Server (NTRS)
Winter outflows of Arctic sea ice into the Barents Sea are estimated using a 10-year record of satellite ice motion and thickness. The mean winter volume export through the Svalbard/Franz Josef Land passage is 40 km3, and ranges from -280 km3 to 340 km3. A large outflow in 2003 is preconditioned by an unusually high concentration of thick perennial ice over the Nansen Basin at the end of the 2002 summer. With a deep atmospheric low situated over the eastern Barents Sea in winter, the result is an increased export of Arctic ice. The Oct-Mar ice area flux, at 110 x 10 to the third power km3, is not only unusual in magnitude but also remarkable in that >70% of the area is multiyear ice; the ice volume flux at340 km3 is almost one-fifth of the ice flux through the Fram Strait. Another large outflow of Arctic sea ice through this passage, comparable to that in 2003, is found in 1996. This southward flux of sea ice represents one of two major sources of freshwater in the Barents Sea; the other is the eastward flux of water via the Norwegian Coastal Current. The possible consequences of variable freshwater input on the Barents Sea hydrography and its impact on transformation of Atlantic Water en route to the Arctic Ocean are examined with a 25-year coupled ice-ocean model.
Kwok, Ron; Maslowski, Wieslaw; Laxon, Seymour W.
Influence of the White Sea on tides in adjacent marginal seas of the North European Basin
NASA Astrophysics Data System (ADS)
An investigation into the interaction of surface M 2 tides in the system of marginal seas of the North European Basin is carried out using the three-dimensional finite-element hydrostatic model QUODDY-4. Three numerical experiments are performed for this purpose. In the first (control), the model equations are solved in the system of the Norwegian, Greenland, Barents, and White seas; thereby the interaction of the tides in these seas is explicitly taken into account. In the second experiment, the White Sea is excluded from consideration and the no-flux condition is posed at the entrance to the sea. The third experiment uses an approach in which the observed tidal elevations that determine the existence of a finite horizontal transport of barotropic energy to the White Sea are specified at the open boundary of the White Sea. It is shown that changes in tidal dynamics represented by changes in the amplitudes and phases of tidal elevations and in the barotropic tidal velocity ellipse parameters are within the model noise in experiments 2 and 3 when compared with the control experiment. On the contrary, changes in energy characteristics (the horizontal wave transport, density, and dissipation rate of barotropic tidal energy) are equal to or greater (in order of magnitude) than the energy characteristics themselves.
Kagan, B. A.; Sofina, E. V.; Rashidi, E. H. A.
NASA Technical Reports Server (NTRS)The Dead Sea is the lowest point on Earth at 418 meters below sea level, and also one of the saltiest bodies of water on Earth with a salinity of about 300 parts-per-thousand (nine times greater than ocean salinity). It is located on the border between Jordan and Israel, and is fed by the Jordan River. The Dead Sea is located in the Dead Sea Rift, formed as a result of the Arabian tectonic plate moving northward away from the African Plate. The mineral content of the Dead Sea is significantly different from that of ocean water, consisting of approximately 53% magnesium chloride, 37% potassium chloride and 8% sodium chloride. In the early part of the 20th century, the Dead Sea began to attract interest from chemists who deduced that the Sea was a natural deposit of potash and bromine. From the Dead Sea brine, Israel and Jordan produce 3.8 million tons potash, 200,000 tons elemental bromine, 45,000 tons caustic soda, 25, 000 tons magnesium metal, and sodium chloride. Both countries use extensive salt evaporation pans that have essentially diked the entire southern end of the Dead Sea. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet. ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance. The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate. Size: 18.5 by 48.1 kilometers (11.5 by 29.8 miles) Location: 31.4 degrees North latitude, 35.4 degrees East longitude Orientation: North at top Image Data: ASTER bands 3, 2, and 1 Original Data Resolution: 15 meters (49.2 feet) Dates Acquired: May 3, 2005
Bioprospecting / Deep Sea Research
NSDL National Science Digital Library
The first portion of the radio broadcast discusses the relatively new field of bioprospecting, the exploration of the sea floor for novel compounds and processes that may have industrial or medical applications. Bioprospectors are trying to collect samples of deep-sea organisms which may yield new pharmaceutical compounds, as in the case of Conus magnus, a sea snail whose venom has yielded a painkiller 1000 times more potent than morphine. There is also discussion of who owns these resources and what can be done to protect them. This segment is 12 minutes in length. The second segment of the broadcast traces the history of undersea exploration, including methods of measuring ocean depth, the bathysphere used by William Beebe and Otis Barton, the modern Alvin submersible, and remotely operated vehicles. There is also discussion of the motives and inspiration for ocean exploration; the deep sea knowledge of whalers; and comparisons of deep sea research with space exploration. This segment is 34 minutes and 40 seconds in length.
Fabrication of a NAVMAP, A Deep-Sea Mapping System. Part 2.
National Technical Information Service (NTIS)
Through summer 1994, SEAMAP has been successfully used in eight survey operations by NAVOCEANO totalling approximately 200 days of operation in the eastern North Atlantic Ocean and Norwegian Sea. SEAMAP system development included design and fabrication o...
A. Shor
NSDL National Science Digital Library
SeaWeb is a nonprofit organization aimed at raising awareness of the ocean and marine life that play "a critical role in our everyday life and in the future of our planet." SeaWeb employs a team of professionals from biology, exploration, and various communication disciplines. The current campaigns include an effort to protect the declining Caspian Sea Sturgeon ("the source of most of the world's caviar"), an attempt to reduce overfishing of swordfish, and a report about the changes occurring in the world's oceans. This Web site is a robust source of information about many threats that are facing marine ecosystems, and an attempt to reduce the dangers by educating the public about the impacts of their behavior.
NSDL National Science Digital Library
The National Sea Grant program was established in 1966, and a few years later, the state of New York sponsored the program's first outpost. Currently, the New York Sea Grant (NYSG) is a cooperative program of the State University of New York (SUNY) and Cornell University. On the homepage, visitors can look over sections that include "Extension", "Research", "Education", "Publications", and "Theme Areas". The "Theme Areas" is a good place to start, as it features topical material on coastal processes and hazards, fisheries, and aquatic invasive species. Their helpful publication "Currents" is also worth a look, and it contains materials on grant opportunities, research materials, fact sheets, and public awareness programs. Moving on, the "Related Sites" area contains links to "Hot Topics" (topical news items related to the sea and such) and affiliated organizations.
NSDL National Science Digital Library
In this 6-7 day investigation, learners begin with an introduction to seamounts that are present in the Gulf of Alaska. They learn how seamounts were formed and look at a bathymetric map of a seamount. In Activity 3A, learners explore sea floor mapping techniques as they participate in an activity to create a map of a sea feature they have molded out of clay. In Activity 3B, learners watch a short animated presentation, "Who cares about Sea Floor Mapping?" and create a model of a seamount found in Alaska. They use pre-sonar techniques to collect data and create a graph of their seamount using Excel. This detailed lesson plan includes learner hand-outs, evaluation questions, curricular connections, and tips.
Grant, Alaska S.
We measured apparent marine radiocarbon ages for the Mediterranean Sea, Black Sea, and Red Sea by accel- erator mass spectrometry radiocarbon analyses of 26 modern, pre-bomb mollusk shells collected living between AD 1837 and 1950. The marine reservoir (R(t)) ages were estimated at some 390 ± 85 yr BP, 415 ± 90 yr BP and 440 ± 40 yr BP,
Nadine Tisnerat; Franck Bassinot
NSDL National Science Digital Library
This is the website for the only facility housing a complete collection of Sea Grant funded work. An archive and lending library for reprints, books, reports, maps, newsletters, handbooks, videos, CD-roms and computer programs regarding: oceanography; marine education; aquaculture; fisheries; limnology; coastal zone management; marine recreation and law. Lends documents worldwide, aiding scientists, teachers, students, fishermen and others in research and study. Bibliographic database is searchable from the website, where users may obtain citations, abstracts and access to over 20,000 downloadable texts of Sea Grant publications.
NSDL National Science Digital Library
This activity uses a mix of multimedia resources and hands-on activities to support a storyline of investigation into melting sea ice. The lesson begins with a group viewing of a video designed to get students to consider both the local and global effects of climate change. The class then divides into small groups for inquiry activities on related topics followed by a presentation of the findings to the entire class. A final class discussion reveals a more complex understanding of both the local and global impacts of melting sea ice.
Domain, Wgbh E.
NSDL National Science Digital Library
This National Geographic lesson plan explores bioluminescent organisms in the sea. In this activity, students explore the benefits of bioluminescence by conducting a simulation and viewing pictures of bioluminescent marine animals on the Web. The conclusion of the activity entails students pretending to be deep-sea divers and writing journal entries about their impressions of a bioluminescent animal they have encountered. In addition to a detailed procedure, the lesson plan includes suggestions for assessment, ideas for extending the lesson, and links to related websites.
Long-term variability in Arctic sea surface temperatures
NASA Astrophysics Data System (ADS)
In this study, we used 30 years of an operational sea surface temperature (SST) product, the NOAA Optimum Interpolation (OI) SST Version 2 dataset, to examine variations in Arctic SSTs during the period December 1981-October 2011. We computed annual SST anomalies and interannual trends in SST variations for the period 1982-2010; during this period, marginal (though statistically significant) increases in SSTs were observed in oceanic regions poleward of 60°N. A warming trend is evident over most of the Arctic region, the Beaufort Sea, the Chuckchi Sea, Hudson Bay, the Labrador Sea, the Iceland Sea, the Norwegian Sea, Bering Strait, etc.; Labrador Sea experienced higher temperature anomalies than those observed in other regions. However, cooling trends were observed in the central Arctic, some parts of Baffin Bay, the Kara Sea (south of Novaya Zemlya), the Laptev Sea, the Siberian Sea, and Fram Strait. The central Arctic region experienced a cooling trend only during 1992-2001; warming trends were observed during 1982-1991 and 2002-2010. We also examined a 30-yr (1982-2011) record of summer season (June-July-August) SST variations and a 29-yr (1982-2010) record of September SST variations, the results of which are discussed.
Singh, Rajkumar Kamaljit; Maheshwari, Megha; Oza, Sandip R.; Kumar, Raj
Electromagnetic Phenomena in the Sea.
National Technical Information Service (NTIS)
Contents: Gyrocompass for magnetometric operations in the sea; Measuring the magnetic field in the sea by towed magnetometers; Errors of the ferrosonde component of a magnetometer; Tidal variation of the geomagnetic field on Franz Josef Land; Shock waves ...
V. V. Shuleikin
Sea Gravimetry and Eotvos Correction.
National Technical Information Service (NTIS)
A physical model for sea gravimetry, which includes the Eotvos effect, is derived. An error model for sea gravimetry, which includes Eotvos correction errors, cross coupling errors and off level errors is shown. The possibilities of obtaining ship velocit...
J. H. M. Smit
AMSR-E Arctic Sea Ice: September 2010 to March 2011: Scientists tracking the annual maximum extent of Arctic sea ice said that 2011 was among the lowest ice extents measured since satellites began ...
Nordic Seas dissolved oxygen data in CARINA
NASA Astrophysics Data System (ADS)
Water column data of carbon and carbon relevant hydrographic and hydrochemical parameters from 188 previously non-publicly available cruises in the Arctic, Atlantic, and Southern Ocean have been retrieved and merged into a new database: CARINA (CARbon IN the Atlantic). The data have been subject to rigorous quality control (QC) in order to ensure highest possible quality and consistency. The data for most of the parameters included were examined in order to quantify systematic biases in the reported values, i.e. secondary quality control. Significant biases have been corrected for in the data products, i.e. the three merged files with measured, calculated, and interpolated values for each of the three CARINA regions; the Arctic Mediterranean Seas (AMS), the Atlantic (ATL), and the Southern Ocean (SO). With the adjustments the CARINA database is consistent both internally as well as with GLODAP (Key et al., 2004) and is suitable for accurate assessments of, for example, oceanic carbon inventories and uptake rates and for model validation. The Arctic Mediterranean Seas includes the Arctic Ocean and the Nordic Seas (Greenland, Norwegian, and Iceland Seas), and the quality control was carried out separately in these two areas. This contribution presents an account of the quality control of the dissolved oxygen data from the Nordic Seas in CARINA. Out of the 35 cruises from the Nordic Seas included in CARINA, 32 had oxygen data. The data from 4 of these were found to be biased low and were subject to adjustment. Thus the final CARINA data product contains oxygen data from 32 cruises from the Nordic Seas, and these data appear consistent to ±1% (corresponds to ±3 ?mol kg-1 in the deep water).
Falck, E.; Olsen, A.
NASA Technical Reports Server (NTRS)
The seafloor has a profound role in Arctic sea ice formation and seasonal evolution. Ocean bathymetry controls the distribution and mixing of warm and cold waters, which may originate from different sources, thereby dictating the pattern of sea ice on the ocean surface. Sea ice dynamics, forced by surface winds, are also guided by seafloor features in preferential directions. Here, satellite mapping of sea ice together with buoy measurements are used to reveal the bathymetric control on sea ice growth and dynamics. Bathymetric effects on sea ice formation are clearly observed in the conformation between sea ice patterns and bathymetric characteristics in the peripheral seas. Beyond local features, bathymetric control appears over extensive ice-prone regions across the Arctic Ocean. The large-scale conformation between bathymetry and patterns of different synoptic sea ice classes, including seasonal and perennial sea ice, is identified. An implication of the bathymetric influence is that the maximum extent of the total sea ice cover is relatively stable, as observed by scatterometer data in the decade of the 2000s, while the minimum ice extent has decreased drastically. Because of the geologic control, the sea ice cover can expand only as far as it reaches the seashore, the continental shelf break, or other pronounced bathymetric features in the peripheral seas. Since the seafloor does not change significantly for decades or centuries, sea ice patterns can be recurrent around certain bathymetric features, which, once identified, may help improve short-term forecast and seasonal outlook of the sea ice cover. Moreover, the seafloor can indirectly influence cloud cover by its control on sea ice distribution, which differentially modulates the latent heat flux through ice covered and open water areas.
Nghiem, S. V.; Clemente-Colon, P.; Rigor, I. G.; Hall, D. K.; Neumann, G.
National Sea Grant Educators Network
NSDL National Science Digital Library
Compilation of Sea Grant marine education resources. Site includes the latest news, a pdf file discussing Sea Grant education initiatives, links to all Sea Grant Education websites, several teaching and learning resources, and several interactive classroom activities. An excellent site to begin preparations for a marine science or oceanography course.
Sea Level : Frequently Asked Questions and Answers
NSDL National Science Digital Library
Visitors can find answers to frequently asked questions regarding sea level and sea level changes. Topics addressed include how mean sea level is defined, how much sea level would rise if all the worlds ice were to melt, differences in sea level between oceans and at different latitudes, the meaning of altitude above sea level, and others.
NSDL National Science Digital Library
This activity integrates art and science as students use books and other sources to learn more about the creatures that live in the ocean. Once they have learned about various sea creatures and their habitats, they will construct an undersea environment in their classroom.
National Technical Information Service (NTIS)
The U.S. Coast Guard (CG) Research & Development Center (R&DC) evaluated the U.S. Navy's Sea Fighter vessel (FSF-1) for potential applicability for CG missions. For this evaluation, the project team used a combination of engagement modeling and simulation...
M. Hammond
An open sea skimmer barge for use as a dredge comprising a hull having a bow, bottom, side walls, stern having a substantially horizontal elongate slot extending across a portion thereof and a deck, a spill suction tunnel, a collection tank, secondary oil separation means and tertiary oil separation means.
Ayers, W.M.
An open sea skimmer barge comprising a hull having a bow, bottom, side walls, stern having a substantially horizontal elongate slot extending across a portion thereof and a deck, a spill suction tunnel, a collection tank, secondary oil separation means and tertiary oil separation means.
Ayers, W.M.; Maheshwary, A.K.; Young, P.J.
An open sea skimmer barge is disclosed comprising a hull having a bow, bottom, side walls, stern having a substantially horizontal elongate slot extending across a portion thereof and a deck, a suction tunnel, a collection tank, secondary oil separation means and tertiary oil separation means.
Ayers, W.M.
NSDL National Science Digital Library
Story of the invasion of jellyfish into the Black Sea and the resulting affects on the native fish population. An excellent introduction into introduced species and their effects on an ecosystem. Site features an abundance of information on alien species and the delicacy that goes into eradicating them. Also links to additional non-traditional science-related news events.
NSDL National Science Digital Library
Although most students do not have the opportunity to conduct in situ research projects until college, the Classroom of the Sea program at the American School for the Deaf (ASD) provides an unusual opportunity for students to work directly with scientists
Monte, Denise; Hupper, Mary L.; Scheifele, Peter
NSDL National Science Digital Library
Explore the relationship between sea surface temperature (SST) and Earth's climate system, and consider the effects that changes in SST are having in the Arctic and beyond in this interactive activity produced for Teachers' Domain featuring data and visualization from NOAA.
Foundation, Wgbh E.
NSDL National Science Digital Library
In the past century, as the climate has warmed, sea level rise has accelerated. Scientists predict it will only increase, and they're studying changes in the ocean and land to better understand how and why the water is rising. "Changing Planet" is produced in partnership with the National Science Foundation.
Learn, Nbc
National Technical Information Service (NTIS)
A study of circulation in the Alboran Sea begins by using simplest model capable of simulating major features of the circulation. This is a reduced gravity model in a semi-enclosed rectangular domain. It is essentially a model of the first baroclinic mode...
R. H. Preller
ERIC Educational Resources Information Center
Introduces the Sea Program in which participant students were deaf and collaborated with a bioacoustician. Studies the underwater noise levels of the Gulf of Maine and the possible impacts on marine life. Explains implementing this project in the science curriculum. (YDS)
Hupper, Mary Laporta; Monte, Denise; Scheifele, Peter
NSDL National Science Digital Library
A multimedia public education project designed to raise awareness of the world ocean and the life within it. Find articles on the latest ocean issues, links to resources and audio clips of the radio show Ocean Report. Also features information on SeaWeb programs, such as aquaculture initiatives for both fish and their eggs (caviar), and publications.
ERIC Educational Resources Information Center
In their preoccupation with highly complex new energy systems, scientists and statesmen may be overlooking the possibilities of Ocean Thermal Energy Conversion (OTEC). That is the view of a Carnegie-Mellon University physicist who is in the forefront of solar sea power investigation. (Author/BT)
Zener, Clarence
NSDL National Science Digital Library
This radio broadcast discusses the recent issue of the increase and spread of tunicates (or 'sea squirts'), who have suddenly proliferated off the Atlantic Coast of the United States and Canada. The creatures, an invasive species likely from Asia or Europe, have carpeted the ocean floor and are smothering valuable shellfish.
Hoops, Richard
ERIC Educational Resources Information Center
This lesson contains materials for the U.S. Navy Museum's "Ships to the Sea" program. The program is appropriate for students in grades 2-4 and was designed in accordance with local and national social studies standards. The materials introduce students to the world of ship technology and naval terminology. The lesson is presented in five…
Department of the Navy, Washington, DC.
ERIC Educational Resources Information Center
Florida has initiated a training program in an entirely new dimension--Sea Farming. Presented is a description of the vocational agriculture program designed to teach propagation, cultivation, harvesting, marketing, and conservation practices related to production of oysters, shrimp, scallops, crabs, and fin fishes. (Editor/GB)
Morgan, William
NSDL National Science Digital Library
This interactive program focuses on the role of sea level in climate change. Sections include an overview and a list of relevant NASA satellite missions and their objectives. A third section, entitled Global View, covers the following 5 topics: Latest View, Large El Niño, Hurricane Katrina, Indian Ocean Tsunami, and La Niña.
National Technical Information Service (NTIS)
There exists a need in the oceanography community to be able to produce climatologies of remote or poorly sampled shallow water areas through remote sensing techniques. Our goal was to construct a three-dimensional thermal structure of the Yellow Sea base...
C. R. Fralick
Sea floor magnetic observatory
NASA Astrophysics Data System (ADS)
The electromagnetic precursors of seismic hazards are widely accepted as strong evidence of the approaching earthquake or volcano eruption. The monitoring of these precursors are of main interest in densely populated areas, what creates serious problems to extract them at the strong industrial noise background. An interesting possibility to improve signal-to-noise ratio gives the installation of the observation points in the shelf zones near the possible earthquake places, what is fairly possible in most seismically active areas in Europe, e. g. in Greece and Italy. The serious restriction for this is the cost of the underwater instrumentation. To realize such experiments it requires the unification of efforts of several countries (e. g., GEOSTAR) or of the funds of some great companies (e. g., SIO magnetotelluric instrument). The progress in electronic components development as well as the appearance of inexpensive watertight glass spheres made it possible to decrease drastically the price of recently developed sea floor magnetic stations. The autonomous vector magnetometer LEMI-301 for sea bed application is described in the report. It is produced on the base of three-component flux-gate sensor. Non-magnetic housing and minimal magnetism of electronic components enable the instrument to be implemented as a monoblock construction where the electronic unit is placed close to the sensor. Automatic circuit provides convenient compensation of the initial field offset and readings of full value (6 digits) of the measured field. Timing by internal clock provides high accuracy synchronization of data. The internal flash memory assures long-term autonomous data storage. The system also has two-axes tilt measurement system. The methodological questions of magnetometer operation at sea bed were studied in order to avoid two types of errors appearing at such experimental cases. First is sea waving influence and second one magnetometer orientation at its random positioning on the sea floor in order to get experimental data in geomagnetic coordinates frames. The analysis executed showed that first error source can not be avoided at shallow water experiments but can be easily taken into account. The special methodology and the developed software allowed to solve the second problem. It was shown that it is possible to reduce the magnetometer data collected in randomly oriented coordinate system at arbitrary position on the sea floor to the data in the frame system connected with geomagnetic coordinates. The parameters of LEMI-302 sea bed magnetometer are discussed and the experimental results of its application are presented. The research work in Ukraine was partly supported by INTAS grant 99-1102.
Korepanov, V.; Prystai, A.; Vallianatos, F.; Makris, J.
Sea-Level Projections from the SeaRISE Initiative
NASA Technical Reports Server (NTRS)
SeaRISE (Sea-level Response to Ice Sheet Evolution) is a community organized modeling effort, whose goal is to inform the fifth IPCC of the potential sea-level contribution from the Greenland and Antarctic ice sheets in the 21st and 22nd century. SeaRISE seeks to determine the most likely ice sheet response to imposed climatic forcing by initializing an ensemble of models with common datasets and applying the same forcing to each model. Sensitivity experiments were designed to quantify the sea-level rise associated with a change in: 1) surface mass balance, 2) basal lubrication, and 3) ocean induced basal melt. The range of responses, resulting from the multi-model approach, is interpreted as a proxy of uncertainty in our sea-level projections. http://websrv.cs .umt.edu/isis/index.php/SeaRISE_Assessment.
Nowicki, Sophie; Bindschadler, Robert
NASA Technical Reports Server (NTRS)
[figure removed for brevity, see original site]Our topic for the weeks of April 4 and April 11 is dunes on Mars. We will look at the north polar sand sea and at isolated dune fields at lower latitudes. Sand seas on Earth are often called 'ergs,' an Arabic name for dune field. A sand sea differs from a dune field in two ways: 1) a sand sea has a large regional extent, and 2) the individual dunes are large in size and complex in form. This VIS image was taken at 82 degrees North latitude during Northern spring. The image is completely dominated by dunes. In sand seas, it is very common for a single type of dune to occur, and for a single predominate wind to control the alignment of the dunes. Image information: VIS instrument. Latitude 82.2, Longitude 152.5 East (207.5 West). 19 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.
Sea ice radiative forcing, sea ice area, and climate sensitivity
NASA Astrophysics Data System (ADS)
Changes in sea ice cover affect climate sensitivity by modifying albedo and surface heat flux exchange, which in turn affect the absorbed solar radiation at the surface as well as cloud cover, atmospheric water content and poleward atmospheric heat transport. Here, we use a configuration of the Community Earth System Model 1.0.4 with a slab ocean model and a thermodynamic-dynamic sea ice model to investigate the overall net effect of feedbacks associated with the sea ice loss. We analyze the strength of the overall sea ice feedback in terms of two factors: the sensitivity of sea ice area to changes in temperature, and the sensitivity of sea ice radiative forcing to changes in sea ice area. In this model configuration, sea ice area decreases by ~3 × 1012 m2 per K of global warming, while the effective global radiative forcing per square meter of sea ice loss is ~0.1 × 10-12 W m-2. The product of these two terms (~0.3 W m-2 K-1) approximately equals the difference in climate feedback parameter found in simulations with sea ice response (1.05 W m-2 K-1) and simulations without sea ice response (1.31 W m-2 K-1 or 1.35 W m-2 K-1, depending on the method used to disable changes in sea ice cover). Thus, we find that in our model simulations, sea ice response accounts for about 20% to 22% of the climate sensitivity to an imposed change in radiative forcing. In our model, the additional radiative forcing resulting from a loss of all sea ice in the 'pre-industrial' state is comparable to but somewhat less than the radiative forcing from a doubling of atmospheric CO2 content.
Caldeira, Ken; Cvijanovic, Ivana
NASA Astrophysics Data System (ADS)
The North Sea is a semi-enclosed shelf sea attached to the North-east Atlantic and in its south-eastern part receives significant matter from river discharge and atmospheric deposition: Anthropogenic nutrients, dissolved carbon and organic compounds have elevated pristine background concentrations in the coastal strip of the North Sea since about 250 years as a consequence of intensified agriculture and industrialisation since then, In such a marine environment the legacy of old inputs and the influence of processes in the sediment on the biogeochemistry of the overlying water column increases with decreasing water depth. On the other hand the flux of particulate organic matter into the surface sediment (~15 cm depth) also increases with decreasing water depth or distance from the coast. Both effects are also described by results of ECOHAM-M simulations, the coupled pelagic-benthic ecosystem model that includes a prognostic multi-layer sediment module adopted from the global biogeochemical model HAMOCC as part of the MPI-earth-system model (MPI-ESM).The transfer from deep sea to coastal applications required different adaptations, such as changes in porosity values, in dissolution and organic matter remineralisation rates, and stoichiometries. In the model, two pelagic detritus pools, one slowly sinking with semi-labile organic matter, and one fast sinking with labile organic matter are collected in one sediment pool. After a spin-up of several hundred years the 3d-coupled model for the southern and central North Sea attains equilibrium, where the local inputs and outputs of the pelagic and benthic module are balanced. From this equilibrium state we initialised a realistic decadal run (2000-2009). Analysing the seasonal and interannual model results we found that the variability of sediment efflux in the model is low compared to the more dynamic pelagic system components, but simulated (and observed) sediment pore water profiles clearly show concentration gradients from the coast into the central North Sea. Data on organic matter concentration and quality in surface sediments along a comparable transect suggest that not only the loading with POM decreases with distance to land, but also the reactivity of organic matter, indicated by amino acid composition as a measure of the degree of protein degradation. This ageing or degradation effect can also be seen in a near-shore surface sediment core where the C/N ratio increases with depth, while the relative concentration of labile material in sedimentary organic matter decreases. We discuss how the quality of organic particulate matter could be integrated into the sediment model equations.
Paetsch, Johannes; Kuehn, Wilfried; Serna, Alexandra; Lahajnar, Niko; Emeis, Kay
Assessment of 137Cs and 90Sr fluxes in the Barents Sea
NASA Astrophysics Data System (ADS)
The annual balance of radionuclides inflow/outflow was assessed for 137Cs and 90Sr isotopes in the Barents Sea, taking into account the atmospheric precipitation, inflow from the Norwegian and the White seas, as well as riverine discharge, liquid radioactive waste disposal (LRWD), and outflow to the adjacent seas. The original and published data for the period of 1950-2009 were analyzed. According to the multiyear dynamics (1960-2009), the inflow of 137Cs and 90Sr into the Barents Sea was significantly preconditioned by the Norwegian Sea currents; and precipitation played a major role in the 1950s, 1960s, and in 1986. Currently, the trans-border redeposition of 90Sr prevails over 137Cs redeposition in the Barents Sea, and constitutes about 99% of inflow of each element.
Matishov, G. G.; Matishov, D. G.; Usyagina, I. S.; Kasatkina, N. E.; Pavel'Skaya, E. V.
NSDL National Science Digital Library
This site features a video that illustrates both seasonal patterns and long-term changes in sea ice distribution across the Arctic Ocean. It draws data from two satellite instruments that measure emitted microwave radiation, which helps distinguish open ocean from ice. It shows that during the winter months, a layer of ice forms across vast expanses of the Arctic Ocean and each summer, more than half of that ice vanishes. Students discover that this natural cycle of freezing and thawing is influenced both by seasonal temperature variations and long-term climate change and that scientists are using satellite images to measure the distribution of Arctic sea ice in order to gain a better understanding of how it is linked to Earth's climate system.
NSDL National Science Digital Library
Dauphin Island Sea Lab is Alabama's marine education and research center. Lab also provides a public aquarium that focuses solely on the native eco-systems of the Mobile Bay estuary. Site provides information on graduate programs, undergraduate opportunities, faculty, facilities, and news and events. Explore the Education and Aquarium sections for teacher resources and information on workshops, student summer camps, and academic-year programs.
NSDL National Science Digital Library
At-sea education program combines classroom study with shipboard science studies in Puget Sound, Washington. Offers spring programs for schools and home schoolers, summer programs for families and youngsters; expeditions of 1 to 5 days involve oceanographic sampling activities, navigation and sailing responsibilities aboard a 61-foot sailing vessel. Teachers can join a preview sail to evaluate; site provides details on water quality, plankton and other studies and equipment used.
Pycnogonids (sea spiders) are marine arthropods numbering some 1,160 extant species. They are globally distributed in depths of up to 6,000metres, and locally abundant; however, their typically delicate form and non-biomineralized cuticle has resulted in an extremely sparse fossil record that is not accepted universally. There are two opposing views of their phylogenetic position: either within Chelicerata as sister group
Derek J. Siveter; Mark D. Sutton; Derek E. G. Briggs; David J. Siveter
Dead Sea rhodopsins revisited.
The Dead Sea is a unique hypersaline ecosystem with near toxic magnesium levels (?2?M), dominance of divalent cations and a slightly acidic pH. Previously, we reported a haloarchaeon related to Halobacterium salinarum to dominate in a microbial bloom that developed in 1992 in the upper water layers of the lake following massive freshwater runoff. Whether this clade also dominated an earlier bloom in 1980-1982 cannot be ascertained as no samples for cultivation-independent analysis were preserved. The presence of the light-driven proton pump bacteriorhodopsin was reported in the 1980-1982 bloom of prokaryotes that had developed in the Dead Sea. To test the hypothesis that bacteriorhodopsin proton pumping may play a major role in determining what type of haloarchaea may dominate in specific bloom conditions, we compared rhodopsin genes recovered from Dead Sea biomass collected in different periods with genes coding for retinal proteins in isolated haloarchaea. Novel bacteriorhodopsin and sensory rhodopsin genes were found in samples collected in 2007 and 2010. The fact that no rhodopsin genes were recovered from samples collected during the 1992 bloom, which was dominated by a single species, suggests that different clades were present in the 1980-1982 and 1992 blooms, and that bacteriorhodopsin proton pumping did not necessarily play a determinative role in the dominance of specific halophiles in the blooms. PMID:23760932
Bodaker, Idan; Suzuki, Marcelino T; Oren, Aharon; Béjà, Oded
NASA Technical Reports Server (NTRS)
On July 25, 2006, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), flying on NASA's Terra satellite, captured this image of the Curonian (or Courland)spit, the Curonian Lagoon (also known as the Courland Lagoon) it encloses, and part of the Baltic Sea. Just 3,800 meters (about 12,460 feet) at its widest point, the spit encloses a lagoon of some 1,620 square kilometers (625 square miles). In this image, dark blue indicates deep water, and lighter blue indicates shallow and/or sediment-laden water. Different shades of blue distinguish the deeper Baltic Sea and the shallower Curonian Lagoon. Vegetation appears in varying shades of green, paved surfaces and bare ground appear in shades of beige and gray, and sandy areas appear off-white. Obvious sandy areas appear along the length of the spit. On the Baltic Sea side, a thin off-white band of beach runs the length of the spit; on the Curonian Lagoon side, intermittent beaches carve their way into the narrow strip of land.
Kara Sea radioactivity assessment.
Investigations following five international expeditions to the Kara Sea have shown that no radiologically significant contamination has occurred outside of the dumping sites in Novaya Zemlya bays. Increased levels of radionuclides in sediment have only been observed in Abrosimov and Stepovoy Bays very close to dumped containers. Evaluations of radionuclide inventories in water and sediment of the open Kara Sea and Novaya Zemlya bays as well as soil from the shore of Abrosimov bay have shown that radionuclide contamination of the open Kara Sea is mainly due to global fallout, with smaller contributions from the Sellafield reprocessing plant, the Chernobyl accident run-off from the Ob and Yenisey rivers and local fallout. Computer modelling results have shown that maximum annual doses of approximately 1 mSv are expected for a hypothetical critical group subsisting on fish caught in the Novaya Zemlya bays whereas populations living on the mainland can be expected to receive doses at least three orders of magnitude lower. PMID:10568274
Osvath, I; Povinec, P P; Baxter, M S
NSDL National Science Digital Library
The Aral Sea is actually not a sea at all, but an immense fresh water lake. In the last thirty years, more than sixty percent of the lake has disappeared because much of the river flow feeding the lake was diverted to irrigate cotton fields and rice paddies. Concentrations of salts and minerals began to rise in the shrinking body of water, leading to staggering alterations in the lakes ecology and precipitous drops in the Arals fish population. Powerful winds that blow across this part of Asia routinely pick up and deposit the now exposed lake bed soil. This has contributed to a significant reduction in breathable air quality, and crop yields have been appreciably affected due to heavily salt laden particles falling on arable land. This series of Landsat images taken in 1973, 1987 and 2000 show the profound reduction in overall area at the north end of the Aral, and a commensurate increase in land area as the floor of the sea now lies exposed.
Thomson, Joycelyn; Mitchell, Horace; Williams, Darrel
NASA Technical Reports Server (NTRS)
The surface waters of the Bering Sea around the Pribilof Islands, off Alaska's west coast, exhibited a dark green color on May 15, 2002, in this SeaWiFS true-color image. The green color of the currents there suggests the presence of a large phytoplankton bloom. Careful inspection reveals some a reddish tinges of light reflected by this bloom, particularly in a long east to west band just south of the Pribilof Islands, and just north of the Aleutian Island chain (disappearing toward the lower righthand corner of this scene beneath the cloud bank). Some scientists speculate this could be another Phaeocystis bloom, similar to the bloom of this species that was observed in these waters roughly this time last year. Such blooms are typically accompanied by a strong, unpleasant odor in the immediate vicinity. The light brown color of the surface waters along the Alaskan shoreline are probably due to suspended sediments washed off from the land. Image courtesy the SeaWiFS Project, NASA GSFC, and ORBIMAGE
NSDL National Science Digital Library
The National Maritime Museum (NMM) in England notes that its goal is "working to illustrate for everyone the importance of the sea, ships, time and the stars and their relationship with people." There is so much to explore in the "Sea and Ships" portion of the NMM website, but a great way to see everything it has to offer is by using the "Sea and Ships Directory" at the bottom of the homepage. It divides the material up by "Subjects", "People", "Collections", "Online Galleries", and "Games and Interactives". Visitors interested in lessons about the ocean that come in the form of games, quizzes and stories, should definitely check out the "Your Ocean" link from the "Games and Interactives". The "Your Waste" lesson gives visitors the opportunity to test their skills at "managing an oil spill clean-up operation", in the game "Oil Crisis!" Keeping waste to a minimum is what the quiz "Pollution Solutions" addresses, and is also on the "Your Waste" page. Other lessons include "Your Energy", "Your Stuff" and "Your Climate".
Long Term Variability of Sea Surface Temperature in Mediterranean Sea
NASA Astrophysics Data System (ADS)
The long term variability of the sea surface temperature (SST) of the Mediterranean basin and its sub-basins for the period 1869-2006 (138 years) is investigated using the International Comprehensive Ocean-Atmosphere Data Set (I-COADS). Analysis of the SST time-series revealed a positive trend in both basin and sub-basin scale. During the last century, the highest positive SST trend is found in the Adriatic Sea (0.0141° C/y) and the lowest one in the Aegean sea (0.0011° C/y). This difference in the SST evolution in the two sub-basins can be related to the shift of the Eastern Mediterranean deep water formation site during the 90s, known as Eastern Mediterranean Transient (EMT). The SST variations of the Eastern Mediterranean sub-basins (Adriatic Sea, Ionian Sea, Aegean Sea, Levantine Sea) are highly correlated to each other, in contrast to the poor correlation of the SST variations between the Eastern and Western Mediterranean Sea. Harmonic analysis has shown that a dominant period of the Mediterranean variability is similar to the deep water turnover time of the basin. Comparison with climatic indices points out a high correlation of the Western Mediterranean and Adriatic Sea SST with the NAO index, while the Eastern Mediterranean SST variations are highly correlated to the Indian Summer Monsoon Index.
Axaopoulos, P.; Sofianos, S.
Isotope studies in the Caspian Sea
Oceanographic and isotopic investigations in the Caspian Sea and the analyses of the available data on the discharge to the sea and the observed sea level changes suggest that climatically caused changes of river inflow are the major cause of the sea level fluctuations over the last century. Hydrogen-3 and 3H–3He data indicate that the deep basins of the sea
K. Froehlich; K. Rozanski; P. Povinec; B. Oregioni; J. Gastaud
The USGS Salton Sea Science Office
The U.S. Geological Survey's (USGS) Salton Sea Science Office (SSSO) provides scientific information and evaluations to decisionmakers who are engaged in restoration planning and actions associated with the Salton Sea. The primary focus is the natural resources of the Salton Sea, including the sea?s ability to sustain biological resources and associated social and economic values.
Case, Harvey Lee, III; Barnum, Douglas A.
Sea Otter, River Otter. The Wonder Series.
ERIC Educational Resources Information Center
This curriculum guide is all about otters and provides information on both sea and river otters. Included are activities related to the diet of sea otters, the adaptations sea otters have made to live in the sea, their tool-using abilities, where they live and how to spot them, comparative anatomy of sea and river otters, and otter movement. The…
Robinson, Sandra Chisholm
The Baltic Sea Basin: Introduction
\\u000a The Baltic Sea Basin serves as an example of a region where the use of natural resources and the need of environmental protection\\u000a require a comprehensive and holistic approach in terms of geosciences, environmental sciences, and socio-economics. In this\\u000a book, authors from countries around the Baltic Sea and overseas shed light on the Baltic Sea Basin with respect to (1)
Jan Harff; Svante Björck; Peer Hoth
NSDL National Science Digital Library
Used in combination with the Sea Scallop Shell Lab teacher's guide, students will examine sea scallop shells to figure out as much as possible about the scallops living on the sea floor in one three important fishery grounds, Hudson Canyon, off New Bedford, MA, and George's Bank. The activity emphasizes observation, measurements, and basic calculations. The teacher's guide is available from the COSEE-NE OSEI resource site.
Aerosols Over Yellow Sea Sediments
NASA Technical Reports Server (NTRS)
This SeaWiFS image shows complex phytoplankton distribution patterns in the Bohai and Yellow seas. A wide band of brownish water along the coast north and south of the mouth of the Yangtze River indicates a heavy load of suspended sediment. The air over eastern central China and the Yellow Sea is thick with aerosols. Farther north over the Manchurian Plain and Greater Khingan Range, the air is much clearer.
Sea Salt Source Function over the Baltic Sea
NASA Astrophysics Data System (ADS)
Studies of production and transport of aerosol over the sea are very important for many areas of knowledge. Marine aerosol emitted from the sea surface helps to clean the boundary layer from other aerosol particles. The emitted droplets do not dry out in the highly humid surface layer air and because of their sizes most of them are deposited quickly at the sea surface. Therefore, marine aerosol has many features of rain i.e. the deposition in the marine boundary layer in high wind events is controlled not only by the "dry" processes but also by the "wet" scavenging. While many cruises conducted on board S/Y Oceania, we collected many data which were used to calculate sea salt source function over the Baltic Sea. Our cruises held between 2009 and 2012. Measurements were carried out using gradient method. For this method we used Laser Particle Counter (PMS model CSASP-100_HV) placed on one oft the mast of S/Y Oceania. Measurements were performed on five different levels around sea level: 8, 11, 14, 17 and 20 meters. Based on the averaged vertical concentration, profiles were calculated, using Monin-Obuchow theory, vertical sea spray fluxes in the near water layer. Based on fluxes calculated from vertical concentration profiles was calculated sea salt source function over the Baltic Sea. This function gives emission for different particle size, depending on environmental parameters. Emission of sea spray depends of the size of energy lost by the wind waves in process of collapse. Acknowledgements: The support for this study was provided by the project Satellite Monitoring of the Baltic Sea Environment - SatBa?tyk founded by European Union through European Regional Development Fund contract No. POIG 01.01.02-22-011/09.
Petelski, Tomasz; Makuch, Przemyslaw; Markuszewski, Piotr; Jankowski, Andrzej; Zieli?ski, Tymon
Regime shifts in North Sea and Baltic Sea: A comparison
NASA Astrophysics Data System (ADS)
The ICES subdivisions in the North Sea (SD IIIa, SD IVa, and SD IVb) and the subdivisions in the Baltic Sea (SD 29, SD 27/28-2, and SD 25/26) are selected to compare the response in long term monitoring data (1970-2000) with respect to climate regime shifts. A modified AMOEBA model is applied to the data sets to identify the status and development of the North Sea and Baltic Sea system during two recent regime shifts. Biological regime shifts can be identified 1989/1990 in SD IIIa in the North Sea and in SD 25/26 in the Baltic Sea. A synchronous appearance of regime shifts could only be identified in the central and southern Baltic Sea for both regime shifts 1975/76 and 1989/90 where the AMOEBA model indicated a high similarity in ecosystem response. A clear difference was identified in the response of the North Sea and the Baltic Sea. Inter-annual and inter-decadal variability as well as regime shifts are driven in the Baltic Sea by direct atmospheric forcing only. In contrast, the changes in the North Sea are influenced by both the direct atmospheric forcing and the indirect forcing from the changes in North Atlantic. The fact that regime shifts as well as their synchronous appearance can be identified with the AMOEBA model might be of major interest for the management of sustainable use of ecosystem goods and services, the development of ecosystem approach to management and the implementation of the Marine Strategy Framework Directive (MSFD) of the European Union (EU).
Dippner, Joachim W.; Möller, Caroline; Hänninen, Jari
NSDL National Science Digital Library
This activity has students apply scientific theory and hypothesis to studies being conducted in the Black Sea. They will discuss the purpose of and theory behind the Black Sea study and use maps to explain the flood theory. Students will also write hypotheses suggesting what certain pieces of evidence might reveal about the Black Sea and the flood. Next, they will read about the researchers' discoveries and list the items they found. Students will conclude by writing plans, pretending they are going to lead the next Black Sea expedition, and hypothesizing what they might find and what those findings might signify.
NSDL National Science Digital Library
This is the companion Web site to "Deep Sea Invasion," a PBS NOVA documentary broadcast April 1, 2003. The program follows marine biologist Alexandre Meinesz and his scientific detective work to explain the rampant spread of the tropical alga Caulerpa taxifolia through the Mediterranean and his struggle to instigate control efforts. The features of this Web site include a timeline chronicling the invasion, an article by Meinesz on the impact of invasive species, another article addressing strategies for controlling invasives, and an interactive quiz in which users match up species with their invasive characteristics. With interesting material covering a range of ecological topics, this Web site should be of interest to any reader.
NSDL National Science Digital Library
This comprehensive site contains information about both astronomy and the oceans. The Sky section contains astronomical resources, news links, an image gallery, games and general links for more information. The Cosmos contains details about stars, planets, moons, pulsars, galaxies, black holes, quasars, star clusters, nebulas, dark matter and constellations. There is also a section about astronomers and a timeline of space exploration. The Sea section contains news links, aquarium resources, an image gallery, games and links for more information about the oceans. The Ocean Realm highlights the many creatures that live in the oceans. There are also details about ocean exploration and an exploration timeline.
Knight, J.
NASA Astrophysics Data System (ADS)
Published in 1951, The Sea Around Us is one of the most remarkably successful books ever written about the natural world. Rachel Carson's rare ability to combine scientific insight with moving, poetic prose catapulted her book to first place on The New York Times best-seller list, where it enjoyed wide attention for thirty-one consecutive weeks. It remained on the list for more than a year and a half and ultimately sold well over a million copies, has been translated into 28 languages, inspired an Academy Award-winning documentary, and won both the 1952 National Book Award and the John Burroughs Medal. This classic work remains as fresh today as when it first appeared. Carson's writing teems with stunning, memorable images--the newly formed Earth cooling beneath an endlessly overcast sky; the centuries of nonstop rain that created the oceans; giant squids battling sperm whales hundreds of fathoms below the surface; and incredibly powerful tides moving 100 billion tons of water daily in the Bay of Fundy. Quite simply, she captures the mystery and allure of the ocean with a compelling blend of imagination and expertise. Reintroducing a classic work to a whole new generation of readers, this Special Edition features a new chapter written by Jeffrey Levinton, a leading expert in marine ecology, that brings the scientific side of The Sea Around Us completely up to date. Levinton incorporates the most recent thinking on continental drift, coral reefs, the spread of the ocean floor, the deterioration of the oceans, mass extinction of sea life, and many other topics. In addition, acclaimed nature writer Ann Zwinger has contributed a brief foreword. Today, with the oceans endangered by the dumping of medical waste and ecological disasters such as the Exxon oil spill in Alaska, this illuminating volume provides a timely reminder of both the fragility and the importance of the ocean and the life that abounds within it. Anyone who loves the sea, or who is concerned about our natural environment, will want to read this classic work.
Carson, Rachel L.
NSDL National Science Digital Library
SeaWeb is a project designed to raise awareness of the world's oceans and the lifeforms within them, and to encourage conservation efforts. Information provided here includes the latest news about ocean-related issues, audio files of the Ocean Report which provides a tour of the world's oceans, email updates, a bookstore, and an on-line book about issues facing our oceans. This includes habitats, fisheries and other issues. This site is searchable and provides links and resources for further information.
NSDL National Science Digital Library
Researchers at the University of North Carolina are studying how loggerhead and other sea turtles use the Earth's magnetic field for a journey of thousands of miles around the Atlantic Ocean. The turtles react to the Earth's magnetic field as they navigate a five-to-10-year journey that takes them from the east coast of the United States to the coast of Portugal, south toward the west coast of Africa, then back toward the beach where they were born. A better understanding of this turtle ability could help in research of both animal and human navigation.
Black Sea and Caspian Sea, Symposium II, Constanta, Romania.
National Technical Information Service (NTIS)
These proceedings are from the Second Symposium on Black Sea and Caspian Sea Security Issues conducted 18-23 May 2007 in Constanta, Romania. This continued the plan of having a forum for military intelligence chiefs with an interest in the region. The res...
Albedo of summer snow on sea ice, Ross Sea, Antarctica
Surface all-wave albedo and physical parameters (grain radius, mass density, surface temperature, and stratification) of an austral summer snow cover on sea ice were measured in the Ross Sea during January-February 1999. It was observed that (1) from north to south the snow surface temperature decreases, albedo increases, snow mass density decreases, snow composite grain radius decreases, and number density
Xiaobing Zhou; Shusun Li; Kim Morris; Martin O. Jeffries
Structural Framework of East China Sea and Yellow Sea.
National Technical Information Service (NTIS)
A geophysical survey of the East China Sea, Yellow Sea, and Ryukyu Island arc and trench was conducted during Oct.-Nov. 1968 by the U.S. Naval Oceanographic Office. More than 12,000 km of continuous seismic reflection profiling, magnetic, and bathymetric ...
J. M. Wageman T. W. C. Hilde K. O. Emery
59 FR- Atlantic Sea Scallop Fishery
Federal Register 2010, 2011, 2012, 2013
...080593A] RIN 0648-AC99 Atlantic Sea Scallop Fishery AGENCY: National Marine Fisheries...Management Plan (FMP) for the Atlantic Sea Scallop Fishery. Amendment 4 substantially revises the management of the Atlantic Sea Scallop Fishery, especially regarding...
Intraseasonal sea surface temperature variability in Indonesian seas
NASA Astrophysics Data System (ADS)
The satellite-derived sea surface temperature (SST) data, 1998-mid 2012, are used to examine intraseasonal variability (ISV; 20-90 days) across the Indonesian seas. The most energetic ISV is observed in the Banda Sea and across the Indo-Australia basin with an The satellite-derived sea surface temperature (SST) data, 1998-mid 2012, are used to examine intraseasonal variability (ISV; 20-90 days) across the Indonesian seas. The most energetic ISV is observed in the Banda Sea and across the Indo-Australia basin with an average SST standard deviation (STD) between 0.4-0.5°C, with strongest signature during boreal winter. What physical processes force the SST ISV variability within the Indonesian seas? Ocean process, sea-air interaction, or both? To help identify the main forcing, the satellite derived outgoing longwave radiation (OLR) and wind stress data in the region are examined. The OLR shows robust intraseasonal variations and is significantly correlated with the SST, particularly for variability with periods of 30-60 days, with OLR accounting for ~60-70% of the SST variance. The OLR is also maximum during boreal winter. Conversely, the surface wind may play insignificant role in perturbing the SST at intraseasonal timescales as shown by weak correlation between wind stress and SST. We thus suspect that the surface solar flux (suggested by the OLR) is likely more dominant than the surface turbulent heat flux (indicated by the surface wind) as the main source for the ISV in the SST in Indonesian seas. Furthermore the maximum OLR phase, coupled with a period of minimum mixed layer depth, may explain the strong SST variation during boreal winter in Indonesian seas. The influence of the Madden-Julian Oscillation (MJO) on the OLR and SST variability is currently being evaluated.
Napitu, A. M.; Gordon, A. L.; Yuan, X.
Sea-salt aerosol forecasts: evaluation in the open sea
NASA Astrophysics Data System (ADS)
Marine aerosols produced by sea-waves and associated winds are a potentially important climate forcing factor. Acting as efficient cloud condensation nuclei, marine sea-salt aerosols (SSA) could affect cloud formation and precipitation processes. In spite of the importance of impact of SSA variations on climate change, there are no regular sea-salt aerosol measurements in the open sea, where SSA are mainly produced and where their effects on climate are maximal. In order to partly fill the gap in our understanding of the SSA processes, model-based daily forecasts of three-dimensional distribution of SSA could be helpful, providing valuable information about space and time distribution of these types of aerosol. Model performance over the open sea has been verified in this study by comparing modeled SSA concentrations with observed wave height. Two sea-wave monitoring buoys, located in the Eastern Mediterranean near Haifa and Ashdod, provided us with information about wave height during the three-year period, from 2006 - 2008. In the winter months, when local sea-breezes were insignificant, the two buoys measured sea-waves created by synoptic-scale westerlies associated with the transit of cyclones across the Mediterranean: these conditions were similar to the conditions in the open sea. Numerical simulations of SSA were compared with observed wave height on a daily basis. The comparison showed that a high correlation between observed wind speed and wave height was accompanied by a high correlation between wave height and modeled SSA concentrations. This indicates that the model is capable of producing realistic variations of SSA concentrations over the open sea, in line with observed wind speed and wave height.
Kishcha, Pavel; Nickovic, Slobodan; Agnon, Yehuda; Alpert, Pinhas
NASA Astrophysics Data System (ADS)
More and more defence and civil applications require simulation of marine synthetic environment. Currently, the "Future Anti-Surface-Guided-Weapon" (FASGW) or "anti-navire léger" (ANL) missile needs this kind of modelling. This paper presents a set of technical enhancement of the SE-Workbench that aim at better representing the sea profile and the interaction with targets. The operational scenario variability is a key criterion: the generic geographical area (e.g. Persian Gulf, coast of Somalia,...), the type of situation (e.g. peace keeping, peace enforcement, anti-piracy, drug interdiction,...)., the objectives (political, strategic, or military objectives), the description of the mission(s) (e.g. antipiracy) and operation(s) (e.g. surveillance and reconnaissance, escort, convoying) to achieve the objectives, the type of environment (Weather, Time of day, Geography [coastlines, islands, hills/mountains]). The paper insists on several points such as the dual rendering using either ray tracing [and the GP GPU optimization] or rasterization [and GPU shaders optimization], the modelling of sea-surface based on hypertextures and shaders, the wakes modelling, the buoyancy models for targets, the interaction of coast and littoral, the dielectric infrared modelling of water material.
Cathala, Thierry; Latger, Jean
Helicopter support of North Sea oil exploration.
Exploration for oil beneath the North Sea started in the early 1960's with the discovery of natural gas and oil in the southern part between the coasts of East Anglia and the Netherlands. Since then oil exploration has built up considerably, the main effort moving northwards between the Shetland Islands and the Norwegian coasts. The helicopter offered the most direct and rapid contact with off-shore oil rigs and since these early days and immense helicopter operation has been built up round the borders of the North Sea by all the nations involved. Flying conditions in this area, particularly in winter, are at times difficult if not to say hazardous. Nevertheless, a sophisticated helicopter support service has been built up using modern aircraft and equipment which is unique in aviation history. This paper attempts to trace the history of the service, the operational problems involved and the special needs such as survival equipment and clothing. In addition, a co-ordinated air/sea rescue service largely based on helicopters has been built up and provides not only rescue facilities for possible rig disasters but also for shipping emergencies in the area. PMID:637822
Preston, F S
Probability of Sea Level Rise.
National Technical Information Service (NTIS)
The report develops probability-based projections that can be added to local tide-gage trends to estimate future sea level at particular locations. It uses the same models employed by previous assessments of sea level rise. The key coefficients in those m...
J. G. Titus V. K. Narayanan
The report develops probability-based projections that can be added to local tide-gage trends to estimate future sea level at particular locations. It uses the same models employed by previous assessments of sea level rise. The key coefficients in those models are based on subjective probability distributions supplied by a cross-section of climatologists, oceanographers, and glaciologists.
Titus, J.G.; Narayanan, V.K.
Palaeoclimate: The sea ice thickens
NASA Astrophysics Data System (ADS)
Little is known about the presence of high-latitude sea ice before 2.6 million years ago. A reanalysis of marine sediments from the Arctic Ocean indicates an intermittent presence of perennial sea ice as early as 44 million years ago.
Stickley, Catherine E.
Arctic Sea ice model sensitivities.
Arctic sea ice is an important component of the global climate system and, due to feedback effects, the Arctic ice cover is changing rapidly. Predictive mathematical models are of paramount importance for accurate estimates of the future ice trajectory. However, the sea ice components of Global Climate Models (GCMs) vary significantly in their prediction of the future state of Arctic sea ice and have generally underestimated the rate of decline in minimum sea ice extent seen over the past thirty years. One of the contributing factors to this variability is the sensitivity of the sea ice state to internal model parameters. A new sea ice model that holds some promise for improving sea ice predictions incorporates an anisotropic elastic-decohesive rheology and dynamics solved using the material-point method (MPM), which combines Lagrangian particles for advection with a background grid for gradient computations. We evaluate the variability of this MPM sea ice code and compare it with the Los Alamos National Laboratory CICE code for a single year simulation of the Arctic basin using consistent ocean and atmospheric forcing. Sensitivities of ice volume, ice area, ice extent, root mean square (RMS) ice speed, central Arctic ice thickness,and central Arctic ice speed with respect to ten different dynamic and thermodynamic parameters are evaluated both individually and in combination using the Design Analysis Kit for Optimization and Terascale Applications (DAKOTA). We find similar responses for the two codes and some interesting seasonal variability in the strength of the parameters on the solution.
Peterson, Kara J.; Bochev, Pavel Blagoveston; Paskaleva, Biliana Stefanova
National Technical Information Service (NTIS)
We are studying fully polarimetric scattering of electromagnetic waves from snow and sea ice with a three-layer random medium model which can account for snow covered sea ice. The snow layer is modeled as an isotropic random medium characterized by a scal...
J. A. Kong, R. T. Shin, M. Borgeaud, S. V. Nghiem
Country Analysis Briefs: Caspian Sea.
National Technical Information Service (NTIS)
The Caspian Sea region has become a central focal point for untapped oil and natural gas resources from the southern portion of the former Soviet Union. Beginning in May 2005, oil from the southern sections of the Caspian Sea began pumping through a new p...
NSDL National Science Digital Library
This NASA Astrobiology Institute article documents recent findings of bacterial life beneath the sea floor. These newly discovered bacteria are thought to live as far down as 500 meters beneath the sea floor and eat through volcanic rock, leaving behind burrows. The article contains hyperlinks to websites explaining some key vocabulary, related websites, and color photos and maps.
Mullen, Leslie; Institute, Nasa A.
Anatomy of Sea Turtles (Manual).
National Technical Information Service (NTIS)
The need for an up-to-date guide to the anatomy of sea turtles became clear toward the end of the 1900s. Increasing numbers of individuals developed the interest, talents, and techniques to study the biology of sea turtles, contend with their illnesses an...
J. Wyneken
NSDL National Science Digital Library
The Salton Sea is an accidental lake that receives used irrigation water from the Colorado River. Humans have profoundly altered the area's ecosystems. The sea is important for wildlife and recreation but is now saltier than the ocean. How might it be sav
Vessey, Kristin B.
National Technical Information Service (NTIS)
The seafloor has a profound role in Arctic sea ice formation and seasonal evolution. Ocean bathymetry controls the distribution and mixing of warm and cold waters, which may originate from different sources, thereby dictating the pattern of sea ice on the...
D. K. Hall G. Neumann I. G. Rigor P. Clemente-Colon S. V. Nghiem
Geophysics of sea ice in the Baltic Sea: A review
NASA Astrophysics Data System (ADS)
With improved observation methods, increased winter navigation, and increased awareness of the climate and environmental changes, research on the Baltic Sea ice conditions has become increasingly active. Sea ice has been recognized as a sensitive indicator for changes in climate. Although the inter-annual variability in the ice conditions is large, a change towards milder ice winters has been detected from the time series of the maximum annual extent of sea ice and the length of the ice season. On the basis of the ice extent, the shift towards a warmer climate took place in the latter half of the 19th century. On the other hand, data on the ice thickness, which are mostly limited to the land-fast ice zone, basically do not show clear trends during the 20th century, except that during the last 20 years the thickness of land-fast ice has decreased. Due to difficulties in measuring the pack-ice thickness, the total mass of sea ice in the Baltic Sea is, however, still poorly known. The ice extent and length of the ice season depend on the indices of the Arctic Oscillation and North Atlantic Oscillation. Sea ice dynamics, thermodynamics, structure, and properties strongly interact with each other, as well as with the atmosphere and the sea. The surface conditions over the ice-covered Baltic Sea show high spatial variability, which cannot be described by two surface types (such as ice and open water) only. The variability is strongly reflected to the radiative and turbulent surface fluxes. The Baltic Sea has served as a testbed for several developments in the theory of sea ice dynamics. Experiences with advanced models have increased our understanding on sea ice dynamics, which depends on the ice thickness distribution, and in turn redistributes the ice thickness. During the latest decade, advance has been made in studies on sea ice structure, surface albedo, penetration of solar radiation, sub-surface melting, and formation of superimposed ice and snow ice. A high vertical resolution has been found as a prerequisite to successfully model thermodynamic processes during the spring melt period. A few observations have demonstrated how the river discharge and ice melt affect the stratification of the oceanic boundary layer below the ice and the oceanic heat flux to the ice bottom. In general, process studies on ice-ocean interaction have been rare. In the future, increasingly multidisciplinary studies are needed with close links between sea ice physics, geochemistry and biology.
Vihma, Timo; Haapala, Jari
May organic pollutants affect fish populations in the North Sea?
The North Sea is a highly productive area with large fish populations that have been extensively harvested over the past century. North Sea fisheries remain important to the surrounding countries despite declining fish stocks over the past decades. The main reason for declining fish stocks is nearly certainly overfishing, but other environmental pressures also affect fish populations, such as eutrophication, climate change, and exposure to metals and organic pollutants, including polyaromatic hydrocarbons (PAHs), alkylphenols, and organochlorine compounds. There are three main sources of organic pollutants in the North Sea: atmospheric, land-based sources, and inputs from offshore gas and oil installations. All three sources contribute to elevated concentrations of organic pollutants in the North Sea compared to the Norwegian Sea. There is evidence that chlorinated organic contaminants were present in sufficiently high concentrations in the southern North Sea two decades ago, to alter embryonal development in fish. The results from extensive, long-term monitoring programs show that some diseases decreased whereas other increased in the southern North Sea and that, among other factors, contaminants may play a role in the temporal changes recorded in disease prevalence. Recent studies demonstrated that components in offshore effluents may affect fish reproduction and that tissues of fish near oil rigs are structurally different to tissues of fish from reference areas. Data on effluents from offshore activities have recently become available through an international workshop (BECPELAG) and follow-up studies. PMID:16291566
Hylland, Ketil; Beyer, Jonny; Berntssen, Marc; Klungsøyr, Jarle; Lang, Thomas; Balk, Lennart
Fishing effects in northeast Atlantic shelf seas: patterns in fishing effort, diversity and community structure. III. International trawling effort in the North Sea: an analysis of spatial and temporal trends
This paper describes trends in beam and otter trawling effort in the North Sea from 1977 to 1995. Data are presented as total hours fishing by English, German, Norwegian, Scottish and Welsh vessels for the period 1977–1995, and by Danish, Dutch, English, German, Norwegian, Scottish and Welsh vessels for the period 1990–1995. Analyses of temporal trends indicated that total international
S. Jennings; J. Alvsvag; A. J. R. Cotter; S. Ehrich; S. P. R. Greenstreet; A. Jarre-Teichmann; N. Mergardt; A. D. Rijnsdorp; O. Smedstad
NSDL National Science Digital Library
This lesson plan asks students to consider what happens when a sea shrinks and to compare pictures of the Aral Sea at different times. They will conclude by pretending to be residents of the Aral Sea region, drawing before and after pictures of how changes to the sea have affected their lives. Students will conduct an experiment to see whether salt evaporates with water; hypothesize what might happen to people, animals, and plants living near a shrinking sea; compare satellite images of the Aral Sea from 1973 and 1999; match problems in the Aral Sea region with statements about these problems in the Aral Sea family activity; discuss changes that are occurring in the Aral Sea region; and create drawings depicting the lives of people in the Aral Sea region before and after the sea began to shrink.
The Abyss of the Nordic Seas Is Warming
Over the past decade, the multiyear oceanographic time series from ocean weather station Mike at 66°N, 2°E indicate a warming by about 0.01°C yr1 in the deep water of the Norwegian Sea. The time of onset of this warming is depth dependent, starting at 2000-m depth in 1987 but not at the 1200-m level until 1990. The warming abruptly halts
Svein Østerhus; Tor Gammelsrød
NSDL National Science Digital Library
This site contains videos from the "Beneath the Sea" television episode, related website articles and student activities, and an interactive ocean game that tests knowledge of what creatures live at what depth. The videos feature technologies that have opened up the farthest reaches of the ocean and a remote submarine as it dives to the unexplored middle depths of the ocean off Monterey, California, revealing a spectacular variety of new life forms. The videos total approximately one hour in length. The articles explore how life survives in dark hot ocean vents and how this may shed light on the origin of life on Earth; evidence in support of the flood in the biblical story of Noah; and what deep-ocean research has revealed about continental drift, plate tectonics, and the formation of the Earth.
NSDL National Science Digital Library
This iOS app for the Illuminations online card game Deep Sea Duel (cataloged separately) helps users develop mental computation skills by finding sums of 3 or 4 numbers. A student and the opponent, Okta the octopus take turns selecting cards. The first one to reach the target sum with 3 cards (in the 9-card game) or 4 cards (in the 16-card game) wins the game. You can choose how many cards are presented (9 or 16), what types of numbers they display (small integers through tricky decimals), and Okta's level of strategy. The game is not timed but depends on strategic planning in order to defend against Okta's moves while trying to collect a winning group of cards.
NSDL National Science Digital Library
This Android app for the Illuminations online game Deep Sea Duel card game helps users develop mental computation skills by finding sums of 3 or 4 numbers. A student and the opponent, Okta the octopus take turns selecting cards. The first one to reach the target sum with 3 cards (in the 9-card game) or 4 cards (in the 16-card game) wins the game. You can choose how many cards are presented (9 or 16), what types of numbers they display (small integers through tricky decimals), and Okta's level of strategy. The game is not timed but depends on strategic planning in order to defend against Okta's moves while trying to collect a winning group of cards.
Polarimetric backscattering from sea ice
NASA Technical Reports Server (NTRS)
Polarimetric backscattering from sea ice is presented. Theoretical models for backscattering are first presented for various ice types. Then, theoretical results are compared with experimental data for new thin ice, first-year ice, and multi-year ice. Sea ice is modeled as a layer medium containing random scatterers and rough interfaces. For multi-year sea ice with snow cover, the sea ice layer is modeled as an ice background with embedded spheroidal air bubbles and the snow layer as air with ice grains. The hummocky topography on multi-year ice is characterized by a Gaussian distribution which has an averaging effect on backscattering coefficients. First-year sea ice is described by an ice medium hosting ellipsoidal brine inclusions. These inclusions are oriented preferentially in the vertical direction due to the columnar structure of first-year sea ice. Azimuthally, the orientation of the brine pockets are random corresponding to the random c-axes in sea ice, unless the axes are oriented by sea currents. For thin ice in newly opened leads, it has been observed that there exists a thin brine layer with very high salinity on the top surface of the new ice. This brine layer is depicted as a medium with high permittivity which can significantly affect electromagnetic scattering signatures from the lower thin ice layer, with a higher fractional volume of brine inclusions due to higher salinity as compared to thick first-year sea ice. The rough medium interfaces are described as Gaussian rough surfaces characterized by root-mean-square heights and surface correlation lengths. The contribution from rough surface, calculated under the Kirchhoff approximation or small perturbation method, is assumed to be independent from volume scattering. The total loss including absorption and scattering losses in the scattering media is represented by the imaginary part of effective permittivity obtained from the strong fluctuation theory. The polarimetric scattering coefficients for different ice types are then derived under the distorted Born approximation.
Nghiem, S. V.; Kwok, R.; Yueh, S. H.
NSDL National Science Digital Library
The Salton Sea is an "accidental" lake that receives used irrigation water from the Colorado River. Humans have profoundly altered the area's ecosystems. The Salton Sea is important for wildlife and recreation, but is now saltier than the ocean. How might it be saved? This case examines the Salton Sea's problems and uncertain future. The case would be suitable for introductory environmental, biology, geography and geology classes, and courses dealing with land use, water resources, agriculture, birds or fish, ecosystems, and government policy.
Vessey, Kristin B.
Iodine emissions from the sea ice of the Weddell Sea
NASA Astrophysics Data System (ADS)
Iodine compounds were measured above, below and within the sea ice of the Weddell Sea during a cruise in 2009, to elucidate the mechanism of local enhancement and volatilisation of iodine. I2 mixing ratios of up to 12.4 pptv were measured 10 m above the sea ice, and up to 31 pptv was observed above surface snow on the nearby Brunt Ice Shelf - large amounts. Atmospheric IO of up to 7 pptv was measured from the ship, and the average sum of HOI and ICl was 1.9 pptv. These measurements confirm the Weddell Sea as an iodine hotspot. Average atmospheric concentrations of CH3I, C2H5I, CH2ICl, 2-C3H7I, CH2IBr and 1-C3H7I were each 0.2 pptv or less. On the Brunt Ice Shelf, enhanced concentrations of CH3I and C2H5I (up to 0.5 and 1 pptv, respectively) were observed in firn air, with a diurnal profile that suggests the snow may be a source. In the sea ice brine, iodocarbons concentrations were over 10 times those of the sea water below. The sum of iodide + iodate was depleted in sea ice samples, suggesting some missing iodine chemistry. Flux calculations suggest I2 dominates the iodine atom flux to the atmosphere, but models cannot reconcile the observations and suggest either a missing iodine source or other deficiencies in our understanding of iodine chemistry. The observation of new particle formation, consistent with the model predictions, strongly suggests an iodine source. This combined study of iodine compounds is the first of its kind in this unique region of sea ice rich in biology and rich in iodine chemistry.
Atkinson, H. M.; Huang, R.-J.; Chance, R.; Roscoe, H. K.; Hughes, C.; Davison, B.; Schönhardt, A.; Mahajan, A. S.; Saiz-Lopez, A.; Hoffmann, T.; Liss, P. S.
Iodine emissions from the sea ice of the Weddell Sea
NASA Astrophysics Data System (ADS)
Iodine compounds were measured above, below and within the sea ice of the Weddell Sea during a cruise in 2009, to make progress in elucidating the mechanism of local enhancement and volatilisation of iodine. I2 mixing ratios of up to 12.4 pptv were measured 10 m above the sea ice, and up to 31 pptv was observed above surface snow on the nearby Brunt Ice Shelf - large amounts. Atmospheric IO of up to 7 pptv was measured from the ship, and the average sum of HOI and ICl was 1.9 pptv. These measurements confirm the Weddell Sea as an iodine hotspot. Average atmospheric concentrations of CH3I, C2H5I, CH2ICl, 2-C3H7I, CH2IBr and 1-C3H7I were each 0.2 pptv or less. On the Brunt Ice Shelf, enhanced concentrations of CH3I and C2H5I (up to 0.5 and 1 pptv respectively) were observed in firn air, with a diurnal profile that suggests the snow may be a source. In the sea ice brine, iodocarbons concentrations were over 10 times those of the sea water below. The sum of iodide + iodate was depleted in sea ice samples, suggesting some missing iodine chemistry. Flux calculations suggest I2 dominates the iodine atom flux to the atmosphere, but models cannot reconcile the observations and suggest either a missing iodine source or other deficiencies in our understanding of iodine chemistry. The observation of new particle formation, consistent with the model predictions, strongly suggests an iodine source. This combined study of iodine compounds is the first of its kind in this unique region of sea ice rich in biology and rich in iodine chemistry.
Atkinson, H. M.; Huang, R.-J.; Chance, R.; Roscoe, H. K.; Hughes, C.; Davison, B.; Schönhardt, A.; Mahajan, A. S.; Saiz-Lopez, A.; Hoffmann, T.; Liss, P. S.
Determination of reduced sensitivity in sea lice ( Lepeophtheirus salmonis Krøyer) against the pyrethroid deltamethrin using bioassays and probit modelling
Four Norwegian populations of the ectoparasitic copepod Lepeophtheirus salmonis K. were used to develop a bioassay for sensitivity determination to the pyrethroid deltamethrin (AlphaMax, Alpharma, Oslo, Norway, 10 mg deltamethrin ml?1). Bioassays using preadult II stage lice were performed with the sea lice exposed on salmon (Salmo salar L.) and with the sea lice exposed in polystyrene boxes. The purpose
Sigmund Sevatdal; Tor Einar Horsberg
Population structure of the deep-sea shrimp ( Pandalus borealis) in the north-east Atlantic based on allozyme variation
In order to elucidate the population structure of the deep-sea shrimp (Pandalus borealis) in the NE Atlantic, 32 subsamples and 3?865 individuals were analysed for allozymic variation. They were caught at various locations in the Barents Sea, in waters off Svalbard, Jan Mayen and Iceland, and in fjords along the Norwegian coast. Only three enzymes (malate dehydrogenase, phosphoglucomutase and glucosephosphate
Asbjørn Drengstig; Svein-Erik Fevolden; Pierre E. Galand; Michaela M. Aschan
Zooplankton data: Vertical distributions of zooplankton in the Norweigian and Greenland Seas during summer, 1989
Recent studies of zooplankton populations in the Greenland Sea have focused on processes at the Marginal Ice Zone (MIZ) and the areas immediately adjacent to it under the ice and in open water. These studies have shown a relatively short period of intense secondary productivity which is closely linked temporally and spatially to phytoplankton blooms occurring near the ice edge in spring and early summer. During the summer of 1989 we participated in a project focusing on benthic and water column processes in the basins of the Norwegian and Greenland Seas. This study allowed us to compare biological processes at the MIZ with those occurring in the open waters of the Greenland Sea, and to compare processes at both of these locations with those in the Norwegian Sea. The data presented in this report are the results of zooplankton net tows covering the upper 1000 meters of the water column over the Norwegian Sea basin and the Greenland Sea basin, and the upper 500 meters of open water adjacent to the MIZ in the Greenland Sea. Sampling was conducted between 12 and 29 July 1989.
Lane, P.V.Z.; Smith, S.L.; Schwarting, E.M.
Regional variability of sea level trends
Satellite altimetry has allowed precise mapping of the geographical variability of the rates of sea level change and showed that sea level is far from rising uniformely. In some regions, rates are up several times the global mean rise, while in other regions sea level is falling. Like observed sea level trends, observed and model-based ocean thermal expansion trends are
A. Cazenave; A. Lombard; W. Llovel; R. Abarca Del Rio
National Technical Information Service (NTIS)
Following introductory remarks by S. W. Wurfel are the following studies: The United States Draft Seabed Convention--background, interests represented, and prospects for agreement; The Stockholm Conference--some implications for the law of the sea; Develo...
S. W. Wurfel
NSDL National Science Digital Library
This interactive tool helps students grasp the difficult task of locating deep sea vents. By allowing them to virtually survey a portion of the Juan de Fuca Ridge in the Pacific Ocean, they get to experience the process firsthand.
NSDL National Science Digital Library
This student-friendly list has eight web sites that relate to deep sea vents. A short description follows each site, listing the reference materials, interactive tools, videos, sound recordings, photo archives, or other resources that can be found there.
After an unusually cold summer in the northernmost latitudes, Arctic sea ice appears to have reached its annual minimum summer extent for 2013 on Sept. 13, the NASA-supported National Snow and Ice ...
Doppler characteristics of sea clutter.
Doppler radars can distinguish targets from clutter if the target's velocity along the radar line of sight is beyond that of the clutter. Some targets of interest may have a Doppler shift similar to that of clutter. The nature of sea clutter is different in the clutter and exo-clutter regions. This behavior requires special consideration regarding where a radar can expect to find sea-clutter returns in Doppler space and what detection algorithms are most appropriate to help mitigate false alarms and increase probability of detection of a target. This paper studies the existing state-of-the-art in the understanding of Doppler characteristics of sea clutter and scattering from the ocean to better understand the design and performance choices of a radar in differentiating targets from clutter under prevailing sea conditions.
Raynal, Ann Marie; Doerry, Armin Walter
NSDL National Science Digital Library
Students learn that navigational techniques change when people travel to different places â land, sea, air and space. For example, an explorer traveling by land uses different navigation methods and tools than a sailor or an astronaut.
Integrated Teaching And Learning Program
NSDL National Science Digital Library
This video adapted from Texas Parks and Wildlife Department describes how humans are helping restore safe nesting grounds for the critically endangered Kemp's ridley sea turtle to ensure its successful repopulation.
Foundation, Wgbh E.
Arctic Sea Ice Satellite Observations
NSDL National Science Digital Library
In this interactive activity produced for Teachers' Domain, learn how Arctic sea ice has changed over the past 25 years in terms of maximum winter extent, concentration, and the timing of breakup each spring.
Foundation, Wgbh E.
Introduction to Sea Island Folklife.
ERIC Educational Resources Information Center
Examines the economic activity, language, world view, kinship patterns, and religion of contemporary Sea Islanders in order to illustrate the Islands' cultural conservatism and, thus, their appropriateness for the study of Africanism in the United States. (GC)
Twining, Mary A.; Baird, Keith E.
NASA Astrophysics Data System (ADS)
A feasibility study was made for a salt gradient solar pond power plant in or near the Salton Sea of California. The conclusions support continuance 5-MWe proof-of-concept experiment, and ultimate construction by an electric utility company of a 600-MWe plant. The Solar Pond concept would be an environmental benefit to the Salton Sea by reversing the increasing salinity trend. The greatest cost drivers are the lake dike construction and pond sealing. Problems to be resolved include method of brine production from Salton Sea water for the first unit (which requires evaporation pond area and time), the high turbidity and color content of the Salton Sea water (which requires pretreatment), and other questions related to pond permeability, bio-activity and soil/brine chemical reactions. All technical and environmental problems appear solvable and/or manageable if care is taken in mitigating impacts.
Peelgren, M. L.
ERIC Educational Resources Information Center
A comprehensive discussion of the free-living worms that inhabit the beaches and subtidal bottoms of the Cape Cod shoreline is presented. Methods for the location, collection, preservation, and identification of sea worms are identified. (BT)
Zinn, Donald J.
Yellow Sea Shallow Water Experiment.
National Technical Information Service (NTIS)
The purpose of this grant is to support the acquisition of both oceanographic and acoustic measurements to assesss reverberation and the backscatter from the sea bottom and surface, propagation loss, and the effects of internal wave soutons on acoustic mo...
G. W. Caille P. H. Rogers
Modern processes controlling the sea bed sediment formation in Barents Sea
NASA Astrophysics Data System (ADS)
The Barents Sea is one of the key regions for understanding of the postglacial history of the climate and circulation of the World Ocean. There are the limits of warm North Atlantic waters penetration to the Arctic and a zone of interaction between Atlantic and Arctic waters. The Barents Se's limits are the deep Norwegian Sea in the West, the Spitsbergen Island and the Franz Josef Land and the deep Nansen trough in the North, the Novaya Zemlya archipelago in the East and the North shore of Europe in the South. An analysis of Eurasian-Arctic continental margin shows correspondence between the rift systems of the shelf with those of the ocean. This relation can be observed in the central Arctic region. All the rift systems underlying the sediment basin are expressed in the sea bed relief as spacious and extensive graben valleys burnished by lobes. Two transverse trenches cross both shelf and continental slope, namely the Medvezhinsky trench between Norway and Spitsbergen in the West and the Franz Victoria trench between Spitsbergen and the Franz Josef Land in the North. The Barents and the Kara Seas are connected by the Kara Gate Strait and wide transverse trough of Saint Anna in the North-West. The recent assessment of the eolian solid sediment supply to the Barents Sea is about 0.904 tons. The Barents Sea as a whole should be considered as "starving" in terms of its feeding with solid sediment matter. Observations show the considerable part of the sea bottom to be free of Holocene sediment cover. The more ancient Quaternary units or bedrock can be seen at the bottom surface. This phenomenon is the most typical for arches of relatively shallow elevations. Thick accumulations of new sediments are connected with fjords. The amount of sea ice delivered from the Barents Sea to the Arctic Ocean is 35 km3 a year. This value should be added by iceberg delivery from the North island of Novaya Zemlya, the Franz Josef Land, the Spitsbergen Island and North Norway but most of terrigenous matter settles in natural sediment traps of fjords. The Barents Sea bottom has rather dissected relief. A number of isometric or, rarer, elongated underwater elevations (Perseus, Central, the Admiralty Bar, the Goose shoal) and separation trenches and troughs (South and North Barents Sea troughs, Perseus, Aldanov, Medvezhinsky, Franz Victoria, West and South Novozemelsky trenches) can be distinguished. The major processes that control a structure of the friable sedimentary cover of Arctic shelves appear on the seismic acoustic records as chaotic effect of cryolithogenesis (permafrost, themokarst, thawed patches, paleoriverbeds, etc.) and hydrocarbons migration (gas hydrates, gas saturated sediments, gas seeping, porkmarks, etc). Such phenomena are the main components of geo-risks for oil and gas fields development in Arctic Seas and are, together with the gas hydrates deposits, the top priority objects of seismic acoustic measurements. The shelf of the Barents Sea is one of the most extensively studied with high resolution acoustic methods because of large-scale engineering and geological problems solved in process of its industrial development. Mainly, it is related to exploring and development of oil and gas fields, oil terminals and submarine pipelines construction, and building up the whole infrastructure for their exploitation.
Balanyuk, I.; Dmitrievsky, A.; Shapovalov, S.; Chaikina, O.; Akivis, T.
NSDL National Science Digital Library
In this lesson students investigate bathymetric mapping of deep-sea habitats to see how deep-sea areas of the northwestern Hawaiian Islands can be mapped to facilitate their exploration with a manned submersible. Students will create a two-dimensional topographic map from bathymetric survey data, a three-dimensional model of landforms from a two-dimensional topographic map, and will interpret two- and three-dimensional topographic data.
Goodwin, Mel
Earthwatch Radio: Sea Lamprey Resurgence
NSDL National Science Digital Library
This radio broadcast describes efforts to control the population of sea lampreys in the Great Lakes. Sea lampreys, an invasive species from the Atlantic Ocean, have populated the lakes for years, but have recently increased in numbers despite efforts to control them. A hole in a dam on the Manistique River on the northern edge of Lake Michigan is thought to have caused the problem. The clip is 2 minutes in length and may be downloaded in MP3 format.
Kalinowski, Laura
NSDL National Science Digital Library
The SeaWIFS project uses space technology to study phytoplankton. Site contains: The Living Ocean Teacher's Guide, a guide for grades 9-10 that discusses satellites, ocean color, phytoplankton, the carbon cycle, and greenhouse effect; Classic CZCS Scenes, a tutorial about ocean color using some of the more interesting CZCS images; and Monitoring the Earth from Space with SeaWiFS, an presentation about ocean color; and several other remote sensing resources.
Sea Turtle First Aid Investigation
NSDL National Science Digital Library
This activity (located on page 4 of the PDF) is a full inquiry investigation into testing a repair material. Groups of learners perform âfirst aidâ on a cut orange, which represents propeller damage on the back of a leatherback sea turtle. Learners use a variety of repair materials and predict how well various treatments will work, then observe treated, untreated, and uncut control oranges for 4 days. Relates to linked video, DragonflyTV GPS: Sea Turtles.
Twin Cities Public Television, Inc.
DESERVE - Dead Sea Research Venue
NASA Astrophysics Data System (ADS)
DESERVE 'Dead Sea Research Venue' focuses on the Dead Sea region as it is a unique environment and may be considered as one of the most inspiring natural laboratories on Earth. The Dead Sea Region is an exceptional ecosystem whose seismic activity has influenced all facets of the development, from ground water availability to human evolution. DESERVE addresses three grand challenges: Environmental Risks, Water Availability, Climate Change and comprises long term monitoring of geophysical parameters, studies of coupled processes in the atmosphere, hydrosphere and lithosphere as well as modeling of prediction and remediation strategies of geogenic risks. The Dead Sea has been selected for this integrated approach because it constitutes an outstanding 'natural laboratory' to study these phenomena, as - all 3 challenges are critical in this region. - the region is especially sensitive to climate change and human influences such as ground and surface water over-exploitation for agriculture and industrial purposes. - environmental processes are subject to boundary conditions that cannot be found elsewhere on Earth - understanding their interactions and the future evolution of the whole Dead Sea region are of key importance for economic development in peaceful cooperation. Results obtained in the Dead Sea region are also of prototype relevance for other (semi)-arid terminal basins of the world.
Mohsen, A.; Weber, M. H.; Kottmeier, C.
Intermittent sea-level acceleration
NASA Astrophysics Data System (ADS)
Using instrumental observations from the Permanent Service for Mean Sea Level (PSMSL), we provide a new assessment of the global sea-level acceleration for the last ~ 2 centuries (1820-2010). Our results, obtained by a stack of tide gauge time series, confirm the existence of a global sea-level acceleration (GSLA) and, coherently with independent assessments so far, they point to a value close to 0.01 mm/yr2. However, differently from previous studies, we discuss how change points or abrupt inflections in individual sea-level time series have contributed to the GSLA. Our analysis, based on methods borrowed from econometrics, suggests the existence of two distinct driving mechanisms for the GSLA, both involving a minority of tide gauges globally. The first effectively implies a gradual increase in the rate of sea-level rise at individual tide gauges, while the second is manifest through a sequence of catastrophic variations of the sea-level trend. These occurred intermittently since the end of the 19th century and became more frequent during the last four decades.
Olivieri, M.; Spada, G.
Many of the early North Sea platforms are reaching their end-of-field life. Most are still equipped with their original drilling package. In a few cases the package has either been removed or decommissioned. The early installations were designed for much simpler and less demanding wells than the horizontal, extended-reach or designer wells common today. Extended-reach wells now can be drilled realistically from ageing platforms, without incurring massive capital expenditure. This can be achieved using the existing drilling package to the limit of its capabilities and supplementing where necessary with relatively minor upgrades or the use of temporary equipment. Drilling even a few more wells from existing platforms not only prolongs field life, it enables any surplus processing capacity to be made available to develop near-field potential with extended-reach drilling (ERD) or by tying back subsea satellite wells, or for processing third-party fluids. The paper describes well design, surface equipment, mud pumps, shakers and solids control equipment, drill cuttings disposal systems, derrick and hoisting system, top drive and drillstring, downhole equipment, well planning, casing wear, logistics, rig preparations, and ERD vs. subsea tie-backs.
O'Hare, J.
NASA Astrophysics Data System (ADS)
In the late 1960s oil and gas development became an issue in the northern coastal areas of Alaska and Canada. More lately this has also become an issue in the Euroasian Arctic with the Barents and Kara Seas as example on where offshore hydrocarbon production now is being planned. In such waters the key questions prior to a development are related to water depths at the site and in case of ice, how frequent and what type of ice features will be met. Especially the ice conditions and knowledge about them are very decisive for the field development solutions to be chosen. The paper will highlight examples on development solutions where the ice conditions have played a paramount role in the field development plans. An example is the consequences of iceberg threaten in an area and the effect sudden changes in ice drift directions may have on the exploration and drilling solutions chosen. The paper will also discuss how to derive design ice actions values for such waters including scaling from nature to model ice basins.
Løset, S.
50 CFR 648.11 - At-sea sea sampler/observer coverage.
Code of Federal Regulations, 2013 CFR
...mackerel, squid, butterfish, scup, black sea bass, bluefish, spiny dogfish...permit, a scup moratorium permit, a black sea bass moratorium permit, a bluefish...mammals, summer flounder, scup, black sea bass, bluefish, spiny...
Influence of oceanic heat variability on sea ice anomalies in the Nordic Seas
NASA Astrophysics Data System (ADS)
A strong control of sea ice area (SIA) in the Nordic Seas in the period 1982-2006 by oceanic heat variability is reported. In particular, variability of summer Atlantic water temperature in the Barents Sea Opening explains about 75% of the variance of the following winter SIA anomalies which opens prospects for seasonal predictability of regional sea ice cover. A strong link of winter SIA anomalies to variability in the previous spring sea surface temperature on the western (Greenland Sea) and eastern (Barents Sea) sides of the Nordic Seas indicates that the oceanic control of sea ice cover in these areas mainly results from postsummer surface reemergence of oceanic heat anomalies generated by earlier atmospheric forcing. In particular, late winter North Atlantic Oscillation and anomalous winds across the Barents Sea ice edge significantly influence next winter sea ice cover on the western and eastern sides of the Nordic Seas, respectively.
Schlichtholz, P.
Brief: Offshore North Sea case histories of the environmentally friendly testing vessel, the Crystal Sea
One problem during offshore well-test operations, stimulations, and routine workovers are discharges into the air and sea while flaring. These procedures are usually performed by mobile drilling rigs with no storage capacity, and thus, hydrocarbons sequestered must be burned off from the rig flare booms. Another major problem has been the inability of the flare to operate at high flow rates. Because the burning process slows the pace of a test, restricting full flow testing, valuable well information is lost. Flaring of hydrocarbons also represents an economic loss. In the case of oil rigs, for example, flaring not only emits CO{sub 2} into the atmosphere but also burns off usable oil. The Crystal Sea well-test vessel was designed to address the problems inherent to flaring and, at the same time, provide cost efficiency by salvaging usable oil during well testing. The success of her initial two jobs on the Statfjord North satellite field in the Norwegian sector of the North Sea confirms that sale of the salvaged oil normally lost during the flaring process could generate sufficient economic return to pay for the vessel. In addition, with its capability to receive products at twice the flow rate of conventional methods, the increased accuracy of the technical information obtained from the well test further enhances its value for improved reservoir management.
Tjelta, O.; Ashwell, C.; Hilmarsen, G.; Taylor, R.W.
Deep-sea Hexactinellida (Porifera) of the Weddell Sea
NASA Astrophysics Data System (ADS)
New Hexactinellida from the deep Weddel Sea are described. This moderately diverse hexactinellid fauna includes 14 species belonging to 12 genera, of which five species and one subgenus are new to science: Periphragella antarctica n. sp., Holascus pseudostellatus n. sp., Caulophacus (Caulophacus) discohexactinus n. sp., C. ( Caulodiscus) brandti n. sp., C. ( Oxydiscus) weddelli n. sp., and C. ( Oxydiscus) n. subgen. So far, 20 hexactinellid species have been reported from the deep Weddell Sea, 15 are known from the northern part and 10 only from here, while 10 came from the southern area, and five of these only from there. However, this apparent high "endemism" of Antarctic hexactinellid sponges is most likely the result of severe undersampling of the deep-sea fauna. We find no reason to believe that a division between an oceanic and a more continental group of species exists. The current poor database indicates that a substantial part of the deep hexactinellid fauna of the Weddell Sea is shared with other deep-sea regions, but it does not indicate a special biogeographic relationship with any other ocean.
Janussen, Dorte; Tabachnick, Konstantin R.; Tendal, Ole S.
Sea ice drift tracking in the Bohai Sea based on optical flow
NASA Astrophysics Data System (ADS)
In the Bohai Sea, sea ice drifting is hardly tracked due to the highly sea motion. The long satellite repeat cycles in the polar region are not suitable to the ice drift tracking in the Bohai Sea. The unique characteristics of the Geostationary Ocean Color Imager (GOCI) allow the tracking of sea ice drift on a daily basis with the use of 1-hour time intervals images (eight images per day). The optical flow method is applied to track the sea ice drift in the Bohai Sea. Experiments have shown that the sea ice vectors from the optical flow method are agreement well with the manually selected reference data.
Wu, Qing; Lang, Wenhui; Zhang, Xi; Yang, Xuezhi
Magnetohydrodynamic sea water propulsion
An experimental and theoretical investigation of a large scale MHD propulsor has been undertaken whose objectives are to (1) investigate the transient and steady state performance of the thruster over operating parameter ranges that are compatible with achievement of high efficiency, (2) to quantify the principal loss mechanisms within the thruster and (3) to obtain preliminary hydroacoustic data. The performance of the thruster was first investigated theoretically with a 3-D code to quantify the loss mechanisms and identify experimental parameter ranges of interest. The loss mechanisms of interest are ohmic losses within the channel and those resulting from electrical currents at the entrance and exit of the thruster, and enhanced frictional losses. The analysis indicated that the relative importance of the loss mechanisms was a function of the thruster design and operating parameters. The experimental investigation of the large scale propulsor is being conducted on a sea water test facility that was designed to match the capabilities of a large 6-T superconducting magnet. The facility design was such that {approximately}90{degrees} of all losses occurred within the propulsion test train (inlet nozzle, propulsor and diffuser) thus facilitating isolation of the loss mechanisms. The test thruster itself is heavily instrumented to provide local measurements of velocity, pressure, and electric fields. The predicted overall thruster performance and value of the loss mechanisms will be compared with measured values. Comparisons will also be presented of the voltage gradients between electrodes, overall thruster efficiency, axial pressure gradients across the propulsor, change in velocity profiles, axial and vertical current distributions and exit distribution of the electrolytic gases.
Petrick, M.; Thomas, A.; Genens, L.; Libera, J.; Nietert, R.; Bouillard, J.; Pierson, E.; Hill, D.; Picologlou, B.; Ohlsson, O.; Kasprzyk, T.; Berry, G.
Magnetohydrodynamic sea water propulsion
An experimental and theoretical investigation of a large scale MHD propulsor has been undertaken whose objectives are to (1) investigate the transient and steady state performance of the thruster over operating parameter ranges that are compatible with achievement of high efficiency, (2) to quantify the principal loss mechanisms within the thruster and (3) to obtain preliminary hydroacoustic data. The performance of the thruster was first investigated theoretically with a 3-D code to quantify the loss mechanisms and identify experimental parameter ranges of interest. The loss mechanisms of interest are ohmic losses within the channel and those resulting from electrical currents at the entrance and exit of the thruster, and enhanced frictional losses. The analysis indicated that the relative importance of the loss mechanisms was a function of the thruster design and operating parameters. The experimental investigation of the large scale propulsor is being conducted on a sea water test facility that was designed to match the capabilities of a large 6-T superconducting magnet. The facility design was such that {approximately}90{degrees} of all losses occurred within the propulsion test train (inlet nozzle, propulsor and diffuser) thus facilitating isolation of the loss mechanisms. The test thruster itself is heavily instrumented to provide local measurements of velocity, pressure, and electric fields. The predicted overall thruster performance and value of the loss mechanisms will be compared with measured values. Comparisons will also be presented of the voltage gradients between electrodes, overall thruster efficiency, axial pressure gradients across the propulsor, change in velocity profiles, axial and vertical current distributions and exit distribution of the electrolytic gases.
Petrick, M.; Thomas, A.; Genens, L.; Libera, J.; Nietert, R.; Bouillard, J.; Pierson, E.; Hill, D.; Picologlou, B.; Ohlsson, O.; Kasprzyk, T.; Berry, G.
NASA Technical Reports Server (NTRS)The frequent coverage provided by NASA's SeaWinds instrument on the QuikScat satellite provides unprecedented capability to monitor daily and seasonal changes in the key melt zones of Greenland, which is covered with a thick ice sheet that resulted from snow accumulating over tens of thousands of years. The thickness of the snow layers reveals details about the past global climate, and comparing snow accumulation and snow melting can provide insight into climate change and global warming. In particular, the extent of summer melting of snow in Greenland is considered a sensitive indicator of global change.Earlier scatterometer data has suggested that Greenland has experienced significantly more melting in recent years. This figure compares the melting observed over 15 days during July 1999 in Greenland. The red areas around the central blue and white areas are the main melt zones and have lower radar back scatter because of water on the surface that saturates the surface snow. As the days warm up, the melt extent dramatically increases. Comparing this data with computer models and past scatterometer data will help scientists evaluate the inter-annual variability of the melting as a step toward understanding potential climate change.The world's large ice sheets in Greenland and Antarctica act as vast storehouses of freshwater. Summer season melting releases large quantities of freshwater into the ocean, and year-to-year variations can have a significant impact on global sea level. Furthermore, long-term changes in the patterns and extent of melting on the large ice sheets reflect the effects of climate variability; thus Greenland is considered a sensitive indicator of global warming.Satellite microwave radars are extremely sensitive to melting and can provide the only effective means of accurately measuring the year-round picture of the extent and variability in ice sheet melting. Daily mean images were produced from QuikScat data collected over the Greenland ice sheet at the height of the present summer melt period. In the top row, four images are shown at intervals of 5 days, for (a) day 203, (b) 208,(c) 213, and (d) 218 in 1999. Blue and white colors indicate surfaces which are cold and dry, while read and black indicate wet snow surfaces experiencing melting. The coastal regions are lower in elevation and begin to melt first. As summer progresses, the area of melting expands inland and northwards along the western coast of Greenland as air temperatures warm. A large pale and dark blue region in the central, high-elevation part of the ice sheet survives each summer without experiencing any melting. This is known as the dry snow region, and its area is a measure of the stability of the central part of the ice sheet. The line dividing the melt area and the dry snow is very sensitive to climate conditions and monitoring this line will help scientists determine whether the Earth's climate is changing.The lower series of four images shows the daily variability in the radar data within each image. White patches in these images identify regions where the most rapid changes are taking place. Air temperature and precipitation variations are responsible for the patterns, with the greatest impact over the southern tip of Greenland occurring from storms originating over the Atlantic. Note that the red areas of central and northern Greenland experience much smaller or slower changes, with the central ice sheet showing little change during this summer period.With its frequent coverage, the SeaWinds instrument is a power and unique tool for monitoring the health of the large ice sheets. The continuing time-series of data is a valuable contribution to assessments of the effects and impact of global change in the polar regions.NASA's Earth Science Enterprise is a long-term research and technology program designed to examine Earth's land, oceans, atmosphere, ice and life as a total integrated system. JPL is a division of the California Institute of Technology, Pasadena
Ground-Truthing 11- to 12kHz side-scan sonar imagery in the Norwegian–Greenland Sea: Part II: Probable diapirs on the Bear Island fan slide valley margins and the Vøring Plateau
SeaMARC II (11- to 12-kHz) side-scan sonar revealed hundreds of small strong-backscatter spots, tens to 500?m in diameter,\\u000a along the lips of the Bear Island fan slide valley. New bathymetry, deep-tow side-scan, deep-tow profiles, heatflow, and gravity\\u000a cores were collected for ground-truth. These mounds are probably mud diapirs (or mud-built mounds) typically 10–75?m high,\\u000a formed by glacial sediment mobilized by
P. R. Vogt; K. Crane; E. Sundvor; B. O. Hjelstuen; J. Gardner; F. Bowles; G. Cherkashev
Satellite observations of sea surface temperature and sea surface wind coupling in the Japan Sea
NASA Astrophysics Data System (ADS)
We investigate ocean-atmosphere coupling in the Japan Sea by using microwave satellite measurements of sea surface temperature (SST) and sea surface wind from 1 June 2002 to 31 December 2004. First, it is observed that instantaneous wind speeds are modified by SST front meanders in widespread areas in the Japan Sea. Increased/reduced wind speeds are found over warmer/colder water. Then, we compute SST and wind speed anomalies by spatial high-pass filtering in order to present their time evolution along 132°E. SST and wind speed anomalies are negatively correlated off Vladivostok (>41°N) in winter. This is consistent with the interpretation that there is large turbulent heat flux loss due to the wind speed maximum off Vladivostok or the gap exit region of the northwesterly wind jet. However, except for this region in winter, we find strong positive correlation between SST and wind speed anomalies throughout the year at any latitudes. Wind speed anomalies are linearly related to SST anomalies. Meanwhile, we identify two pairs of positive and negative SST anomaly bands in the time-space structure of the Japan Sea and compare the band locations with meridional SST gradient magnitude. As a result, the two boundaries of the SST anomaly bands are associated with the Polar Front and the Tsushima Warm Current front. Additionally, it is found that discontinuous SST anomaly patches correspond to oceanic eddies. These results lead to the conclusion that sea surface winds over the Japan Sea come under the influence of those SST frontal systems.
Shimada, Teruhisa; Kawamura, Hiroshi
Effects of sea spray geoengineering
NASA Astrophysics Data System (ADS)
Anthropogenic climate warming is leading to consideration of options for geoengineering to offset rising carbon dioxide levels. One potential technique involves injecting artificial sea spray into the atmosphere. The sea salt particles would affect Earth's radiation budget directly, by scattering incoming solar radiation, and indirectly, by acting as cloud condensation nuclei, which could lead to whiter clouds that reflect more radiation. However, the potential effects of this method, especially the direct effects, are not fully known. Partanen et al. studied the effects of artificial sea spray using climate model simulations. They found that outside of the most heavily clouded regions the direct effect of scattering of radiation was an important part of the total effect. They also examined the effect of particle size and found that decreasing the size of injected particles could improve the efficiency of the geoengineering technique.
Balcerak, Ernie
ConcepTest: Effect of Rain on Sea Level
NSDL National Science Digital Library
A majority of Earth's water is in the oceans. Predict what would happen to sea level if rain fell continuously all over the world's oceans. a. Sea level would rise b. Sea level would fall c. Sea level ...
Factors controlling ebro deep-sea fan growth, Mediterranean Sea
Tectonic, sediment-source and sea-level factors control depositional patterns of the Ebro deep-sea fan system. In unstable, steep continental slope terrain, mass movement of material results in wide gullied canyons and formation of non-channelized debris aprons. These fan channels develop low sinuosity and generally traverse the continental rise without feeding into depositional lobes because of steep gradients (1:50 to 1:100) and sediment draining into the subsiding Valencia Valley graben. An abundance of sediment input points from mass failure and many river-fed canyons contributes to a depositional pattern of side-by-side debris aprons and separate channel-levee complexes. When a large sediment supply feeds a channel for a relatively long period 1) fan valley sinuosity increases: 2) channel walls are modified through undercutting, slumping, and crevasse splays: 3) channel bifurcation occurs: 4) incipient depositional lobe formation begins. Lowering of sea levels in Late Pleistocene time permitted the access of coarse river sediment to slope valleys and promoted deposition of numerous turbidites and active growth of the fan. During the Holocene, when sea levels have been high, a regime of hemipelagic sedimentation, mass movement, and debris apron sedimentation has dominated.
Nelson, C.H.; Maldonado, A.; Alonso, B.; Palanques, A.; Ryan, W.B.F.; Kastens, K.; O'Connel, S.
Teleconnections and Sea Ice Variability in the Greenland Sea.
National Technical Information Service (NTIS)
The purpose of this study is to examine and test the hypothesis that the multiyear sea ice variability in the East Greenland Current is related to the El Nino/Southern Oscillation phenomenon and/or the North Atlantic Oscillation via atmospheric teleconnec...
W. A. Wilson
SeaWorld Snack Shop - SeaWorld Classroom Activity
NSDL National Science Digital Library
In this problem-solving activity, challenges students to take on the role of a Food Services Manager placing orders for a snack shop at Sea World. To solve the problem they will use data and proportional reasoning to make predictions and communicate findings.
Teachers, Sea W.
Future sea-level rise in the Mediterranean Sea
NASA Astrophysics Data System (ADS)
Secular sea level variations in the Mediterranean Sea are the result of a number of processes characterized by distinct time scales and spatial patterns. Here we predict the future sea level variations in the Mediterranean Sea to year 2050 combining the contributions from terrestrial ice melt (TIM), glacial isostatic adjustment (GIA), and the ocean response (OR) that includes the thermal expansion and the ocean circulation contributions. The three contributions are characterized by comparable magnitudes but distinctly different sea-level fingerprints across the Mediterranean basin. The TIM component of future sea-level rise is taken from Spada et al. (2013) and it is mainly driven by the melt of small glaciers and ice caps and by the dynamic ice loss from Antarctica. The sea-level fingerprint associated with GIA is studied using two distinct models available from the literature: ICE-5G(VM2) (Peltier, 2004) and the ice model progressively developed at the Research School of Earth Sciences (RSES) of the National Australian University (KL05) (see Fleming and Lambeck, 2004 and references therein). Both the GIA and the TIM sea-level predictions have been obtained with the aid of the SELEN program (Spada and Stocchi, 2007). The spatially-averaged OR component, which includes thermosteric and halosteric sea-level variations, recently obtained using a regional coupled ocean-atmosphere model (Carillo et al., 2012), vary between 2 and 7 cm according to scenarios adopted (EA1B and EA1B2, see Meehl at al., 2007). Since the sea-level variations associated with TIM mainly result from the gravitational interactions between the cryosphere components, the oceans and the solid Earth, and long-wavelength rotational variations, they are characterized by a very smooth global pattern and by a marked zonal symmetry reflecting the dipole geometry of the ice sources. Since the Mediterranean Sea is located in the intermediate far-field of major ice sources, TIM sea-level changes have sub-eustatic values (i.e. they do not exceed the global average) and show little (but still significant) variations across the basin associated with the subsidence driven by the meltwater load. For year 2050, TIM calculations predict a sea-level rise of ~10 and ~30 cm for the mid range and the high end scenarios, respectively. Mainly because of the distinct mantle viscosity profiles adopted in ICE-5G(VM2) and KL05, the GIA patterns differ significantly and, in contrast with the TIM fingerprint, are both characterized by strong variations across the Mediterranean Sea, showing maximum values in the bulk of the basin. For the OR component, a significant geographical variation is observed across the Mediterranean sub-basins, corresponding to different Atlantic boundary conditionsAccording to this study, the total future sea-level rise for year 2050 will reach maximum values for the extreme scenario (hig-hend prediction for TIM, KL05 for GIA and EA1B2 for OR) of ˜ 27 cm in average with peak of ˜ 30 cm in the central sub-basins. Our results show that when these three components of future sea-level rise are simultaneously considered, the spatial variability is enhanced because of the neatly distinct geometry of the three fingerprints. References: Carillo, A., Sannino, G., Artale, V., Ruti, P., Calmanti, S., DellAquila, A., 2012, Clim. Dyn. 39 (9-10), 2167-2184; Fleming, K. and Lambeck, K., 2004, Quat. Sci. Rev. 23 (9-10), 1053-1077; Meehl, G.A., and 11 others, 2007, in Climate Change 2007: The Physical Science Basis, Cambridge University Press; Peltier W.R., 2004, Annu. Rev. Earth Pl. Sc., 32, 111-149; Spada, G. and Stocchi, P., 2007, Comput. and Geosci., 33(4), 538-562; Spada G., Bamber J. L., Hurkmans R. T. W. L., 2013, Geophys. Res. Lett., 1-5, 40.
Galassi, Gaia; Spada, Giorgio
A sea otter pup watches eagerly as its mother eats a fat innkeeper worm in Monterey Bay, California. USGS scientists study sea otters in efforts to help the threatened species continue to recover from near extinction....
Origin of the Crimea and Black Sea.
National Technical Information Service (NTIS)
It is generally assumed that the Crimean mountains represent the remnants of a large mountain structure-anticlinorium, similar to the Caucasus Mountains, destroyed during the formation of the Black Sea basin. Many geologists considered the Black Sea to be...
S. A. Kovalevskii
Measuring the Composition of a Cryogenic Sea
NASA Astrophysics Data System (ADS)
Titan seas are prime science targets, but compositional measurements require robust sampling techniques. We will discuss the challenges and successful developments towards cryogenic fluid sampling and mass spectrometric measurement of Titan seas.
Trainer, M. G.; Mahaffy, P. R.; Stofan, E. R.; Lunine, J. I.; Lorenz, R. D.
Lysosomes and Intracellular Digestion in Sea Stars.
National Technical Information Service (NTIS)
The study of lysosomes and intracellular digestion in sea stars seemed ideal. Echinoderms occupy an intermediate position in the phylogenetic progression from protozoan to mammal. A single sea star can cleanly provide a large amount of relatively homogeno...
G. S. Araki
Antarctic sea ice mapping using the AVHRR
A sea ice mapping scheme based on Advanced Very High Resolution Radiometer (AVHRR) data from the National Oceanic and Atmospheric Administration (NOAA) polar orbiting satellites has been developed and applied to daylight images taken between November 1989 to January 1990 and November 1990 to January 1991 over the Weddell and the Ross Seas. After masking the continent and ice shelves, sea ice is discriminated from clouds and open sea using thresholds applied to the multidimensional space formed by AVHRR Channel 2, 3, and 4 radiances. Sea ice concentrations in cloud-free regions are then computed using the tie-point method. Results based on the analysis of more than 70 images show that the proposed scheme is capable of properly discriminating between sea ice, open sea, and clouds, under most conditions, thus allowing high resolution sea ice maps to be produced during the austral summer season.
Zibordi, G. (Inst. for the Study of Geophysical and Environmental Methodologies, Modena (Italy)); Van Woert, M.L. (San Diego State Univ., CA (United States). SeaSpace, Inc.)
This video over the southeastern Mediterranean Sea and down the coastline of the Red Sea was taken by the crew of Expedition 29 aboard the International Space Station. This sequence of shots was ta...
Isotopic Composition and Origin of the Red Sea and Salton Sea Geothermal Brines
Deuterium and oxygen-18 measurements show that the Red Sea and Salton Sea brines are the results of a single process, the leaching of sediments by surface water circulating downward to a geothermal reservoir. The Salton Sea brine is derived from local precipitation but the Red Sea brine originates 1000 kilometers south of its basin, on the shallow sill which controls
H. Craig
Research highlights from the Asian Seas International Acoustics Experiment in the South China Sea
The Asian Seas International Acoustics Experiment (ASIAEX) included two major field programs, one in the South China Sea (SCS) and the other in the East China Sea (ECS). This paper summarizes results from the work conducted during April and May 2000 and 2001 over the continental shelf and slope in the northeastern South China Sea, just east of Dongsha Island
James F. Lynch; Steven R. Ramp; Ching-Sang Chiu; Tswen Yung Tang; Y.-J. Yang; J. A. Simmen
Development and properties of sea ice in the coastal regime of the southeastern Weddell Sea
From October to December 1986 a program consisting of sea ice core analysis in combination with sea ice observations was carried out from the icebreaker R\\/V Polarstern as part of the Winter Weddel Sea Project. The ship operated in the central and southeastern Weddell Sea with interests focusing on the ice shelf front between 70°S and 77°S where a system
Hajo Eicken; Manfred A. Lange
Remote Sensing of Sea Ice in the Northern Sea Route: Studies and Applications
Given the rapid changes that are under way in Arctic sea ice extent, Remote Sensing of Sea Ice in the Northern Sea Route is a timely work. The Northern Sea Route (NSR), along the Arctic coast of Russia, has a long history, dating back to 1932, when the Soviet Union established the NSR administration to develop hydrometeorological services. Shipping along
Roger G. Barry
Ice core records as sea ice proxies: An evaluation from the Weddell Sea region of Antarctica
Ice core records of methanesulfonic acid (MSA) from three sites around the Weddell Sea are investigated for their potential as sea ice proxies. It is found that the amount of MSA reaching the ice core sites decreases following years of increased winter sea ice in the Weddell Sea; opposite to the expected relationship if MSA is to be used as
Nerilie J. Abram; Robert Mulvaney; Eric W. Wolff; Manfred Mudelsee
Ice core records as sea ice proxies: An evaluation from the Weddell Sea region of Antarctica
(1) Ice core records of methanesulfonic acid (MSA) from three sites around the Weddell Sea are investigated for their potential as sea ice proxies. It is found that the amount of MSA reaching the ice core sites decreases following years of increased winter sea ice in the Weddell Sea; opposite to the expected relationship if MSA is to be used
Nerilie J. Abram; Robert Mulvaney; Eric W. Wolff; Manfred Mudelsee
Coastal Consequences of Sea Level Rise
NSDL National Science Digital Library
The ocean's surface is not level, and sea levels change in response to changes in chemistry and temperature. Sophisticated satellite measurements are required for scientists to document current sea level rise. This module explores the evidence for sea level rise related to global climate change and the consequences for humanity, especially coastal-dwelling populations. Students will have the opportunity to analyze interactive data to understand the potential consequences of climate change on sea level in different parts of the world.
Sea level rise in the Arctic Ocean
About 60 tide-gauge stations in the Kara, Laptev, East-Siberian and Chukchi Seas have recorded the sea level change from the 1950s through 1990s. Over this 40-year period, most of these stations show a significant sea level rise (SLR). In light of global change, this SLR could be a manifestation of warming in the Arctic coupled with a decrease of sea
Andrey Proshutinsky; Vladimir Pavlov; Robert H. Bourke
Minimal Antarctic sea ice during the Pliocene
Antarctic sea-ice concentration at Ocean Drilling Program Sites 1165 (64.380°S, 67.219°E) and 1166 (67.696°S, 74.787°E) was lower than today through much of the Pliocene. The low sea-ice concentration is evident from the proportion of the diatom Eucampia antarctica with intercalary valves (Eucampia index). This sea-ice proxy was calibrated by using modern diatom data obtained from core-top samples and winter sea-ice
J. M. Whitehead; S. Wotherspoon; S. M. Bohaty
Ground Wave Propagation over Arctic Sea Ice.
National Technical Information Service (NTIS)
Radio ground wave propagation in the Arctic Ocean occurs over mixed paths. The mixed paths include layered or homogeneous sea ice and sea water. Amplitude and phase variations occurring as 'dropoff' or 'recovery' effects at the ice-sea water boundaries pr...
A. W. Biggs
Sea Grant: Enhancing K-12 Education.
ERIC Educational Resources Information Center
Sea Grant is a major contributor to marine and aquatic education in K-12 classrooms through curriculum development, teacher education, school programs at field sites, and educational research. Describes Sea Grant's efforts in these areas. Specific programs outlined include Operation Pathfinder, Ohio Sea Grant Partnerships for Great Lakes…
Fortner, Rosanne W.
59 FR- Atlantic Sea Scallop Fishery
Federal Register 2010, 2011, 2012, 2013
...061094A] RIN 0648-AG83 Atlantic Sea Scallop Fishery AGENCY: National Marine Fisheries...Framework Adjustment 1 to the Atlantic Sea Scallop Fishery Management Plan (FMP). This...redesignates the fishing year for sea scallops to begin on March 1 each year, and...
59 FR- Atlantic Sea Scallop Fishery
Federal Register 2010, 2011, 2012, 2013
...940368-4068; I.D. 030294C] Atlantic Sea Scallop Fishery AGENCY: National Marine Fisheries...ring size required for Atlantic sea scallop dredges by amendment 4 to the Fishery Management Plan for the Atlantic Sea Scallop Fishery (FMP) and its...
Recent State of Arctic Sea Ice
We present the recent state of Arctic sea ice including observations from 2008 in a context of a multi-decadal perspective. A new record has been set in the reduction of Arctic perennial sea ice extent this winter. As of 1 March 2008, the extent of perennial sea ice was reduced by one million km2 compared to that at the same
S. V. Nghiem; I. G. Rigor; P. Clemente-Colón; D. K. Perovich; J. A. Richter-Menge; Y. Chao; G. Neumann; M. Ortmeyer
Chaotic radar signal processing over the sea
It is demonstrated that the random nature of sea clutter may be explained as a chaotic phenomenon. For different sets of real sea clutter data, a correlation dimension analysis is used to show that sea clutter can be embedded in a finite-dimensional space. The result of correlation dimension analysis is used to construct a neural network predictor for reconstructing the
Henry Leung; Titus Lo
Divide and Conquer (Fertilization of Sea Urchins)
NSDL National Science Digital Library
This activity engages students in direct observation and inquiry-based experiments using sea urchins. First, they observe normal fertilization and division/cleavage in the sea urchin zygote. Next, they develop hypotheses and design and carry out experiments to test factors that can affect the fertilization of sea urchin eggs.
Ms. Mary Elizabeth Kelley (Bethel High School)
Arctic Sea Ice Extent Plummets in 2007
Arctic sea ice declined rapidly to unprecedented low extents in the summer of 2007, raising concern that the Arctic may be on the verge of a fundamental transition toward a seasonal ice cover. Arctic sea ice extent typically attains a seasonal maximum in March and minimum in September. Over the course of the modern satellite record (1979 to present), sea
Julienne Stroeve; Mark Serreze; Sheldon Drobot; Shari Gearheard; Marika Holland; James Maslanik; Walt Meier; Ted Scambos
Sea turtle nesting presents a potential pathway to subsidize nutrient-poor dune ecosystems, which provide the nesting habitat for sea turtles. To assess whether this positive feedback between dune plants and turtle nests exists, we measured N concentration and d15N values in dune soils, leaves from a common dune plant (sea oats (Uniola paniculata)), and addled eggs of loggerhead (Caretta caretta)
Laura B. Hannan; James D. Roth; Llewellyn M. Ehrhart; John F. Weishampel
[Comparative analysis of sea-ice diatom species composition in the seas of Russian Arctic].
Comparative analysis of species composition of ice diatom algae (IDA) of the White, Barents, Kara, Laptev, East Siberian, Chukchi Seas and the Basin of the Arctic Ocean was conducted on the basis of both original and published data. Species composition of IDA counts 567 taxa including 122 centric and 446 pennate diatoms. The freshwater algae composed about 18% of the total species number. In the White Sea, IDA were the most numerous (272 taxa), in the Kara Sea they are the least numerous (57 taxa). The species compositions in different seas differ significantly from each other. Similarity of IDA was consistent with the Arctic Ocean circulation and ice drift. IDA of Chukchi, East Siberian and Laptev Seas are the most similar, as are IDA of White and Kara Seas. Similarity of IDA of Chukchi Sea to those of other seas decrease in the west direction. IDA species differences between regions within one sea could be greater than those between different seas. PMID:19425351
Il'iash, L V; Zhitina, L S
The Impact of Sea Surface Temperature Front on Stratus-Sea Fog over the Yellow and East China Seas
NASA Astrophysics Data System (ADS)
A stratus-sea fog event occurred on 3 June 2011 over the Yellow and East China Seas (as shown in figure) is investigated observationally and numerically. Emphasis is put on the influences of the sea surface temperature front (SSTF) and of the synoptic circulations on the transition of stratus to sea fog. The southerly winds from a synoptic high pressure transport water vapor from the East China Sea to the Yellow Sea, while the subsidence induced by the high contributes to the formation of the temperature inversion on the top of the stratus or stratocumulus that appears mainly over the warm flank of a sea surface temperature front in the East China Sea. Forced by the SSTF, there is a secondary cell within the atmospheric boundary layer (ABL), with a sinking branch on the cold flank and a rising one on the warm flank of the SSTF. This sinking branch, in phase with the synoptic subsidence, forces the stratus or stratocumulus to lower in the elevation getting close to the sea surface as these clouds move northward driven by the southerly winds. The cloud droplets can either reach to the sea surface directly or evaporate into water vapor that may condense again when coming close to the cold sea surface to form fog. In this later case, the stratus and fog may separate. The cooling effect of cold sea surface counteracts the adiabatic heating induced by the subsidence and thus helps the transition of stratus to sea fog in the southern Yellow Sea. By smoothing the SSTF in the numerical experiment, the secondary cell weakens and the sea fog patches shrink obviously over the cold flank of the SSTF though the synoptic subsidence and moist advection still exist. A conceptual model is suggested for the transition of stratus to sea fog in the Yellow and East China Seas, which is helpful for the forecast of sea fog over these areas. The satellite visible image of the stratus-fog event. The fog appears in the Yellow Sea and the stratocumulus in the East China Sea.
Zhang, S.; Li, M.; Liu, F.
Bottom trawling is a non-selective commercial fishing technique whereby heavy nets and gear are pulled along the sea floor. The direct impact of this technique on fish populations and benthic communities has received much attention, but trawling can also modify the physical properties of seafloor sediments, water–sediment chemical exchanges and sediment fluxes. Most of the studies addressing the physical disturbances of trawl gear on the seabed have been undertaken in coastal and shelf environments, however, where the capacity of trawling to modify the seafloor morphology coexists with high-energy natural processes driving sediment erosion, transport and deposition. Here we show that on upper continental slopes, the reworking of the deep sea floor by trawling gradually modifies the shape of the submarine landscape over large spatial scales. We found that trawling-induced sediment displacement and removal from fishing grounds causes the morphology of the deep sea floor to become smoother over time, reducing its original complexity as shown by high-resolution seafloor relief maps. Our results suggest that in recent decades, following the industrialization of fishing fleets, bottom trawling has become an important driver of deep seascape evolution. Given the global dimension of this type of fishery, we anticipate that the morphology of the upper continental slope in many parts of the world's oceans could be altered by intensive bottom trawling, producing comparable effects on the deep sea floor to those generated by agricultural ploughing on land. PMID:22951970
Puig, Pere; Canals, Miquel; Company, Joan B; Martín, Jacobo; Amblas, David; Lastras, Galderic; Palanques, Albert
Internal Waves, South China Sea
NASA Technical Reports Server (NTRS)
Subsurface ocean currents, frequently referred to as internal waves, are frequently seen from space under the right lighting conditions when depth penetration can be achieved. These internal waves observed in the South China Sea off the SE coast of the island of Hainan (18.5N, 110.5E) visibly demonstrate turbidity in the ocean's depths at the confluence of conflicting currents.
Solar sea power plants \\/SSPP
The current state of knowledge about the design and construction of demonstration solar sea power plants (SSPP) is reviewed. Open-cycle and closed-cycle SSPP design concepts are discussed. Consideration of structural strength, corrosion resistance, manufacturing and assembly difficulties, initial cost and maintenance suggests that concrete is the best choice for SSPP construction at any ocean depth above the thermocline. The characteristics
A. M. Strauss
NSDL National Science Digital Library
This site is dedicated to the Great Lakes Sea Grant program. It provides information on the GLSG's priorities and initiatives. Topics of increased importance to the Great Lakes include fisheries and invasive species. Links to sites featuring publications and photos of Great Lakes storms and wildlife.
NSDL National Science Digital Library
Site dedicated to the Great Lakes Sea Grant program. Information on GLSG priorities and initiatives. Topics of increased importance to the Great Lakes include fisheries and invasive species. Links to sites featuring publications and photos of Great Lakes storms and seiches and wildlife.
National Technical Information Service (NTIS)
A feasibility study was made for a salt gradient solar pond power plant in or near the Salton Sea of California. The conclusions support continuance 5-MWe proof-of-concept experiment, and ultimate construction by an electric utility company of a 600-MWe p...
M. L. Peelgren
NASA Astrophysics Data System (ADS)
The tragedy of disappearing of Aral Sea is well known to the World. Before and after collapse of Soviet Union, a huge quantity of scientific and popular editions described with grief the situation around the Aral Sea. After the NIS states became independent, World Bank, UNDP, UNEP in proper competition with each other had provided some assessment of the situation through presentation of some small and medium grants, but after 2000, the local population remained alone with own problems. Although on the eyes of the present generation a unique transformation of great water body into deserts took place, the global scientific community did not find forces and financing for real and detail investigation of the processes accompanying the Sea shrinking and land formation. We should acknowledge and give big respect to NATO, later to German Government that through GTZ (now GIZ) - German International Collaboration Agency - and GFZ (Potzdam) paid attention to this area of environment crisis and organized scientific and protective design in the so-called Priaralie - the territory around the drying Sea and delta of the two rivers - Amudarya and Syrdarya. Thank to this assistance, the local specialists in collaboration with limited a number of foreign scientists (N.Aladin, P.Zavialov, Joop de Schutter, Hans Wilps, Hedi Oberhansli) organized significant works for detail socioeconomic, ecological and hydrological assessment situation in Priaralie and on the Aral sea coast. On this base, Ministry of Agriculture and Water resources of Uzbekistan and State Committee of Water resources of Kazakhstan developed a plan of rehabilitation of Amudarya and Syrdarya deltas and started implementation of these projects. If Kazakh water authority moved ahead in wetland restoration faster, a forestation of delta and drying bed of Aral Sea got big success in Uzbek territory. 244 thousands hectares of saxsaul and tamarix were planted for protection of the Priaralie. By request of GTZ SIC, ICWC organized in 2005-2009 sixth expeditions for complex remote sensing and ground investigations Aral Sea former bottom that were complemented in 2010 -2011 by two expeditions with GFZ. As a result, the landscape, soils and environment mapping was done with determination of ecologically unstable zones and assessment total change of lands situation compared with the pre-independence time. Moreover - methodic of monitoring water, environment and hydro geological indicators on the all deltas area was elaborated, organized its testing and combined with remote sensing data on Amudarya delta for 2009-2012. It permits to SIC ICWC to organize systematic permanent (decadal) monitoring and recording of size, volume and level of water in Aral Sea. Since the beginning of regular observations over the Aral Sea level, 2 periods can be emphasized: 1. Conditionally natural period - 1911-1960 - characterized by a relatively stable hydrological regime, with fluctuations in the level around 53 m and the range of inter-annual fluctuations at no more than 1 m., when the sea received annually about a half of the run-off in the Syrdarya and Amudarya Rivers, i.e. 50-60 km3/yr. 2. Intensive anthropogenic impact period - since the 1960s, a vast extension of irrigable land was carried out in Central Asia that resulted in intensive diversion of river run-off. Since then, the sea level has been falling steadily, causing a dramatic reduction in the water surface area, a decrease in water volume and depths, great changes in shoreline configuration and an expansion of the desert areas adjacent to the Aral Sea. From 1960-1985, when the sea was an integral water body, slight lowering in the sea level took place until the 1970s, when the sea-level decreased with the mean level lowering 1 m. The desiccation process accelerated visibly from the mid 1970s. In 1975-1980, the level decreased by 0.65 m a year on average. Moreover, the level dropped greatly, when the run-off of the Amudarya did not reach the Aral Sea any more (1980-1990). Kokaral was the first of the large islands becoming a peninsula, separa
Dukhovniy, Viktor; Stulina, Galina; Eshchanov, Odylbek
Sea Surface Height 1993 - 2011
This animation depicts year-to-year variability in sea surface height, and chronicles two decades of El Niño and La Niña events. It was created using NASA ocean altimetry data from 1993 to 2011, ...
Deep Sea Moorings Fishbite Problem.
National Technical Information Service (NTIS)
Two types of mooring lines are used in deep sea moorings. One is an unjacketed rope of synthetic fiber. When used for towing and mooring, this type has many favorable properties, but it is highly susceptible to cutting. A second type is a line made of syn...
B. Prindle D. May H. O. Berteaux
NSDL National Science Digital Library
This illustration of Earth's sea surface temperature was obtained from two weeks of infrared observations by the Advanced Very High Resolution Radiometer (AVHRR), an instrument on board NOAA-7, during July 1984. Temperatures are color coded with red being warmest and decreasing through oranges, yellows, greens, and blues. The caption provides a brief description of the features seen in the image.
ERIC Educational Resources Information Center
Describes an activity that simulates exploration techniques used in deep-sea explorations and teaches students how this technology can be used to take a closer look inside volcanoes, inspect hazardous waste sites such as nuclear reactors, and explore other environments dangerous to humans. (DDR)
Montes, Georgia E.
Sea Buckthorn: New Crop Opportunity
Sea buckthorn (Hippophae rhamnoides L., Elaeagnaceae) is a winter hardy, deciduous shrub with yel-low or orange berries (Bailey and Bailey 1978). It develops an extensive root system rapidly and is therefore an ideal plant for preventing soil erosion and land reclamation. It can withstand temperatures from-43? to 40?C (Lu 1992). It is considered to be drought resistant (Heinze and Fiedler
Thomas S. C. Li
SEA modelling of ship structures
NASA Astrophysics Data System (ADS)
Statistical Energy Analysis (SEA) has been used to get analytical estimates, as an alternative method to the empirical one, of the the transmission losses of structure-borne noise along the ship hull, which is one of the most important procedures in predicting cabin noise. Major members such as decks, shell plates, and bulkheads were modeled as subsystems representing flexural and/or in-plane wave groups. The modeling process was relatively simple because only structural members of a cross section were considered. However, when one wishes to obtain more theroetical predictions by using SEA, modeling must include a much larger number of subsystems including air spaces, which is no longer simple, even for the aft-part of a ship. The ship structures are so complicated that it is a difficult job to define subsystems themselves. And the number of subsystems in general is so large that preparing the input data will require enormous efforts. More importantly, numerous empirical factors accumulated in past experience and on-board measurements should be appropriately considered in the SEA modeling. Moreover, taking every detail of the multi-connected structures as subsystems does not necessarily yield more accurate results. In this paper, we discuss various aspects of the SEA modeling of the ship. In particular, we are concerned with the simplifying of complex structures and inclusion of the empirical factors. We suggest some practical techniques, which might be useful in noise analysis of commercial ships.
Kang, Hyun J.; Kim, Hyun S.; Kim, Jae S.; Lee, Young C.
NSDL National Science Digital Library
Award-winning ideas from SEA Semester's educators. This collection of over 25 lesson plans covers topics in marine biology, coastal ecology, chemical and physical oceanography, seafloor geology and nautical science. Each plan includes target grades, keywords, introduction and background, advice on how to best integrate the activities into classroom curriculum, instructions and tips, materials list, procedures, suggestions for evaluation, extensions.
Sea Grant Nonindigenous Species (SGNIS)
NSDL National Science Digital Library
Sea Grant's award winning, comprehensive exotic species resource center with everything from educational materials to research findings on a variety of exotic species. Site features peer-reviewed literature, unreviewed publications, and the outreach section includes a searchable database of reference material covering all aspects of nonindigenous species, including individual exotic species. Also features an outstanding kid's section containing games and information on exotics.
ERIC Educational Resources Information Center
Examines the gravitational effects and the way that local conditions interact with these effects to produce the tides characteristic of the British seas. Presents some effects of tides including the possibility of harnessing tidal energy and the effect of tidal friction on the use of the earth as a clock. (GS)
Sandon, Frank
[Medical emergencies and sea rescue].
Military nurses and doctors are on permanent standby to respond to any medical emergency which may arise at sea. This atypical form of practice is part of a specific organisation, in order to provide optimal, high-quality care in the most remote places of the oceans. PMID:23951619
Lefebvre, Fabien; Albert, Christophe; Gunepin, David; Pondaven, Eric; Querellou, Emgan
NASA Astrophysics Data System (ADS)
Recent research on sea level rise suggests that sea level rise by the end of this century may well be significantly larger than those identified in the IPCC AR4 (2007). Whereas in the past, sea level rise was ascribed equally to thermal expansion of a warming ocean and the melting of land-based ice sheets and glaciers, the recent acceleration in rise rate is largely due to increased loss of land-based ice. Increased Greenland melt has raised important questions about the role moulins, which lubricate the base of the ice sheet and increase its flow to the sea, will play in ice sheet evolution. However, new data indicate that rising ocean temperatures have contributed most significantly to the rapid wastage of glaciers in deep fjords, as calving fronts and grounding lines retreat. Our limited observations, and the fact that models are still catching up to incorporate some of these substantial and fast-acting processes, result in large uncertainties in sea level rise projections. Despite these limitations, we do expect continued sea level rise to be inevitable with progressively increasing temperatures. While it is not clear whether the rate of rise will increase, decrease or remain the same, the current behavior of land-ice, and the fact that sea level rise since 2003 has been nearly twice that of the preceding half century, which itself was significantly larger than that of the late 19th and early 20th centuries, suggests that rates equal to or greater than those of today are a real possibility. Moreover, sea level rise will not be uniform around the globe as mass is redistributed from the polar ice sheets and ocean circulation changes. Some portions of the coasts of the US may see rises 20% larger than the global average, while others may see lower than average rates. This renders some areas of the U.S. much more vulnerable to storm surges than others, with the consequences for coastal states potentially being quite severe. Given the large uncertainty in projections, the magnitude of the potential impacts, and the costs and planning challenges associated with different mitigation and adaptation strategies, improvements of sea level predictions are of great importance. In particular, there is a tremendous need for improvements in models of ice/ocean interactions and ice dynamic and thermodynamic processes. Additionally, sustained observations are needed of ice changes and the ocean and atmospheric processes that control them, as well as the global and regional rates of sea level rise and the associated geodetic and oceanographic processes. Such model advances and sustained observations will enable more credible predictions. In addition, significant progress is needed in interdisciplinary vulnerability assessments of coupled coastal human-environment systems and in efforts to turn scientific results into decision-relevant variables (e.g. erosion rates, changes in flood elevation and frequency, saltwater intrusion rates into coastal aquifers) that can help decision-makers develop cost-effective and socially feasible adaptation strategies.
Abdalati, W.; Moser, S. C.; Schmitt, R. W.
Interannual variability of the Caspian Sea three-dimensional circulation, sea level and air-sea interaction
NASA Astrophysics Data System (ADS)
A three-dimensional primitive equation model including sea ice and air-sea interaction is used to study climatic circulation and water mass variability in the Caspian Sea under the influence of realistic mass, momentum and heat fluxes. The water budget of the landlocked Caspian Sea is extremely sensitive to climatic variability in the surrounding areas, its surface level dynamics is characterized by strong seasonal and decadal variations, which reflect processes occurring in regional climate system. In order to explore these links as well as the climate of the Caspian Sea we develop a numerical model of enclosed sea dynamics, capable to simulate large, up to 10 meters, interannual sea level variations. One of the specific features of the model is that it allows for flooding and drying of coastal area. It is the coastline movement that determines the response of the Caspian Sea level to nonzero water budget. Due to the shallowness and flatness of the Caspian Sea bottom this response is nontrivial and its prediction requires as accurate description of coastal dynamics as possible. Using this model we reconstruct the evolution of the Caspian Sea level and other physical characteristics in the second half of the 20th century. The results of this study suggest that it is crucial for the model to adequately describe processes occurring in the surface and bottom boundary layers, as well as in the coastal region of the sea, in order to predict its level change.
Dyakonov, Gleb; Ibrayev, Rashit
Jet Formation at the Sea Ice Edge
NASA Astrophysics Data System (ADS)
The sea ice edge presents a region of many feedback processes between the atmosphere, ocean and sea ice, which are inadequately represented in current climate models. Here we focus on on-ice atmospheric and oceanic flows at the sea ice edge. Mesoscale jet formation due to the Coriolis effect is well understood over sharp changes in surface roughness such as coastlines. This sharp change in surface roughness is experienced by the atmosphere flowing over, and ocean flowing under, a compacted sea ice edge. We have studied a dynamic sea ice edge responding to atmospheric and oceanic jet formation. The shape and strength of atmospheric and oceanic jets during on-ice flows is calculated from existing studies of the sea ice edge and prescribed to idealised models of the sea ice edge. An idealised analytical model of sea ice drift is developed and compared to a sea ice climate model (the CICE model) run on an idealised domain. The response of the CICE model to jet formation is tested at various resolutions. We find that the formation of atmospheric jets during on-ice winds at the sea ice edge increases the wind speed parallel to the sea ice edge and results in the formation of a sea ice edge jet. The modelled sea ice edge jet is in agreement with an observed jet although more observations are needed for validation. The increase in ice drift speed is dependent upon the angle between the ice edge and wind and can result in a 40% increase in ice transport along the sea ice edge. The possibility of oceanic jet formation during on-ice currents and the resultant effect upon the sea ice edge is less conclusive. Observations and climate model data of the polar oceans has been analysed to show areas of likely atmospheric jet formation, with the Fram Strait being of particular interest.
Heorton, Harry; Feltham, Daniel
Northern Barents Sea Evolution Linked to the Arctic Ocean
NASA Astrophysics Data System (ADS)
The current effort represents a systematic regional study of the vast and poorly sampled area, linking the Barents Sea and the Arctic Ocean. The deep structure of the Northern Barents Sea was examined by means of integration various geophysical techniques, including numerical geodynamic modeling. Ocean Bottom Seismometers data have been acquired east of Svalbard and processed using a seismic refraction/reflection tomography method. A series of crustal-scale geotransects, illustrating the architecture of the Cenozoic Northern Barents Sea margin were constructed using gravity modeling, sparse seismic reflection profiles and depth to magnetic sources estimates. The structure of the Mesozoic passive margin, facing to the Amerasia Basin, was inferred based on a similar technique, involving plate reconstructions. Numerical simulations of the lithosphere extension, leading to formation of the Eurasia Basin, was performed using the finite element method. The velocity structure east of Svalbard exhibits evidences of Cretaceous magmatism. In particular, funnel-shaped high-velocity anomalies, reaching 10% relative to the 1D background model, are interpreted as Early Cretaceous magmatic intrusions. Further to the north, a narrow and steep continent-ocean transition was observed. The conjugate northern (and eastern) Barents Sea - Lomonosov Ridge margins are symmetric and narrow whereas the continent-ocean transition on the Podvodnikov Basin's side of the Lomonosov Ridge is broad. On the continental side, the Northern Barents Sea margin is underlain by Paleozoic-Early Mesozoic deep sedimentary basins separated from the oceanic side by the marginal basement uplift. The Northern Barents Sea, including Svalbard, was not affected by the major Late Jurassic - Early Cretaceous rifting which gave rise to deep basins in the South Western Barents Sea. However, the area experienced widespread Early Cretaceous magmatism. The emplacement of mafic magmas was controlled by Paleozoic rift structures which were reactivated in the Early Cretaceous. The magmatism east of Svalbard developed without significant crustal thinning, but was probably triggered by localized lithospheric weakness zones. The Mesozoic passive margin, originated due to the opening of the Podvodnikov Basin, was subjected to significant crustal thinning. The Northern Barents Sea region together with the Lomonosov Ridge was standing high during most of the Late Cretaceous. The regional uplift sourced from the Alpha Ridge area. The Eurasia Basin's breakup in the Paleocene preceded the opening of the Norwegian Sea, implying a connection to the Labrador Sea. A short-lived lithosphere-scale shear zone has likely facilitated to the detachment of the Lomonosov Ridge microcontinent and onset of seafloor spreading. Shear heating in the mantle lithosphere accompanied the development of the proposed shear zone and served as a mechanism for strain localization.
Minakov, A.; Mjelde, R.; Faleide, J. I.; Huismans, R. S.; Dannowski, A.; Flueh, E. R.; Glebovsky, V.; Keers, H.; Podladchikov, Y. Y.
Thermal biology of sea snakes and sea kraits.
Temperature probably had no direct effect on the evolution of sea kraits within their center of origin, a geologically stable thermal zone straddling the equator, but may have indirectly affected expansions and contractions in distributions beyond that zone through global fluctuations that caused alternation of higher and lower sea levels. The northern limit of the Laticauda colubrina complex seems to be the 20°C isotherm; in the south, the range does not reach that isotherm because there is no land (also a habitat requirement of sea kraits) within the zone of suitable temperature. The relationship of temperature to the pattern of geographic variation in morphology supports either the hypothesis of peripheral convergence or the developmental hypothesis but does not distinguish between them. Quadratic surfaces relating cumulative scores for coloration and morphological characters to global position showed a strong latitudinal component and an even stronger longitudinal one in which the direction of the latitudinal effect was reversed between east and west. A multivariate analysis revealed that while morphological characters vary significantly by location and climate when tested separately, when the influence of location on morphology is taken into account, no residual relationship between climate and morphology remains. Most marine snakes have mean upper temperature tolerances between 39°C and 40°C and operate at temperatures much nearer their upper thermal limits than their lower limits but still avoid deleterious extremes by diving from excessively hot water to deeper, cooler strata, and by surfacing when water is cold. At the surface in still water in sunlight, Pelamis can maintain its body temperature slightly above that of the water, but whether this is significant in nature is questionable. As temperature falls below 18-20°C, survival time is progressively reduced, accompanied by the successive occurrence of cessation of feeding, cessation of swimming, and failure to orient. Acclimation does not seem to be in this species' repertoire. In the water column, marine snakes track water temperature; on land, sea kraits can thermoregulate by basking, selecting favorable locations, and by kleptothermy. Laticauda colubrina adjusts its reproductive cycle geographically in ways that avoid breeding in the coldest months. Mean voluntary diving time is not temperature-dependent within the normal range of temperatures experienced by marine snakes in the field, but is reduced in water colder than 20°C. On land, much as while diving in the sea, sea kraits maintain long periods of apnea; intervals between breaths are inversely related to temperature. PMID:22669175
Heatwole, Harold; Grech, Alana; Monahan, John F; King, Susan; Marsh, Helene
Diffuse reflection coefficient of a stratified sea.
A differential equation of a Riccati type for the diffuse reflection coefficient of a stratified sea is proposed. For a homogeneous sea with arbitrary inherent optical properties this equation is solved analytically. For an inhomogeneous sea it is solved approximately for any arbitrary stratification. The resulting equation expresses the diffuse reflection coefficient of the sea through vertical profiles of absorption and backscattering coefficients, bottom albedo, and sea depth. The results of calculations with this equation are compared with Monte Carlo computations. It was found that the precision of this approach is in the range of 15%. PMID:18305694
Haltrin, V I
Ecological consequences of sea-ice decline.
After a decade with nine of the lowest arctic sea-ice minima on record, including the historically low minimum in 2012, we synthesize recent developments in the study of ecological responses to sea-ice decline. Sea-ice loss emerges as an important driver of marine and terrestrial ecological dynamics, influencing productivity, species interactions, population mixing, gene flow, and pathogen and disease transmission. Major challenges in the near future include assigning clearer attribution to sea ice as a primary driver of such dynamics, especially in terrestrial systems, and addressing pressures arising from human use of arctic coastal and near-shore areas as sea ice diminishes. PMID:23908231
Post, Eric; Bhatt, Uma S; Bitz, Cecilia M; Brodie, Jedediah F; Fulton, Tara L; Hebblewhite, Mark; Kerby, Jeffrey; Kutz, Susan J; Stirling, Ian; Walker, Donald A
Sea Ice Thickness Variability in Fram Strait
NASA Astrophysics Data System (ADS)
On this poster, we show results from airborne electromagnetic (EM) sea ice thickness measurements demonstrating the temporal and spatial complexity of the ice thickness distribution in Fram Strait between Greenland and Svalbard. Knowledge about the spatial and temporal sea ice thickness distribution in the Arctic Ocean is necessary to assess the state of the sea-ice cover, and to understand relevant processes and changes. Since 2003, the Norwegian Polar Institute (NPI) has been conducting systematic in situ monitoring of sea ice thickness in the western Fram Strait, using both ground and airborne techniques. Fram Strait is a key region for large-scale ice dynamics in the Arctic. It represents the main export route for sea ice from the Arctic and the only deep strait connecting the interior Arctic Ocean and the rest of the world oceans. The ice thickness distribution in this region is the result of a combination of dynamic and thermodynamic sea ice processes. Transects for airborne EM observations were flown by NPI in spring 2005, 2008, and late summer 2010, and by the Alfred Wegener Institute in spring 2009. The regional ice thickness distributions are supplemented with ground measurements including snow thickness observations taken on ice stations during ship expeditions in spring 2005, 2007, and 2008 and annually in late summer from 2003 to 2011. From all these observations, we can show the differing characteristics of the thickness distributions in spring (2005, 2008, 2009) and late summer (2010) when the ice thickness is at its annual maximum (end of the freezing period) and minimum (end of the melting period), respectively. The ice thickness distribution can also vary spatially over short distances in north-south direction. Features such as the East Greenland Polynya, which varies in size for a given time from year to year, contribute to the spatial and temporal variability on the Greenlandic Shelf. In spring 2005, a gradient is visible across Fram Strait from thinner pack ice at the eastern ice edge towards thicker pack ice on the Greenland shelf in the western part of Fram Strait with thick multiyear ice. The spring modal thickness ranged from about 2 m to 3.5 m. In contrast, the spatial variability of the modal thickness in 2008 is larger than observed in the previous campaigns with a wider range of modal ice thicknesses, predominantly due to thinner ice than in 2005. Finally, during late summer 2010 modal thicknesses in the central and eastern part of Fram Strait ranged from about 1 to 2 m. At the same time distributions were in general narrower than observed in previous years, showing a decrease of the fraction of thick pressure ridges. Thick ice was measured only in the westernmost part of Fram Strait. These observations are in agreement with a reported trend towards a generally larger amount of first-year ice versus multiyear ice in the Arctic.
Gerland, S.; Renner, A.; Haas, C.; Nicolaus, M.; Granskog, M.; Hansen, E.; Hendricks, S.; Hudson, S. R.; Beckers, J.; Goodwin, H.
Pathways of inflow and dispersion of warm waters in the Nordic seas
NASA Astrophysics Data System (ADS)
In this study, we use 22 acoustically tracked RAFOS floats to examine the routes and spreading of warm North Atlantic waters entering the Norwegian Sea between Iceland and the Faroes. The majority of floats crossed the Iceland-Faroe Ridge at the eastern end where it is deepest. They joined the Iceland-Faroe Front, but rather than continue north with the outer branch of the Norwegian Atlantic Current into the Nordic seas, most of them jumped over to the inner branch, which continues the inflow through the Faroe-Shetland Channel northeast over the Vøring Plateau toward the Lofoten Basin. Indeed, 17 floats, whether deployed near Iceland or the Faroes, did so; only 2 floats continued north along the outer branch. Despite the small numbers, these results highlight (1) the strong influence of topography on flow patterns, (2) the strong crossover of Iceland-Faroes waters to the inner branch, and (3) the rapid and structured spreading into the Nordic seas.
Rossby, T.; Prater, M. D.; SøIland, H.
Sea ice as a source of sea salt aerosol: A trajectory study of 25 years of year-round sea salt aerosol record at Neumayer, Antarctica
Recently it was recognized that sea ice is a source of sea salt aerosols in coastal Antarctica, playing a more important role than open ocean during winter time. Frost flowers which grow on the surface of newly-formed sea ice are considered to contribute to the generation of sea salt aerosols. The exact mechanism of the release of sea salt aerosols
X. Tian-Kunze; L. Kaleschke; R. Weller; G. König-Langlo; D. Wagenbach; S. Rast; G. Santos; A. Richter; M. Begoin
The distribution and diversity of sea cucumbers in the coral reefs of the South China Sea, Sulu Sea and Sulawesi Sea
NASA Astrophysics Data System (ADS)
A study on the distribution and diversity of sea cucumbers in the coral reefs of the South China Sea, Sulu Sea and Sulawesi Sea was carried out in July 2009. The survey was done using wandering transect underwater with SCUBA. Twelve species of sea cucumber were found from four different families and nine genera. The most dominant family was Holothuriidae (five species), followed by Stichopodidae (three species), Synaptidae (three species) and Cucumariidae with only one species. The most dominant species found around the island was Pearsonothuria graffei, which can be found abundantly on substrate of dead corals in a wide range of depth (6-15 m). The Sulawesi Sea showed a higher diversity of sea cucumber with seven different species compared to the South China Sea with only six different species and Sulu Sea with only two species. Ordination by multidimensional scaling of Bray-Curtis similarities clustered the sampling locations to three main clusters with two outgroups. Previous studies done indicated a higher diversity of sea cucumber as compared to this study. This can be indication that the population and diversity of sea cucumbers in the reef is under threat.
Woo, Sau Pinn; Yasin, Zulfigar; Ismail, Siti Hasmah; Tan, Shau Hwai
A North Sea and Baltic Sea model ensemble eutrophication assessment.
A method to combine observations and an ensemble of ecological models is suggested to produce a eutrophication assessment. Using threshold values and methodology from the Oslo and Paris Commissions (OSPAR) and the Helsinki Commission (HELCOM), four models are combined to assess eutrophication for the Baltic and North Seas for the year 2006. The assessment indicates that the entire southeastern part of the North Sea, the Kattegat, the Danish Straits, the Gulf of Finland, and the Gulf of Riga as well as parts of the Arkona Basin, the Bornholm Basin, and the Baltic proper may be classified as problem areas. The Bothnian Bay and parts of the Baltic proper, the Bornholm Basin, and the Arkona Basin are classified as potential problem areas. This method is a useful tool for the classification of eutrophication; however, the results depend on the threshold values, and further work is needed within both OSPAR and HELCOM to harmonize these values. PMID:20496653
Almroth, Elin; Skogen, Morten D
Changes in extreme sea-levels in the Baltic Sea
NASA Astrophysics Data System (ADS)
In a climate change context changes in extreme levels rather than changes in the mean are of particular interest in view of its importance for coastal protection. In this work extreme sea-levels in the Baltic sea are investigated from daily tide gauge records for the period 1916-2005 using the block maxima approach on annual means. Extreme events are analyzed based on the Generalized Extreme Value (GEV) distribution considering both stationary and time-varying models. The likelihood ratio test is applied to select between stationary and non-stationary models for the maxima and return values are estimated from the final model. As an independent and complementary approach quantile regression is applied for comparison with the results from extreme value theory. The rates of change in the uppermost quantiles are in general consistent and more pronounced for the northernmost stations.
Ribeiro, Andreia; Barbosa, Susana
Lithosphere-scale 3D gravity modelling of the Barents Sea and Kara Sea
NASA Astrophysics Data System (ADS)
The Barents - Kara Sea region covers the major part of the European Arctic shelf. Its northern and western boundaries are young passive margins which originate from early Paleocene-Eocene opening of the Eurasia Basin and the Norwegian-Greenland Sea. In contrast, the basement of the Barents and Kara shelves has been consolidated much earlier, during three major late Precambrian to Permian orogenies. Additionally, the shelf experienced multiple episodes of localised subsidence which resulted in the formation of ultra-deep sedimentary basins varying strongly in their geometry between different subregions. Consequently, the preserved sedimentary record is interrupted by major megasequence boundaries that are well-described in the western Barents Sea. Using this subdivision for the sedimentary record, we traced four major megasequence boundaries across the Barents and Kara shelves by analysing interpreted seismic refraction and reflection data, geological maps and previously published 3D-models. We integrate this shallow information into a 3D geological model and complement the latter downward with the top crystalline crust, the Moho and a new lithosphere-asthenosphere boundary. The sedimentary units have been assigned physical properties considering the respective lithology to calculate a depth-dependent density distribution. Thereby, the obtained bulk densities also account for late Cenozoic uplift/erosion and the maximum Pleistocene ice sheet thickness. For the lithospheric mantle, the density distribution is constrained by an earlier published velocity model (Levshin et al., 2007). On the base of isostatic calculations and 3D gravity modelling the density configuration of the crystalline crust and the geometry of potential high-density bodies is investigated. Finally, we correlate preserved sediment maxima and reconstructed erosion maps with subsedimentary velocity and density variations to gain new insights into the development of Barents and Kara Sea basins. Levshin, A. L., Schweitzer, J., Weidle, C., Shapiro, N. M., & Ritzwoller, M. H. (2007). Surface wave tomography of the Barents Sea and surrounding regions. Geophysical Journal International, 170(1), 441-459. doi:10.1111/j.1365-246X.2006.03285.x
Klitzke, P.; Faleide, J.; Sippel, J.; Scheck-Wenderoth, M.
Inter-annual and decadal sea level variations in the north-western Pacific marginal seas
NASA Astrophysics Data System (ADS)
Long term sea level changes in the Okhotsk, Japan/East, East China and Yellow Seas have been explored based on mean monthly values of sea level from tide gauge and altimetry measurements. The analysis of low frequency sea level variability reveals clearly differentiated areas: the Okhotsk Sea and the northern sector of the Japan/East Sea display lower sea level variances and no sea level rise. The southern Japan/East Sea presents larger sea level variability associated with the circulation regime of the warm current entering through the Tsushima Strait and inter-annual sea level variations that are driven by steric and atmospheric changes. The largest sea level variances are found in the Yellow Sea due to the effect of atmospheric forcing over the continental shelf. Inter-annual variability is spatially varying within the Yellow Sea and the East China Sea and is mainly related to the steric sea level changes. Regional mean sea level indices have been synthesized for each area using the longest tide gauge records and have revealed correlations between the southern Japan/East and Yellow Seas with PDO and NP climatic indices. Linear trends at coastal sites in the Japan/East, East China and Yellow Seas show a rather heterogeneous pattern, with values between -1.5 and 5.5 mm/yr for the period 1960-2000. During the period 1993-2008 linear trends derived from coastal tide gauges and from altimetry observations are coherent and reveal a southwards increasing pattern with maximum averaged values reached at the Yellow Sea (4.9 ± 1.9 mm/yr) followed by the Japan/East Sea (3.8 ± 0.9 mm/yr). Decadal rates of sea level change show distinct behaviour among basins as well as with the global average. The southern Japan/East Sea, the East China Sea and the Yellow Sea display decadal variability which is out of phase with respect to the global values.
Marcos, Marta; Tsimplis, Michael N.; Calafat, Francesc M.
Eemian sea-level highstand in the eastern Baltic Sea linked to long-duration White Sea connection
NASA Astrophysics Data System (ADS)
Revised diatom and new dinoflagellate cyst and benthic foraminiferal data from the eastern Baltic Sea have refined our understanding of Eemian (Last Interglacial; 131-119.5 ka) sea-level change on the Russian Karelia, a former seaway linking the Baltic to the White Sea. Results from Peski, eastern Baltic show the initiation of marine conditions just before 131 ka in the latest Saalian, after the opening of a connection to the North Sea. Following the onset of the Eemian marine highstand and the opening of the White Sea connection at around 130.25 ka, near-fully marine conditions persisted in the eastern Baltic area for ca 6 kyr, until ca 124 ka. For most of the Eemian, a strong thermal stratification in the eastern Baltic resulted from an Arctic and possible North Atlantic water component from the White Sea merging with warmer waters from the North Sea. From ca 124 ka, decreasing salinity indicates the end of the marine highstand and a simultaneous closure of the Baltic Sea-White Sea connection, i.e. a duration of ca 6 kyr for this seaway. The main influence of White Sea inflow appears to be restricted to the eastern Baltic area, although a large submerged area in the Russian Karelia associated with temperate Atlantic waters could have assisted in creating a more oceanic climate for Central Europe.
Miettinen, Arto; Head, Martin J.; Knudsen, Karen Luise
Variability and Trends in Sea Ice Extent and Ice Production in the Ross Sea
NASA Technical Reports Server (NTRS)
Salt release during sea ice formation in the Ross Sea coastal regions is regarded as a primary forcing for the regional generation of Antarctic Bottom Water. Passive microwave data from November 1978 through 2008 are used to examine the detailed seasonal and interannual characteristics of the sea ice cover of the Ross Sea and the adjacent Bellingshausen and Amundsen seas. For this period the sea ice extent in the Ross Sea shows the greatest increase of all the Antarctic seas. Variability in the ice cover in these regions is linked to changes in the Southern Annular Mode and secondarily to the Antarctic Circumpolar Wave. Over the Ross Sea shelf, analysis of sea ice drift data from 1992 to 2008 yields a positive rate of increase in the net ice export of about 30,000 sq km/yr. For a characteristic ice thickness of 0.6 m, this yields a volume transport of about 20 cu km/yr, which is almost identical, within error bars, to our estimate of the trend in ice production. The increase in brine rejection in the Ross Shelf Polynya associated with the estimated increase with the ice production, however, is not consistent with the reported Ross Sea salinity decrease. The locally generated sea ice enhancement of Ross Sea salinity may be offset by an increase of relatively low salinity of the water advected into the region from the Amundsen Sea, a consequence of increased precipitation and regional glacial ice melt.
Comiso, Josefino; Kwok, Ronald; Martin, Seelye; Gordon, Arnold L.
Assessment of 137Cs and 90Sr Fluxes in the Barents Sea
NASA Astrophysics Data System (ADS)
On the basis of published and own data the annual balance of radionuclide income/outcome was assessed for 137Cs and 90Sr in the Barents Sea for the period from 1950s to the presnt. The scheme of the isotope balance calculation in the Barents Sea included the following processes:atmospheric fallout; river run-off; liquid radioactive wastes releases, income from the Norwegian and the White Seas; outflow to the adjacent areas through the Novaya Zemlya straits and the transects Svalbard-Franz Josef Land and Franz Josef Land-Novaya Zemlya; radioactive decay. According to the multiyear dynamics, the inflow of 137Cs and 90Sr to the Barents Sea was significantly preconditioned by currents from the Norwegian Sea. Three peaks of 137Cs and 90Sr isotope concentrations were registered for the surface waters on the western border of the Barents Sea. The first one was observed in the mid-1960s and was conditioned by testing of nuclear weapons. The increase of isotope concentrations in 1975 and 1980 was preconditioned by the discharge of atomic waste by the Sellafield nuclear reprocessing plant. Nowadays, after the sewage disposal plant was built, the annual discharge of nuclear waste from Sellafield plant is low. The Norwegian Sea was a major source of 137Cs and 90Sr isotope income into the Barents Sea for the period of 1960-2014. Currently, the transborder transfer of 90Sr and 137Cs from the Norwegian Sea into the Barents Sea constitutes about 99% of income for each element. Atmospheric precipitation had a major impact in the 1950-1960s after the testing of the nuclear weapons, and in 1986 after the accident at Chernobyl Nuclear Power Station. In 1963, the atmospheric precipitation of 137Cs reached 1050 TBq; and that of 90Sr, 630 TBq. In 1986, a significant amount of 137Cs inflow (up to 1010 TBq/year) was registered. The 137Cs isotope income exceeded the 90Sr income in the 1960s-1980s, and equal amounts penetrated into the Barents Sea from the Norwegian Sea in the 1990s. Before the 1990s, 137Cs inflow exceeded outflow in the annual balance, but the opposite pattern is observed nowadays. This tendency of prevailing of 137Cs outflow processes in the Barents Sea may be explained by natural decay and ecosystem self-cleaning of the radioactivity, which has penetrated previously. According to our assumptions, in total, 37400 TBq of 137Cs penetrated, and 26300 TBq of 137Cs were output from the Barents Sea during the period 1950-2010, i.e., 70.2% of this isotope was removed. From the 1960s through the present, the inflow of 90Sr exceeded the outflow. In total, 24800 TBq of 90Sr penetrated, and 19600 TBq of 90Sr were output through the northern and northeastern margins of the Barents Sea, i.e., 79.1% of this isotope was removed. From 1960 through the 1980s, the income/outcome ratio in the Barents Sea was quite stable and constituted 1.4-1.5 for 137Cs and 1.1-1.2 for 90Sr. The increase of the impact of atmospheric precipitation on 137Cs income was up to 42% in 1986 due to the Chernobyl disaster, and the income/outcome ratio increased to 2.6. The atmospheric income of 90Sr in 1986 was minor, and the ratio stayed the same for this isotope.
Matishov, Gennady; Usiagina, Irina; Kasatkina, Nadezhda; Ilin, Gennadii
NSDL National Science Digital Library
This fun Web article is part of OLogy, where kids can collect virtual trading cards and create projects with them. Here, they learn about deep sea vents. Kids are introduced to these underwater geysers and to the Alvin submersible by Ro Kinzler, an Earth scientist at the Museum. They then have the opportunity to travel to the bottom of the ocean aboard a virtual submersible, learning about the zones they pass through and their inhabitants. A game allows kids to explore and collect specimens from one of the mineral chimneys found at a deep sea vent. When they have collected all nine living things at the vent, they are rewarded with a desktop image.
Open Ocean Bilging, Arabian Sea
NASA Technical Reports Server (NTRS)
These dual oil slicks on the ocean surface are the result of tanker ships flushing their tanks (bilging) in the Arabian Sea (18.5N, 62.5E). These two ships flushed out their bilges, apparently contaminated with bunker oil, leaving oily residues on the ocean's surface. One wake, believed to have been done earlier than the other, has been broadened by the effects of surface winds and current.
Swimming with Sea Cows: Manatees
NSDL National Science Digital Library
When manatees were first seen by Columbus, he thought they were mermaids..but he had been at sea for a long time! Today these gentle marine mammals are threatened by loss of habitat and collisions with boats. This video segment explores the endangered manatees of Florida and their struggle to survive, as well as some of the people who are working to save them. Please see the accompanying lesson plan for educational objectives, discussion points and classroom activities.
Productions, Jonathan B.
Analysis of Yellow Sea circulation
Some features of the circulation in the Yellow Sea (hereafter referred to as YS) in the cold season (mid-November through\\u000a mid-April) are analyzed emphatically by using the observations of several large-scale surveys in recent years together with\\u000a historical data. Compared with the previous studies, a wealth of observed data have firstly been used in this study to further\\u000a discuss the
Jiayie Zang; Yuxiang Tang; Emei Zou; Heung-Jae Lie
Modelling past sea ice changes
NASA Astrophysics Data System (ADS)
A dominant characteristic of the available simulations of past sea ice changes is the strong link between the model results for modern and past climates. Nearly all the models have similar extent for pre-industrial conditions and for the mid-Holocene. The models with the largest extent at Last Glacial Maximum (LGM) are also characterized by large pre-industrial values. As a consequence, the causes of model biases and of the spread of model responses identified for present-day conditions appear relevant when simulating the past sea ice changes. Nevertheless, the models that display a relatively realistic sea-ice cover for present-day conditions often display contrasted response for some past periods. The difference appears particularly large for the LGM in the Southern Ocean and for the summer ice extent in the Arctic for the early Holocene (and to a smaller extent for the mid-Holocene). Those periods are thus key ones to evaluate model behaviour and model physics in conditions different from those of the last decades. Paleoclimate modelling is also an invaluable tool to test hypotheses that could explain the signal recorded by proxies and thus to improve our understanding of climate dynamics. Model analyses have been focused on specific processes, such as the role of atmospheric and ocean heat transport in sea ice changes or the relative magnitude of the model response to different forcings. The studies devoted to the early Holocene provide an interesting example in this framework as both radiative forcing and freshwater discharge from the ice sheets were very different compared to now. This is thus a good target to identify the dominant processes ruling the system behaviour and to evaluate the way models represent them.
Goosse, H.; Roche, D. M.; Mairesse, A.; Berger, M.
The SEAS study is a prospective national, multicentre, multidisciplinary, cohort study in which the cardiac abnormalities following aneurysmal subarachnoid haemorrhage are studied. Incidence, clinical implications and predictive variables of cardiac abnormalities following aneurysmal subarachnoid haemorrhage will be studied. Cardiac abnormalities are defined as ECG changes, echocardiographic function abnormalities, and biochemical changes. A total of 350 patients will be included over a period of three years including follow-up. ImagesFigure 1
van der Bilt, I.A.C.; Hasan, D.; Rinkel, G.J.E.; Wilde, A.A.M.; Visser, F.C.
Chemistry in Titan's Hydrocarbon Seas
NASA Astrophysics Data System (ADS)
Multiple lines of evidence from the Cassini-Huygens mission demonstrate that Titan's large lakes and seas are composed of liquid ethane and methane. In addition to the aforementioned constituents, recent work on solubility indicates that propane, dissolved acetylene and nitriles will be significant components (Cordier, D. et al., ApJ v. 707, 128, 2009). Here we make a preliminary examination of the kinds of chemistry that might occur in such a multicomponent organic solution at temperatures of 90 K subject to various energy sources including modulations of solar heating on seasonal and longer timescales (Aharonson et al., Nature Geoscience v. 2 851, 2009), cosmic rays, and (more speculatively) regional cryovolcanism. It is known that carbon cations (C+) can form in methane, and thus these cations might be found in the liquid methane and ethane comprising the polar seas of Titan. As a result, the methane would become a weak protic solvent, which opens the possibility of methane and its sister alkanes participating in more vigorous organic reactions and erosional processes with the surrounding bedrock than previously thought. We apply these considerations to several problems: (a) We calculate rates of chemical erosion of geological features surrounding the large seas, assuming the surrounding country rock to be (i) water, (ii) water-ammonia, (iii) solid organics. (b) We recompute the solubility of minor polar constituents in the seas, which should be enhanced thanks to the protic behavior of the methane. (c) Non-aqueous biochemistries in hydrocarbon liquids such as those proposed by Benner et al. (Current Opinions in Chem. Bio. v. 8, 672-689) will be aided by the potential for enhanced polarity of the liquid. This work was supported by the NASA Astrobiology Institute, and the program "Incentivazione alla mobilita' di studiosi straineri e italiani residenti all'estero."
Lunine, Jonathan I.; Jacobs, Norman; Cordier, Daniel; Mousis, Olivier
NSDL National Science Digital Library
Are you a teacher who is interested in oceanographic research? Does the idea of living aboard an ocean-going research vessel intrigue you? Would you like to work as a crew member on a one to three week scientific cruise? NOAA is looking for motivated teachers (K-16) with a desire to do scientific research at sea and share that experience with students and colleagues.
The Bering Sea contains three hydrocarbon provinces: shelf, slope, and abyssal basin. The shelf province, which is underlain by three exceptionally large sedimentary basins, has been extensively covered by geophysical surveys. Exploration in this province has not discovered economic hydrocarbon deposits. Frontier basins, with future economic prospects, lie beneath the mostly unexplored slope and abyssal provinces of the Aleutian and Bowers basins of the Bering Sea. These expansive deep-water basins cover an area nearly two-thirds the size of Alaska. Sedimentary rocks of late Mesozoic(.) and Tertiary age make up the 3 to 11-km thick section that covers the entire area. These pelagic and fine-grained terrigenous rocks overlie slowly subsiding oceanic crust, which was trapped in the Bering Sea after the Aleutian Ridge formed during the Eocene. Thick (6-11 km) sedimentary sections and high basement relief (0.5-1.0 km) underlie parts of the 1700-km long Beringian-Koryak slope and rise. At the base of the margin, nearly flat strata of the Aleutian basin drape and onlap faulted acoustic-basement rock. Sparse information from the Deep Sea Drilling Project and US Geological Survey dredging indicates that source and reservoir rocks may exist within the upper and, possibly, lower parts of the sedimentary section. Beneath the central part of the abyssal basin, the sedimentary sequence is only 2-4 km thick, and buried basement relief is greater than 1.0 km. Near-surface temperature gradients are high (average = 58/sup 0/C/km), and acoustic anomalies that may be indicative of hydrocarbons are present. The slope and abyssal basins of the Beringian-Koryak margin have received minimal exploratory attention because water depths that cover the area are typically 2000-3700 m. Advances in deep-water production technology will eventually make these frontier basins attractive for hydrocarbon exploration.
Cooper, A.K.; Marlow, M.S.; Scholl, D.W.
Zusmmenfassung Die Hyaloclastiten entstehen hauptsächlich durch submarines Zerspratzen von Lava, die bei vulkanischen Explosionen im Meer ausgeworfen wurde.Zahlreiche sea-monts waren wahrscheinlich niemals vulkanische Inseln, die später abgestumpft und überschwemmt wurden, wie es allgemein angenommen wird. Wir sind überzeugt, daß ein großer Teil der Vulkane sich unter Wasser gebildet hat aus Laven, die aus einem langlebigen Zufuhrkanal gefördert wurden und die allmählich
Haroun Tazieff
NASA Astrophysics Data System (ADS)
The extent of Arctic sea ice dropped to 3.41 million square kilometers on 16 September, 760,000 square kilometers below the minimum ice extent in 2007, which had been the low mark since the satellite record began in 1979, the National Snow and Ice Data Center (NSIDC) announced. Overall ice extent is 50% below where it was in the 1970s, NSIDC research scientist Walt Meier said during a 19 September briefing. He added that there is also a decrease in ice thickness. Meier said that sea ice varies from year to year with lots of ups and downs. "We wouldn't expect it to keep going down, straight off the map so to speak," he said. "Typically after a record low, we've seen it rebound." Meier added that the general long-term trend is for the Arctic to continue to become generally ice free. He said it is difficult to know how long it will take for that condition to be reached; because of strong variations, Arctic sea ice extent could plateau for some time.
Showstack, Randy
MODIS Global Sea Surface Temperature
NASA Technical Reports Server (NTRS)
Every day the Moderate-resolution Imaging Spectroradiometer (MODIS) measures sea surface temperature over the entire globe with high accuracy. This false-color image shows a one-month composite for May 2001. Red and yellow indicates warmer temperatures, green is an intermediate value, while blues and then purples are progressively colder values. The new MODIS sea surface temperature product will be particularly useful in studies of temperature anomalies, such as El Nino, as well as research into how air-sea interactions drive changes in weather and climate patterns. In the high resolution image, notice the amazing detail in some of the regional current patterns. For instance, notice the cold water currents that move from Antarctica northward along South America's west coast. These cold, deep waters upwell along an equatorial swath around and to the west of the Galapagos Islands. Note the warm, wide currents of the Gulf Stream moving up the United States' east coast, carrying Caribbean warmth toward Newfoundland and across the Atlantic toward Western Europe. Note the warm tongue of water extending from Africa's east coast to well south of the Cape of Good Hope. MODIS was launched in December 1999 aboard NASA's Terra satellite. For more details on this and other MODIS data products, please see NASA Unveils Spectacular Suite of New Global Data Products from MODIS. Image courtesy MODIS Ocean Group, NASA GSFC, and the University of Miami
Respiration in neonate sea turtles.
The pattern and control of respiration is virtually unknown in hatchling sea turtles. Using incubator-raised turtles, we measured oxygen consumption, frequency, tidal volume, and minute volume for leatherback (Dermochelys coriacea) and olive ridley (Lepidochelys olivacea) turtle hatchlings for the first six days after pipping. In addition, we tested the hatchlings' response to hypercapnic, hyperoxic, and hypoxic challenges over this time period. Hatchling sea turtles generally showed resting ventilation characteristics that are similar to those of adults: a single breath followed by a long respiratory pause, slow frequency, and high metabolic rate. With hypercapnic challenge, both species responded primarily by elevating respiratory frequency via a decrease in the non-ventilatory period. Leatherback resting tidal volume increased with age but otherwise, neither species' resting respiratory pattern nor response to gas challenge changed significantly over the first few days after hatching. At the time of nest emergence, sea turtles have achieved a respiratory pattern that is similar to that of actively diving adults. PMID:17258487
Price, Edwin R; Paladino, Frank V; Strohl, Kingman P; Santidrián T, Pilar; Klann, Kenneth; Spotila, James R
Biogeochemistry in Sea Ice: CICE model developments
Polar primary production unfolds in a dynamic sea ice environment, and the interactions of sea ice with ocean support and mediate this production. In spring, for example, fresh melt water contributes to the shoaling of the mixed layer enhancing ice edge blooms. In contrast, sea ice formation in the fall reduces light penetration to the upper ocean slowing primary production in marine waters. Polar biogeochemical modeling studies typically consider these types of ice-ocean interactions. However, sea ice itself is a biogeochemically active medium, contributing a significant and, possibly, essential source of primary production to polar regions in early spring and fall. Here we present numerical simulations using the Los Alamos Sea Ice Model (CICE) with prognostic salinity and sea ice biogeochemistry. This study investigates the relationship between sea ice multiphase physics and sea ice productivity. Of particular emphasis are the processes of gravity drainage, melt water flushing, and snow loading. During sea ice formation, desalination by gravity drainage facilitates nutrient exchange between ocean and ice maintaining ice algal blooms in early spring. Melt water flushing releases ice algae and nutrients to underlying waters limiting ice production. Finally, snow loading, particularly in the Southern Ocean, forces sea ice below the ocean surface driving an upward flow of nutrient rich water into the ice to the benefit of interior and freeboard communities. Incorporating ice microphysics in CICE has given us an important tool for assessing the importance of these processes for polar algal production at global scales.
Jeffery, Nicole [Los Alamos National Laboratory; Hunke, Elizabeth [Los Alamos National Laboratory; Elliott, Scott [Los Alamos National Laboratory; Turner, Adrian [Los Alamos National Laboratory
Sources of Sea Salts to Coastal Antarctica
NASA Astrophysics Data System (ADS)
Coastal Antarctic sea salt aerosols are partitioned into two main sources, namely ocean sea spray and surface sea ice. The sea spray source is related to windiness over the surface ocean and the action of bubbles bursting. The sea ice source is due to frost flowers which form on the surface of sea ice, which are concentrated in sea salts and are lofted by wind action over the sea ice zone. At high accumulation coastal sites, with seasonal resolution, it is possible to estimate the sources of both using deviations of the sodium to sulphate ratio from that found in seawater. To date, from ice core records in east Antarctica (including iceberg B09B near the Mertz Glacier, Law Dome, Wilkes Land and Wilhelm II land), we have found that the source strength from surface sea ice to the Antarctic ice sheet diminishes with elevation and distance inland. We present new data from coastal ice core sites including Mill Island off the coast of east Antarctica and the upper and lower Totten glacier to the east of Law Dome. Using this combined dataset we estimate the source strengths of sea salt aerosols, their partitioning and quantify the relationship with elevation and distance inland.
Curran, M. A.; van Ommen, T. D.; Moy, A. D.; Vance, T.; Wong, G. J.; Goodwin, I. D.; Domensino, B.
Dual overflows into the deep Sulu Sea
NASA Astrophysics Data System (ADS)
The Sulu Sea, isolated from the neighboring ocean below 570 m, is nearly isothermal below 1250 m but with a marked salinity increase with depth. The source of the deep Sulu Sea water has been attributed to South China Sea water overflowing the 570 m topographic sill of Panay Strait. However, the Panay overflow (estimated as 0.32 × 106 m3/sec) is an unlikely source for the saltier water Sulu Sea deep water. We propose that deep Sulu Sea ventilation is derived from the south, from the Sulawesi Sea through Sibutu Passage. Sulawesi Sea water between 245 to 527 m, is mixed and heaved over the Sibutu Passage 234 m sill by the energetic tidal environment. Oxygen concentrations within the deep Sulu Sea suggest that the Sulawesi overflow is 0.15 × 106 m3/sec, with a residence time of Sulu Sea deep water of 60 years. The deep tropical Sulu Sea has the unique distinction of being ventilated from two separate sources, whose ratio may fluctuate across a range of temporal scales, associated with regional thermocline depth changes.
Gordon, Arnold L.; Tessler, Zachary D.; Villanoy, Cesar
Creating Arctic Sea Ice Protected Areas?
NASA Astrophysics Data System (ADS)
As Arctic sea ice retreats and the Northwest Passage and Northern Sea Route open, the Arctic will experience more extensive human activity than it has ever encountered before. New development will put pressure on a system already struggling to adapt to a changing environment. In this analysis, locations are identified within the Arctic that could be protected from resource extraction, transportation and other development in order to create refuges and protect remnants of sea ice habitat, as the Arctic transitions to ice-free summer conditions. Arctic sea ice forms largely along the Siberian and Alaskan coasts and is advected across the North Pole towards Fram Strait, the Canadian Archipelago and the Barents Sea. In addition to the future loss of ice itself, contaminants entrained in sea ice in one part of the ocean can affect other regions as the ice drifts. Using observations and models of sea ice origins, trajectories and ages, we track sea ice from its origins towards marginal ice zones, mapping pathways and termination locations. Critical sea ice source areas and collection regions are identified with the goal of aiding in the protection of the remaining Arctic sea ice habitat for as long as possible.
Pfirman, S.; Hoff, K.; Temblay, B.; Fowler, C.
Multidecadal Signals in the Sea Level Budget
NASA Astrophysics Data System (ADS)
The detection and attribution of climate signals in sea level requires multi-decadal records of total sea level and its components with sufficient accuracy and coverage to distinguish climate change signals relative to natural variability. The current ocean observing system is capable of monitoring the components of the sea level rise budget for climatic signals. However, the detection times and constraints for climate signals in the sea level budget are not well understood. The sea level budget is closed when the sum of these independently measured components agrees with measurements of total sea level, indicating that the observations can be used to meaningfully explain the causes of sea level change. With cross-spectral analysis between total sea level and its components during 2005-2012, the relative contributions of each component can be assessed at different frequencies. Using an admittance analysis on Jason, GRACE, and Argo data, we demonstrate that the budget closes at all significant frequencies, including those in the intra-annual, annual, and interannual. The presence of interannual signals (e.g. PDO, ENSO) in sea level suggests that identifying and monitoring sea level variations associated with climate change will require very long records. The three nascent climate data records that are available with global coverage -- sea level (satellite altimetry 1993-), ocean mass (GRACE gravity mission 2002-), and steric height (the Argo array of hydrographic profiles 2005-) -- are too short for detection studies. We investigate climate signal detection times and constraints using a simulated sea level budget using reconstructed total sea level and multidecadal simple ocean data assimilations.
Leuliette, E. W.; Tamisiea, M. E.; Velicogna, I.; Rignot, E. J.; Carton, J.; Smith, W. H.
The expected impact of the "Peace Conduit" project (the Red Sea - Dead Sea pipeline) on the Dead Sea
The Dead Sea is a severely disturbed ecosystem, greatly damaged by anthropogenic intervention in its water balance. During\\u000a the 20th century, the Dead Sea level dropped by more than 25 meters, and presently (2003) it is at about 416 meters below\\u000a mean sea level. This negative water balance is mainly due to the diversion of water from the catchment area
Ittai Gavrieli; Amos Bein; Aharon Oren
Holocene sea level change along the coasts of China and South China Sea
NASA Astrophysics Data System (ADS)
This research reconstructed the Holocene sea-level history in China and South China Sea (between the equator and 40°N) by reviewing published relative sea-level and sediment records. The collected 14C dates of sea-level indicators were calibrated to calendar years before present. Details of the lithostratigraphy, micro-fossil evidence and sedimentary characteristics of the sediment records were used for quantifying the vertical relationship to local reference tidal level for each of the sea-level indicators. The corrected data were plotted to produce sea-level curves. The reconstructed sea-level curves uniformly confirm a phase of rapid sea-level rise before 8000 cal. yr BP and show marked spatial differences between latitudes. In the southern sector (southern South China Sea), relative sea level reached a highstand of c. 2 m around 5800 cal. yr BP. In the northern sector (Bohai Bay and the Yellow Sea), however, relative sea level continued to rise over the past 6000 years at a slow rate. This series of sea-level curves provide an opportunity to evaluate the effects of hydro-isostatic processes along this coast. In addition, localized tectonic movements can also be identified.
Sun, Yiying; Zong, Yongqiang
The suspended sediment concentration distribution in the Bohai Sea, Yellow Sea and East China Sea
NASA Astrophysics Data System (ADS)
The distribution of the suspended sediment concentration (SSC) in the Bohai Sea, Yellow Sea and East China Sea (BYECS) is studied based on the observed turbidity data and model simulation results. The observed turbidity results show that (i) the highest SSC is found in the coastal areas while in the outer shelf sea areas turbid water is much more difficult to observe, (ii) the surface layer SSC is much lower than the bottom layer SSC and (iii) the winter SSC is higher than the summer SSC. The Regional Ocean Modeling System (ROMS) is used to simulate the SSC distribution in the BYECS. A comparison between the modeled SSC and the observed SSC in the BYECS shows that the modeled SSC can reproduce the principal features of the SSC distribution in the BYECS. The dynamic mechanisms of the sediment erosion and transport processes are studied based on the modeled results. The horizontal distribution of the SSC in the BYECS is mainly determined by the current-wave induced bottom stress and the fine-grain sediment distribution. The current-induced bottom stress is much higher than the wave-induced bottom stress, which means the tidal currents play a more significant role in the sediment resuspension than the wind waves. The vertical mixing strength is studied based on the mixed layer depth and the turbulent kinetic energy distribution in the BYECS. The strong winter time vertical mixing, which is mainly caused by the strong wind stress and surface cooling, leads to high surface layer SSC in winter. High surface layer SSC in summer is restricted in the coastal areas.
Bian, Changwei; Jiang, Wensheng; Greatbatch, Richard J.; Ding, Hui
Weyl's Theory of Glaciation Supported by Isotopic Study of Norwegian Core K 11.
Oxygen-18 analyses of pelagic and benthic foraminifera from core K 11 indicate that during the last glaciation Norwegian Sea bottom waters were warmer than in modern times and had the same physical parameters (temperature, oxygen isotope ratio, and salinity) as the North Atlantic deep water. This result indicates that the glacial Norwegian Sea was not a sink for dense surface water, as it is now, and that during glacial times North Atlantic deep water invaded the deep Norwegian basin. PMID:17818162
Duplessy, J C; Chenouard, L; Vila, F
Methane in coastal sea water, sea ice, and bottom sediments, Beaufort Sea, Alaska
This report summarizes data acquired from 1990 to 1994 for the gas-hydrate portion of the USGS project 'Permafrost and gas hydrate as possible sources of methane' of the USGS Global Change and Climate History program. The objective of this project has been to test the hypothesis that gas hydrate deposits of the Beaufort Sea continental shelf are destabilized by the ~10?C temperature increase that has resulted from the Holocene transgression of the Arctic Ocean. To test this idea we have selected an area off the north coast of Alaska centered on Harrison Bay. We have measured the concentration of methane in surficial sediments, in the water column when ice is present and absent, and in seasonal sea ice. Our results show that more methane is present in the water when ice is present than when ice is absent, and that methane is also present within the ice itself, often at higher concentrations than in the water. Thus the Beaufort Sea shelf of Alaska is a seasonal source of methane. The primary source of this methane has not yet been defined, but gas hydrate is a reasonable candidate.
Lorenson, Thomas D.; Kvenvolden, Keith A.
Physics of the nucleon sea quark distributions
Sea quark distributions in the nucleon have naively been expected to be generated perturbatively by gluon splitting. In this case, there is no reason for the light quark and anti-quark sea distributions to be different. No asymmetries in the strange or heavy quark sea distributions are predicted in the improved parton model. However,recent experiments have called these naive expectations into question. A violation of the Gottfried sum rule has been measured in several experiments, suggesting that (bar u) < (bar d) in the proton. Additionally, other measurements, while not definitive, show that there may be an asymmetry in the strange and anti-strange quark sea distributions. These effects may require nonperturbative explanations. In this review we first discuss the perturbative aspects of the sea quark distributions. We then describe the experiments that could point to nonperturbative contributions to the nucleon sea. Current phenomenological models that could explain some of these effects are reviewed.
Vogt, R.
Tropical Atlantic influence on Amundsen Sea Circulation
NASA Astrophysics Data System (ADS)
Antarctic climate in winter is known to be influenced, among other factors, by changes in radiative forcing and remote Pacific climate variability, but none explain the observed sea ice trend or Peninsula warming. Looking to the North/Tropical Atlantic, a leading mode of Sea Surface Temperature (SST) variability, the Atlantic Multi-decadal Oscillation (AMO), has been overlooked. We show that AMO related SST anomalies, particularly in the Tropical Atlantic, induce a positive phase response in the Southern Annular Mode, strengthen the Amundsen Sea Low, project onto the observed dipole-like sea-ice distribution between the Ross and Amundsen Seas, and contribute to Antarctic Peninsula warming. Support for these findings comes from analysis of observational and reanalysis data, and is independently verified by atmospheric model simulations forced by specified SSTs. This study implies that the North/Tropical Atlantic is relevant for understanding changes in ocean circulation in the Amundsen Sea and hence ice shelf melt in that region.
Holland, D. M.; Li, X.; Gerber, E. P.
First biological measurements of deep-sea corals from the Red Sea
It is usually assumed that metabolic constraints restrict deep-sea corals to cold-water habitats, with 'deep-sea' and 'cold-water' corals often used as synonymous. Here we report on the first measurements of biological characters of deep-sea corals from the central Red Sea, where they occur at temperatures exceeding 20°C in highly oligotrophic and oxygen-limited waters. Low respiration rates, low calcification rates, and minimized tissue cover indicate that a reduced metabolism is one of the key adaptations to prevailing environmental conditions. We investigated four sites and encountered six species of which at least two appear to be undescribed. One species is previously reported from the Red Sea but occurs in deep cold waters outside the Red Sea raising interesting questions about presumed environmental constraints for other deep-sea corals. Our findings suggest that the present understanding of deep-sea coral persistence and resilience needs to be revisited.
Roder, C.; Berumen, M. L.; Bouwmeester, J.; Papathanassiou, E.; Al-Suwailem, A.; Voolstra, C. R.
Infrared image synthesis for the wind-ruffled sea
The sea surface as an important form of background usually plays a decisive role in sea applications. Real backgrounds are expensive while sea simulation can generate realistic images under various conditions. In this paper, a physics based model of infrared image synthesis for wind-ruffled sea is proposed. It consists of an integrated process based on oceanographic models of sea waves
Xun Wang; Zhaoyi Jiang; Yun Ling; Jianqiu Jin
The role of sea ice dynamics in global climate change
NASA Technical Reports Server (NTRS)
The topics covered include the following: general characteristics of sea ice drift; sea ice rheology; ice thickness distribution; sea ice thermodynamic models; equilibrium thermodynamic models; effect of internal brine pockets and snow cover; model simulations of Arctic Sea ice; and sensitivity of sea ice models to climate change.
Hibler, William D., III
Recent state of the Aral sea from regular satellite observations
The Aral Sea disaster is one of the most significant examples of ecological catastrophe caused by mismanagement of water resources. Aral sea level dropped on 22 meters for the last 35 years. The sea separated in to two independent parts , the Large Sea(Southern) and the Small Sea (Northern), loosing more than 90% of its original water masses. After the
S. Stanichny; A. Davidov; S. Djenidi; U. Horstmann; R. Stanichnaya; D. Soloviev
Sea water desalination system, McMurdo
Title : Sea water desalination system, McMurdo Type : Antarctic EAM NSF Org: OD / OPP Date : May 18, 1993 File : opp93104 INITIAL ENVIRONMENTAL EVALUATION REPLACEMENT OF THE SEA WATER DESALINATION SYSTEM, MCMURDO STATION, ANTARCTICA National Science Foundation Office of Polar Programs Washington, DC May 18, 1993 1. INTRODUCTION The U.S. Antarctic Program (USAP) is proposing to replace the Sea Water Desalination System at McMurdo Station, Antarctica, during the 1993-1994 season.
Oscillating Quaternary water levels of the Marmara Sea and vigorous outflow into the Aegean Sea from the Marmara Sea–Black Sea drainage corridor
Detailed interpretation of single-channel air-gun and deep-tow boomer profiles demonstrates that the Marmara Sea, Turkey, experienced small-amplitude (?70 m) fluctuations in sea level during the later Quaternary, limited in magnitude by the sill depth of the Strait of Dardanelles. Moderate subsidence along the southern shelf and Quaternary glacio-eustatic sea-level variations created several stacked deltaic successions, separated by major shelf-crossing unconformities,
A. E Aksu; R. N Hiscott; D Ya?ar
? Abstract Decades of seabed mapping, reflection profiling, and seabed sampling reveal that throughout,the past two million years the Black Sea was predominantly,a freshwater lake interrupted only briefly by saltwater invasions coincident with global sea level highstand. When,the exterior ocean lay below,the relatively shallow sill of the Bosporus outlet, the Black Sea operated in two modes. As in the neighboring
William B. F. Ryan; Candace O. Major; Gilles Lericolais; Steven L. Goldstein
Aplanktonic zones in the Red Sea
We use micropalaeontological and stable isotope results for a series of cores from north to south through the Red Sea, to assess temporal and spatial patterns of change in planktonic foraminiferal faunas leading up to the remarkable full-glacial Red Sea aplanktonic zones. Aplanktonic zones reflect salinities in the Red Sea in excess of the lethal 49p.s.u. limit, caused by reduced
M. Fenton; S. Geiselhart; E. J. Rohling; Ch. Hemleben
Scientific reticence and sea level rise
NASA Astrophysics Data System (ADS)
I suggest that a 'scientific reticence' is inhibiting the communication of a threat of a potentially large sea level rise. Delay is dangerous because of system inertias that could create a situation with future sea level changes out of our control. I argue for calling together a panel of scientific leaders to hear evidence and issue a prompt plain-written report on current understanding of the sea level change issue.
Hansen, J. E.
Hubbs-Sea World Research Institute
NSDL National Science Digital Library
Describes the Research Institute's use of science in developing solutions for conservation challenges facing marine ecosystems and species. Overviews of research projects in ecology, physiology, bioacoustics and aquaculture. Species studied include: marine mammals, sea turtles, whale shark, white sea bass and others. Explains how satellite tracking technology is used to study survival needs of endangered species (leatherback sea turtle, Hawaiian monk seal). Outlines educational objectives and contributions, news and events. Appropriate for grades 8 and up.
Sea ice-albedo climate feedback mechanism
The sea ice-albedo feedback mechanism over the Arctic Ocean multiyear sea ice is investigated by conducting a series of experiments using several one-dimensional models of the coupled sea ice-atmosphere system. In its simplest form, ice-albedo feedback is thought to be associated with a decrease in the areal cover of snow and ice and a corresponding increase in the surface temperature,
J. L. Schramm; J. A. Curry; Elizabeth E. Ebert
Correlating the shallow and the deep 3D-structure of the Barents Sea/ Kara Sea
NASA Astrophysics Data System (ADS)
The Barents Sea and Kara Sea continental shelf region is located in the northern European Arctic. The crustal configuration of the Barents Sea/Kara Sea region exhibits a complex architecture of the sedimentary cover which implies the influence of diverse causative geological processes. The narrow and deep basins of the southwestern Barents Sea characterise rift basins which have been filled with thick sediments predominantly Mesozoic in age. In contrast, the eastern Barents Sea and the southern Kara Sea are marked by a wide and deep basin architecture which indicates basin formation mechanisms apart from rifting. There, the sedimentary succession yields Paleozoic and Mesozoic sediments. Cenozoic deposits are restricted to the southwesternmost parts of the Barents Sea and the oceanic domain. The lack of sediments on the shelf is attributed to strong Pleistocene uplift, subsequent erosion and recurring ice sheet coverage of the Barents Sea/Kara Sea region. The modelled area covers about 5 million km² with a maximum longitudinal and latitudinal extent of 2180 and 2400 km, respectively, and comprises regions beyond the Barents Sea and Kara Sea such as parts of Greenland, Fennoscandia and western Siberia. This study presents the lithospheric density configuration below the greater Barents Sea/ Kara Sea region. Thereby, five sedimentary megasequences are differentiated across the entire study area. Each unit is modelled with matrix densities and depth dependent porosities to calculate the bulk densities. The respective compaction curves reflect that strong late Cenozoic erosion and ice sheet coverage removed particularly less dense sediments on Svalbard and Novaya Zemlya, while in the eastern Barents Sea and the southern Kara Sea erosion was less effective. Thus, the obtained sedimentary bulk densities vary laterally distinctively. The density setup of the subsedimentary lithosphere beneath the Barents shelf is defined by a high-resolution, velocity-converted density grid. This dataset is tested the first time against gravity to further constrain the 3D density model. Interestingly, region that experienced weaker Cenozoic erosion are underlain by a heavier mantle density composition.
Klitzke, Peter; Faleide, Jan Inge; Sippel, Judith; Scheck-Wenderoth, Magdalena
Global sea level linked to global temperature
We propose a simple relationship linking global sea-level variations on time scales of decades to centuries to global mean temperature. This relationship is tested on synthetic data from a global climate model for the past millennium and the next century. When applied to observed data of sea level and temperature for 1880–2000, and taking into account known anthropogenic hydrologic contributions to sea level, the correlation is >0.99, explaining 98% of the variance. For future global temperature scenarios of the Intergovernmental Panel on Climate Change's Fourth Assessment Report, the relationship projects a sea-level rise ranging from 75 to 190 cm for the period 1990–2100.
Vermeer, Martin; Rahmstorf, Stefan
Permanent Service for Mean Sea Level
NSDL National Science Digital Library
The Permanent Service for Mean Sea Level (PSMSL), hosted by the Proudman Oceanographic Laboratory (POL), is the global data bank for long term sea level change information from tide gauges. The PSMSL data set is the main source of information on long term changes in global sea level during the last two centuries. This site contains data sets, and information on other services such as vertical land movements and air pressure. There are answers to frequently asked questions about sea level changes, packets on data use available, annual reports, and other contacts for more information.
... Sea Ice Camp) To: Polar Ocean Sciences Program Manager, DPP Ocean Projects Manager, DPP Field ... 17, 1991. National Science Foundation. 1991. Ocean Projects Manager, DPP, Memorandum: Environmental ...
A Multi-Disciplinary Sea Ice Ontology
NASA Astrophysics Data System (ADS)
Sea ice is a central element of the Arctic system and a strong indicator of high-latitude climate change. In addition to the many scientific disciplines in which sea ice is of importance, the domains of transportation, defense, natural resources and human settlements all have interests in and contribute to the body of knowledge regarding sea ice. To help advance the interdisciplinary understanding and usability of sea ice data we have developed a preliminary sea ice ontology. This effort began with a workshop in which sea ice modelers, field researchers, remote sensing scientists and operational forecasters described the facets of sea ice from the perspective of their respective disciplines. We will describe the features of this ontology and highlight some of the challenges we encountered in building it. We will also describe our plans to incorporate indigenous sea ice knowledge, map some existing sea ice data sets using the ontology, and to link the ontology to relevant marine, polar, atmospheric, and global ontologies and semantic services.
Khalsa, S. S.; Parsons, M. A.; Duerr, R. E.; Pulsifer, P. L.; McGuinness, D. L.; Fox, P. A.; McCusker, J.
Traditional chinese medicine--sea urchin.
The sea urchin is an ancient, common, seafloor-dwelling marine invertebrate that belongs to the phylum Echinodermata. There are multiple species of sea urchin with resources that are widely distributed in China, where they were used in ancient times as Traditional Chinese Medicine for treating a variety of diseases. At present, it is known that the shell, spine and gonad of the sea urchin have many medicinal values determined through modern research. In this paper, we summarized the major chemical constituents and medicinal value of the sea urchin. PMID:24873818
Shang, Xiao-Hui; Liu, Xiao-Yu; Zhang, Jian-Peng; Gao, Yun; Jiao, Bing-Hua; Zheng, Heng; Lu, Xiao-Ling
Extreme 2008: A Deep Sea Adventure
NSDL National Science Digital Library
This website, designed for K-12 teachers and students, offers materials and activities based on the "Extreme 2008: A Deep Sea Adventure" mission to explore deep-sea hydrothermal vents. Students can step into the shoes of deep-sea scientists as they follow the expedition and listen to recordings of student communications with the researchers via e-mail and telephone calls placed directly to Alvin, a research submersible, as it made its way deep into the Pacific. Topics include sea creatures, geology, plate tectonics, and chemistry of the deep ocean. Video clips are also provided to help students visualize the underwater experience.
A biomarker-based reconstruction of sea ice conditions for the Barents Sea in recent centuries
Variations in sea ice occurrence for the Barents Sea since c. AD 1700 have been determined by analysis of the abundance of the sea ice biomarker IP25 in three marine sediment box cores obtained from locations in the north, southeast and southwest parts of the region. Depth\\/age models for each core were established using excess 210Pb activity profiles. Comparisons between
Lindsay L. Vare; Guillaume Massé; Simon T. Belt
Late and Postglacial Sea-Level Change and Paleoenvironments in the Oder Estuary, Southern Baltic Sea
Knowledge of sea-level change in the southern Baltic Sea region is important for understanding the variations in late Pleistocene and Holocene sea-level change across northern Europe. These variations are a consequence of the response of the Earth's crust to the deglaciation of Fennoscandia and of the water added to the oceans from the melting of all Pleistocene ice sheets. The
Anne Müller
SEAS Classroom to Sea Labs: New Directions for Ridge 2000 Communitywide Education Outreach
Lessons learned from the two year SEAS pilot program emphasize that student participation in deep-sea research is an important motivator in student learning. Further, SEAS students experience a paradigm shift in understanding evidence-based reasoning and the process of scientific discovery. At the same time, we have learned that fostering authentic student investigations within the confines of the academic year is
L. Goehring
Polar Seas Oceanography: An Integrated Case Study of the Kara Sea
What strikes first when browsing through this book is that the main title is misleading. Polar Seas Oceanography is, first of all, a book on ``an integrated case study of the Kara Sea,'' as the subtitle says. For readers who are interested more generally in polar oceanography, the book is probably the wrong choice. The Kara Sea is a rather
Ingo Harms
A numerical experiment on the sedimentation processes in the Yellow Sea and the East China Sea
Sedimentation processes of suspended matter supplied from the Huanghe (Yellow River) and the Changjiang are investigated with the use of a three-dimensional numerical model of the Yellow Sea and the East China Sea which includes the tidal current, residual flow and wind waves. Suspended matter supplied from the Huanghe mainly deposits in the Bohai Sea and that from the old
Tetsuo Yanagi; Koh-ichi Inoue
Temporal and spatial variations of sea surface temperature in the East China Sea
Sea surface temperature of the East China Sea (ECS) were analyzed using the NOAA\\/AVHRR SST images. These satellite images reveal surface features of ECS including mainly the Kuroshio Current, Kuroshio Branch Current, Taiwan Warm Current, China coastal water, Changjiang diluted water and Yellow Sea mixed cold water. The SST of ECS ranges from 27 to 29°C in summer; some cold
Chente Tseng; Chiyuan Lin; Shihchin Chen; Chungzen Shyu
The Barents and Chukchi Seas: Comparison of two Arctic shelf ecosystems
NASA Astrophysics Data System (ADS)
This paper compares and contrasts the ecosystems of the Barents and Chukchi Seas. Despite their similarity in a number of features, the Barents Sea supports a vast biomass of commercially important fish, but the Chukchi does not. Here we examine a number of aspects of these two seas to ascertain how they are similar and how they differ. We then indentify processes and mechanisms that may be responsible for their similarities and differences. Both the Barents and Chukchi Seas are high latitude, seasonally ice covered, Arctic shelf-seas. Both have strongly advective regimes, and receive water from the south. Water entering the Barents comes from the deep, ice-free and "warm" Norwegian Sea, and contains not only heat, but also a rich supply of zooplankton that supports larval fish in spring. In contrast, Bering Sea water entering the Chukchi in spring and early summer is cold. In spring, this Bering Sea water is depleted of large, lipid-rich zooplankton, thus likely resulting in a relatively low availability of zooplankton for fish. Although primary production on average is similar in the two seas, fish biomass density is an order of magnitude greater in the Barents than in the Chukchi Sea. The Barents Sea supports immense fisheries, whereas the Chukchi Sea does not. The density of cetaceans in the Barents Sea is about double that in the Chukchi Sea, as is the density of nesting seabirds, whereas, the density of pinnipeds in the Chukchi is about double that in the Barents Sea. In the Chukchi Sea, export of carbon to the benthos and benthic biomass may be greater. We hypothesize that the difference in fish abundance in the two seas is driven by differences in the heat and plankton advected into them, and the amount of primary production consumed in the upper water column. However, we suggest that the critical difference between the Chukchi and Barents Seas is the pre-cooled water entering the Chukchi Sea from the south. This cold water, and the winter mixing of the Chukchi Sea as it becomes ice covered, result in water temperatures below the physiological limits of the commercially valuable fish that thrive in the southeastern Bering Sea. If climate change warms the Barents Sea, thereby increasing the open water area via reducing ice cover, productivity at most trophic levels is likely to increase. In the Chukchi, warming should also reduce sea ice cover, permitting a longer production season. However, the shallow northern Bering and Chukchi Seas are expected to continue to be ice-covered in winter, so water there will continue to be cold in winter and spring, and is likely to continue to be a barrier to the movement of temperate fish into the Chukchi Sea. Thus, it is unlikely that large populations of boreal fish species will become established in this Arctic marginal sea.
Hunt, George L.; Blanchard, Arny L.; Boveng, Peter; Dalpadado, Padmini; Drinkwater, Kenneth F.; Eisner, Lisa; Hopcroft, Russ R.; Kovacs, Kit M.; Norcross, Brenda L.; Renaud, Paul; Reigstad, Marit; Renner, Martin; Skjoldal, Hein Rune; Whitehouse, Andy; Woodgate, Rebecca A.
NASA Astrophysics Data System (ADS)
Prior to the studies reviewed here, only lymphocystis and skeletal deformities of a variety of fish species and certain diseases of eel were known to occur in the German Bight (North Sea). From 1977 until now, 9 externally visible lesions on North Sea fishes were observed; in addition to those mentioned before, they comprise: fin rot, ulcerations, epidermal papilloma, hyperplasia, pseudobranchial tumour, eye diseases and gill swellings. With the exception of information on changes in frequencies of vertebral deformities of herring from the 1950's to the 1970's, there are no long-term data characterizing changes in frequencies of the diseases under study. For pseudobranchial tumours of cod and epidermal papilloma of dab, information is provided on occurrence and abundance. The distribution pattern of cod afflicted with pseudobranchial tumours is strongly influenced by the migratory behaviour of the fish. Epidermal papillomas of dab were more frequently found at stations within the inner German Bight than in neighbouring areas. The Bight is used for dumping of wastes from titaniumdioxide production. Further disease hot spots are areas off the Humber estuary and the British coast. Analysis of chromium in dab from the German Bight revealed elevated concentrations in epidermal tissues of specimens from the dumping area compared with that found in dab from neighbouring localities. Particulate iron was demonstrated to occur in mucous cells of dab from the dumping area. From increased levels of heavy metals with cancerogenic potential in sensitive target tissues and from increased prevalences of diseased fish in the dumping area it is concluded that these phenomena are possibly causally linked. In the vicinity of the Humber estuary high disease rates were encountered and areas with high prevalences of dab afflicted with epidermal papilloma extended over regions shown to be transport routes for persistent pollutants such as radioactive materials. It is therefore suggested that the long-range distribution of fish diseases in the southern North Sea might reflect the long-range transport of persistent pollutants.
Dethlefsen, V.
Advanced deep sea diving equipment
NASA Technical Reports Server (NTRS)
Design requirements are generated for a deep sea heavy duty diving system to equip salvage divers with equipment and tools that permit work of the same quality and in times approaching that done on the surface. The system consists of a helmet, a recirculator for removing carbon dioxide, and the diver's dress. The diver controls the inlet flow by the recirculatory control valve and is able to change closed cycle operation to open cycle if malfunction occurs. Proper function of the scrubber in the recirculator minimizes temperature and humidity effects as it filters the returning air.
Danesi, W. A.
Dr. Rachel Obbard and her research group from Dartmouth College traveled to the Antarctic to collect samples of sea ice. Next stop: the GeoSoilEnviroCARS x-ray beamline at the Advanced Photon Source at Argonne National Laboratory in Illinois. This U.S. Department of Energy Office of Science synchrotron x-ray research facility gave the Obbard team the frontier scientific tools they needed to study the path bromide takes as it travels from the ocean to the atmosphere.
Dr. Rachel Obbard
Concentrations of noble gases in samples of sea water obtained at depths to 3437 meters from a Pacific Ocean station were measured by mass spectrometry. An excess of helium, in relation to concentrations of the other noble gases, is attributed to influx of atoms of this gas from the sediments where it is produced by the natural radioactive decay of members of the uranium and thorium series. On the basis of a steady-state model, the escape of helium from the earth is calculated at 6.4 x 10(13) atoms per square centimeter per year. PMID:17832398
Bieri, R; Koide, M; Goldberg, E D
Solar distillation of sea water
Indian coastal and fishing villages suffer from scarcity of potable water. Solar distillation could provide a solution to this problem by adopting the following criteria: (1) Integration of distillation and storage systems with the house design. (2) Public supply of sea water and a public drain pipe system to periodically drain away the concentrated brine. (3) Harvest and store rain water to tide over cloudy rainy periods. In India there has been a thrust towards centralized non-conventional energy systems. Decentralized non-conventional energy devices and centralized service support units may offer a better solution. 1 fig.
Subramanyam, S. (Kakatiya Institute of Technology and Science, Warangal (India))
Climate and sea ice variability in the SW Labrador Sea during the late Holocene
NASA Astrophysics Data System (ADS)
The recent rapid decline in Arctic sea ice cover has increased the need to improve the accuracy of the sea ice components in climate models and to provide detailed long-term sea ice records based on proxy data. Recently, the highly branched isoprenoid IP25 has emerged as a potential sea ice specific proxy for past sea ice cover, found in marine sediments underlying seasonal sea ice. We tested the reliability of this biomarker against observational sea ice data off Newfoundland (SW Labrador Sea), where box cores covering the last ca. 100-150 years were collected. Based on the results, IP25 proved to be a robust and reliable proxy for reconstructing variability in past sea ice concentrations in the area. After having successfully validated the proxy in the SW Labrador Sea, we further analysed IP25 from a sediment core NE of Newfoundland covering the last ca. 5000 years, providing the southernmost multi-millennial record of this proxy to date. Based on this record and on diatom and dinoflagellate cyst data and alkenone-based sea surface temperatures (SSTs) from the same core, we reconstructed climatic conditions in and Arctic sea ice export to the SW Labrador Sea area: Alkenone-based SSTs show a clear albeit variable decline after the Holocene Climate Optimum, while at the same time diatom and dinoflagellate cyst data suggest decreased melt water export from the Arctic. The IP25 record reveals increased sea ice export from the Baffin and Hudson Bays starting ca 1500 yr cal. BP, accelerating ca. 800 yr cal. BP and culminating at the height of the Little Ice Age. Sea ice export during the last century is comparable to the export during the Medieval Climate Anomaly.
Weckström, Kaarina; Massé, Guillaume; Collins, Lewis; Sicre, Marie-Alexandrine; Bouloubassi, Ioanna; Seidenkrantz, Marit-Solveig; Olsen, Jesper; Kuijpers, Antoon
Indian Ocean Rossby Waves Deteced in HYCOM Sea Surface Salinity.
National Technical Information Service (NTIS)
Rossby waves have been well identified in satellite derived sea surface height (SSH), sea surface temperature (SST) and ocean color observations. Studies of Rossby waves have yet to include sea surface salinity (SSS) as a parameter, largely because presen...
B. Subrahmanyam D. Heffner J. Shriver
50 CFR 648.143 - Black sea bass Accountability Measures.
Code of Federal Regulations, 2013 CFR
...12 2013-10-01 2013-10-01 false Black sea bass Accountability Measures. 648.143 ...NORTHEASTERN UNITED STATES Management Measures for the Black Sea Bass Fishery § 648.143 Black sea bass Accountability Measures. (a)...
50 CFR 648.142 - Black sea bass specifications.
Code of Federal Regulations, 2013 CFR
...12 2013-10-01 2013-10-01 false Black sea bass specifications. 648.142 Section 648...NORTHEASTERN UNITED STATES Management Measures for the Black Sea Bass Fishery § 648.142 Black sea bass specifications. (a) Commercial...
50 CFR 648.57 - Sea scallop area rotation program.
Code of Federal Regulations, 2010 CFR
...2009-10-01 2009-10-01 false Sea scallop area rotation program. 648.57 Section...STATES Management Measures for the Atlantic Sea Scallop Fishery § 648.57 Sea scallop area rotation program. An area rotation...
50 CFR 648.57 - Sea scallop area rotation program.
Code of Federal Regulations, 2010 CFR
...2010-10-01 2010-10-01 false Sea scallop area rotation program. 648.57 Section...STATES Management Measures for the Atlantic Sea Scallop Fishery § 648.57 Sea scallop area rotation program. An area rotation...
Observations of Mediterranean Flow into the Black Sea.
National Technical Information Service (NTIS)
Mediterranean Sea water inflow into the Black Sea is investigated using acoustic and oceanographic data obtained in the Black Sea exit region. The path of Mediterranean water and the resulting spreading on the continental shelf is observed with SWATH bott...
D. DiIorio H. Yuce
Biogeochemistry of the Kem' River estuary, White Sea (Russia)
The biogeochemistry of the river-sea interface was studied in the Kem' River (the largest river flowing to the White Sea from Karelian coast) estuary and adjacent area of the White Sea onboard the RV \\
V. R. Shevchenko; Y. S. Dolotov; N. N. Filatov; T. N. Alexeeva; A. S. Filippov; E.-M. Nöthig; A. N. Novigatsky; L. A. Pautova; A. V. Platonov; N. V. Politova; T. N. Rat'kova; R. Stein
Remote Sensing of Sea Ice in the Northern Sea Route: Studies and Applications
NASA Astrophysics Data System (ADS)
Given the rapid changes that are under way in Arctic sea ice extent, Remote Sensing of Sea Ice in the Northern Sea Route is a timely work. The Northern Sea Route (NSR), along the Arctic coast of Russia, has a long history, dating back to 1932, when the Soviet Union established the NSR administration to develop hydrometeorological services. Shipping along the sea route peaked in the 1980s, but there is renewed interest associated with a lengthening ice-free season and mineral exploitation. Since July 1991, the NSR has been open to all merchant vessels.
Barry, Roger G.
Erabutoxins a and b are neurotoxins isolated from venom of a sea snake Laticauda semifasciata (erabu-umihebi). Amino acid sequences of the toxins indicated that the toxins are members of a superfamily consisting of short and long neurotoxins and cytotoxins found in sea snakes and terrestrial snakes. The short neurotoxins to which erabutoxins belong act by blocking the nicotinic acetylcholine receptor on the post synaptic membrane in a manner similar to that of curare. X-ray crystallography and NMR analyses showed that the toxins have a three-finger structure, in which three fingers made of three loops emerging from a dense core make a gently concave surface of the protein. The sequence comparison and the location of essential residues on the protein suggested the mechanism of binding of the toxin to the acetylcholine receptor. Classification of snakes by means of sequence comparison and that based on different morphological features were inconsistent, which led the authors to propose a hypothesis "Evolution without divergence." PMID:21422738
Tamiya, Nobuo; Yagi, Tatsuhiko
Erabutoxins a and b are neurotoxins isolated from venom of a sea snake Laticauda semifasciata (erabu-umihebi). Amino acid sequences of the toxins indicated that the toxins are members of a superfamily consisting of short and long neurotoxins and cytotoxins found in sea snakes and terrestrial snakes. The short neurotoxins to which erabutoxins belong act by blocking the nicotinic acetylcholine receptor on the post synaptic membrane in a manner similar to that of curare. X-ray crystallography and NMR analyses showed that the toxins have a three-finger structure, in which three fingers made of three loops emerging from a dense core make a gently concave surface of the protein. The sequence comparison and the location of essential residues on the protein suggested the mechanism of binding of the toxin to the acetylcholine receptor. Classification of snakes by means of sequence comparison and that based on different morphological features were inconsistent, which led the authors to propose a hypothesis "Evolution without divergence."
TAMIYA, Nobuo; YAGI, Tatsuhiko
NSDL National Science Digital Library
This video is the second of a three-video series in the Sea Change project, which follows the work of Dr. Maureen Raymo, paleogeologist at Columbia University's Lamont-Doherty Earth Observatory, who travels with fellow researchers to Australia in search of evidence of sea level that was once higher than it is today.
Grossman, Daniel; Change, Sea
Sea Change Part 1: In the Field
NSDL National Science Digital Library
This video is the first of a three-video series from the Sea Change project. It features the field work of scientists from the US and Australia looking for evidence of sea level rise during the Pliocene era when Earth was (on average) about 2 to 3 degrees Celsius hotter than it is today.
Grossman, Daniel; Pliomax, Sea C.
Sea Change Part III: Interpreting the Results
NSDL National Science Digital Library
This video is the third in a three-part series by the Sea Change project, about scientists' search for Pleiocene beaches in Australia and elsewhere to establish sea level height during Earth's most recent previous warm period. This segment features the research of Jerry Mitrovica, Harvard geophysicist.
Grossman, Daniel
Searching the Ocean for Deep Sea Vents
NSDL National Science Digital Library
This Web-based slide show walks students through the painstaking and difficult search for deep sea vents. In pictures and text, it provides an overview of the subject explaining the process whereby the location of deep sea vents can be discovered from the surface using indirect methods.
Wind Speed Variability over the Marmara Sea.
National Technical Information Service (NTIS)
Between 2000 and 2006, wind speed measurements were collected over the Marmara Sea by the SeaWinds scatterometer on the QuikSCAT satellite at a spatial resolution of 0.25 x 0.25 degrees. Relatively small interannual variability was noted in monthly mean w...
A. B. Kara A. J. Wallcraft E. Jarosz M. Bourassa
Mesoscale Eddies in the Solomon Sea
NASA Astrophysics Data System (ADS)
Water mass transformation in the strong equatorward flows through the Solomon Sea influences the properties of the Equatorial Undercurrent and subsequent cold tongue upwelling. High eddy activity in the interior Solomon Sea seen in altimetric sea surface height (SSH) and in several models may provide a mechanism for these transformations. We investigate these effects using a mesoscale (4-km resolution) sigma-coordinate (ROMS) model of the Solomon Sea nested in a basin solution, forced by a repeating seasonal cycle, and evaluated against observational data. The model generates a vigorous upper layer eddy field; some of these are apparently shed as the New Guinea Coastal Undercurrent threads through the complex topography of the region, others are independent of the strong western boundary current. We diagnose the scales and vertical structure of the eddies in different parts of the Solomon Sea to illuminate their generation processes and propagation characteristics, and compare these to observed eddy statistics. Hypotheses tested are that the Solomon Sea mesoscale eddies are generated locally by baroclinic instability, that the eddies are shed as the South Equatorial Current passes around and through the Solomon Island chain, that eddies are generated by the New Guinea Coastal Undercurrent, or that eddies occurring outside of the Solomon Sea propagate into the Solomon Sea. These different mechanisms have different implications for the resulting mixing and property fluxes. They also provide different interpretations for SSH signals observed from satellites (e.g., that will be observed by the upcoming SWOT satellite).
Hristova, H. G.; Kessler, W. S.; McWilliams, J. C.; Molemaker, M. J.
Scientific reticence and sea level rise
I suggest that a 'scientific reticence' is inhibiting the communication of a threat of a potentially large sea level rise. Delay is dangerous because of system inertias that could create a situation with future sea level changes out of our control. I argue for calling together a panel of scientific leaders to hear evidence and issue a prompt plain-written report
J. E. Hansen
Monitoring and Control of Sea Water Composition.
National Technical Information Service (NTIS)
This report describes the work carried out in the study and preliminary design of a Sea Water Simulator. The purpose of the device is to approximate for various locales and depths, the sea water chemistry represented by eight chemical parameters: salinity...
H. C. Edgington
POLSSS: policy making for sea shipping safety
After The Netherlands Ministry of Transport, Public Works and Water Management published the progress report "Vessel Traffic Management on the North Sea" (1997), a need remained for policy refinement and extension of scope: (1) determination of the most appropriate mix of traffic management instruments; (2) inclusion of inland waters for sea-going ships; (3) specific attention for risk analysis of maritime
W van Urk; W. A de Vries
More on Sea Turtles and Seaweed
ERIC Educational Resources Information Center
"Sea turtle" and "seaweed"--otherwise known as "returnee from abroad" and "unemployed from abroad," respectively-- are a pair of popular new terms that are innately connected. In this article, the author discusses the common plight faced by "sea turtles" and "seaweeds" who returned from abroad to work in China. The author describes the experiences…
Xin, Tian
The application of ERTS imagery to monitoring Arctic sea ice. [mapping ice in Bering Sea, Beaufort Sea, Canadian Archipelago, and Greenland Sea
NASA Technical Reports Server (NTRS)
The author has identified the following significant results. Because of the effect of sea ice on the heat balance of the Arctic and because of the expanding economic interest in arctic oil and minerals, extensive monitoring and further study of sea ice is required. The application of ERTS data for mapping ice is evaluated for several arctic areas, including the Bering Sea, the eastern Beaufort Sea, parts of the Canadian Archipelago, and the Greenland Sea. Interpretive techniques are discussed, and the scales and types of ice features that can be detected are described. For the Bering Sea, a sample of ERTS-1 imagery is compared with visual ice reports and aerial photography from the NASA CV-990 aircraft. The results of the investigation demonstrate that ERTS-1 imagery has substantial practical application for monitoring arctic sea ice. Ice features as small as 80-100 m in width can be detected, and the combined use of the visible and near-IR imagery is a powerful tool for identifying ice types. Sequential ERTS-1 observations at high latitudes enable ice deformations and movements to be mapped. Ice conditions in the Bering Sea during early March depicted in ERTS-1 images are in close agreement with aerial ice observations and photographs.
Barnes, J. C. (principal investigator); Bowley, C. J.
Optical properties of the Kara Sea
This study was motivated by the need to understand dispersion processes which affect the redistribution of nuclear wastes in the Arctic from dump sites in the Kara Sea and in the rivers which flow into the Kara Sea. We focus on vertical profiles of light beam transmission and fluorometry made over the delta region fronting the Ob and Yenisey Rivers
Donald R. Johnson; Vernon Asper; Thomas McClimans; Alan Weidemann
Naval UAV Programs: Sea Based UAV's.
National Technical Information Service (NTIS)
The purpose of this document is to state the importance of having an evolving sea based UAV program to aid in the development of successive sea based UAV systems. The Pioneer use on hoard LPDs and changing requirements helped shape the VTUAV development. ...
L. D. Whitmer
Seismogeodynamics of the Caspian Sea Region
Results of studies of fluctuations in seismic regime of the Caspian Sea and adjacent area are ana- lyzed in order to reveal the correlation of anomalous variations in the sea level with seismicity of the region. The inferred regularities indicate that these phenomena have a common origin. A seismogeodynamic model of the region under consideration is discussed.
Sea Energy Conversion: Problems and Possibilities
Nowadays, policies are being developed in many countries in order to decrease their greenhouse gases emissions. While in this area some technologies are widely installed (wind and solar energy), other ones, like the sea energy, could get an important role in the medium and long term. That is why the most relevant technologies associated to the sea energy conversion are
G. Buigues; I. Zamora; A. J. Mazón; V. Valverde; F. J. Pérez
NASA Technical Reports Server (NTRS)
On July 22, 2001, SeaWiFS imaged a yellowish-brown plume emanating from the Mt. Etna volcano and stretching over 600 kilometers southeastward across the Mediterranean towards Libya. Credit: Credit line for all images: Provided by the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE
Strategic Science Plan: Salton Sea Restoration Project.
National Technical Information Service (NTIS)
The Salton Sea is an ecosystem in peril. Its prehistory consists of a series of intermittent lakes dependent on infrequent flooding of the Colorado River, while the modern Salton Sea originated from the desire to harness the flow of the Colorado River for...
Geothermal Development and the Salton Sea.
National Technical Information Service (NTIS)
The purpose of this study is to examine the relationship of the Salton Sea, a key element of the Imperial Valley water system, to potential geothermal development. The most damaging effect would be the direct flow of geothermal brines into the Sea in larg...
M. Goldsmith
Metagenomic sequencing of two salton sea microbiomes.
The Salton Sea is the largest inland body of water in California, with salinities ranging from brackish freshwater to hypersaline. The lake experiences high nutrient input, and its surface water is exposed to temperatures up to 40°C. Here, we report the community profiles associated with surface water from the Salton Sea. PMID:24459270
Hawley, Erik R; Schackwitz, Wendy; Hess, Matthias
Oceanography: Detecting sea-level rise
NASA Astrophysics Data System (ADS)
Over short periods of time, it can be difficult to isolate sea-level increase in observations as it is hidden by natural shifts in rainfall quantities over ocean and land, which cause temporary drops in the global sea-level curve. Now research shows how to detect the signal, even in short records, by estimating these variations.
Boening, Carmen
NSDL National Science Digital Library
Animation of the Pacific Ocean sea surface height from 1993-2011. Data gathered by multiple NASA satellite missions (TOPEX/Poseidon, Jason-1, and Jason 2). Animation shows view of Pacific Ocean and simultaneously graphs global average sea surface height data.
The changing Mediterranean Sea — a sensitive ecosystem?
I was asked to present a keynote paper on the socio-economic aspects of oceanographic research in the Mediterranean Sea in the Session on From Oceanographic Science to Policy at the International Conference on Progress in Oceanography of the Mediterranean Sea, Rome November 1997. The session was unique in that it included papers from oceanographers, social scientists and economists. For this
Carol M Turley
Tritium level along Romanian Black Sea Coast
Establishing the tritium level along the Romanian Black Sea Coast, after 10 years of exploitation of the nuclear power plant from Cernavoda, is a first step in evaluating its impact on the Black Sea ecosystem. The monitoring program consists of tritium activity concentration measurement in sea water and precipitation from Black Sea Coast between April 2005 and April 2006. The sampling points were spread over the Danube-Black Sea Canal - before the locks Agigea and Navodari, and Black Sea along the coast to the Bulgarian border. The average tritium concentration in sea water collected from the sampling locations had the value of 11.1 {+-} 2.1 TU, close to tritium concentration in precipitation. Although an operating nuclear power plant exists in the monitored area, the values of tritium concentration in two locations are slightly higher than those recorded elsewhere. To conclude, it could be emphasized that until now, Cernavoda NPP did not had any influence on the tritium concentration of the Black Sea Shore. (authors)
Varlam, C.; Stefanescu, I.; Popescu, I.; Faurescu, I. [National Inst. for Cryogenic and Isotopic Technologies, PO Box 10, Rm. Valcea, 24050 (Romania)
22 Years of Sea Surface Temperatures
NSDL National Science Digital Library
This NOAA visualization video on YouTube shows the seasonal variations in sea surface temperatures and ice cover for the 22 years prior to 2007 based on data collected by NOAA polar-orbiting satellites (POES). El Niño and La Niña are easily identified, as are the trends in decreasing polar sea ice.
NOAA (National Oceanic and Atmospheric Administration) Visualizations
Direct solar energy conversion at sea
Hydrogen production and delivery from direct solar energy conversion facilities located at sea is treated, assuming the use of a heat engine\\/electricity generation\\/water electrolysis system. The concept of ocean energy is discussed, noting the distinction between direct and indirect solar energy conversion at sea, and direct solar energy conversion is considered within the framework of the seaward advancement of industrial
W. J. D. Escher; T. Ohta
Sea Level: On the Rise Lesson Plan
NSDL National Science Digital Library
"Sea Level: On the Rise" is designed to teach middle-school students about the relationship between climate change and sea-level rise. It is a lesson plan created for the Environmental Protection Agency's Student's Guide to Global Climate Change.
Agency, Environmental P.
Twentieth-century sea surface temperature trends
An analysis of historical sea surface temperatures provides evidence for global warming since 1900, in line with land-based analyses of global temperature trends, and also shows that over the same period, the eastern equatorial Pacific cooled and the zonal sea surface temperature gradient strengthened. Recent theoretical studies have predicted such a pattern as a response of the coupled ocean-atmosphere system
M. A. Cane; A. C. Clement; A. Kaplan
Sea surface temperature measurements with AIRS
NASA Technical Reports Server (NTRS)
The comparison of global sea surface skin temperature derived from cloud-free AIRS super window channel at 2616 cm-1 (sst2616) with the Real-Time Global Sea Surface Temperature for September 2002 shows surprisingly small standard deviation of 0.44K.
Aumann, H.
Ocean Currents and Sea Surface Temperature
NSDL National Science Digital Library
In this classroom activity, students access sea surface temperature and wind speed data from a NASA site, plot and compare data, draw conclusions about surface current and sea surface temperature, and link their gained understanding to concerns about global climate change.
Carter, Joan; Collection, Nasa -.
Inverse electromagnetic scattering models for sea ice
Inverse scattering algorithms for reconstructing the physical properties of sea ice from scattered electromagnetic field data are presented. The development of these algorithms has advanced the theory of remote sensing, particularly in the microwave region, and has the potential to form the basis for a new generation of techniques for recovering sea ice properties, such as ice thickness, a parameter
K. M. Goldenl; D. Borup; M. Cheney; E. Cherkaeva; M. S. Dawson; Kung-Hau Ding; A. K. Fung; D. Isaacson; S. A. Johnson; Arthur K. Jordan; Jin Au Kong; Ronald Kwok; Son V. Nghiem; Robert G. Onstott; J. Sylvester; D. P. Winebrenner; I. H. H. Zabel
Forward electromagnetic scattering models for sea ice
Recent advances in forward modeling of the electromagnetic scattering properties of sea ice are presented. In particular, the principal results include the following: (1) approximate calculations of electromagnetic scattering from multilayer random media with rough interfaces, based on the distorted Born approximation and radiative transfer (RT) theory; (2) comprehensive theory of the effective complex permittivity of sea ice based on
K. M. Golden; M. Cheney; Kung-Hau Ding; A. K. Fung; Thomas C. Grenfell; D. Isaacson; Jin Au Kong; S. V. Nghiem; J. Sylvester; P. Winebrenner
Sea Scallop Shell Lab Teacher's Guide
NSDL National Science Digital Library
Used in combination with the Sea Scallop Lab handout, students will examine sea scallop shells to determine their size, approximate age, and meat yield. This lab activity is complete with objectives, math and science standards, materials list, procedure, and extensions. The handout is available from the COSEE-NE OSEI resource site.
The South Pole and the Ross Sea
NASA Technical Reports Server (NTRS)
This image shows a rare clear view of the South Pole (lower right) and the Ross Sea, Antarctica. The Sea-viewing Wide Field-of-view Sensor (SeaWiFS) acquired the scene on December 26, 2001. The geographic South Pole is located in the center of Antarctica, at an altitude of 2,900 meters (9,300 feet). It rests on a continent-wide ice sheet that is 2,870 m thick, with the underlying bedrock only 30 m (98 feet) above sea level. The ice underlying the South Pole is as much as 140,000 years old, and is currently accumulating at about 82 cm (32 inches) per year. Roughly 2,500 km (1,550 miles) away is the green water of the Ross Sea, which indicates the presence of large numbers of phytoplankton. This is a highly productive part of the world's oceans. Also note the ice gathered around McMurdo Sound, seen toward the lefthand shoreline of the Ross Sea, at the edge of the Ross Ice Shelf. According to National Science Foundation researchers, this ice is making it difficult for penguins to reach their food supply. Separating the continental Antarctic ice sheet from the Ross Sea are the Queen Maud Mountains and the Ross Ice Shelf. Image courtesy the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE
Antarctic Sea Ice covers an area of 20 million km2 at maximum extent and therefore represents an areal coverage larger than either the Arctic ice cover or the Antarctic continent. Studies of Antarctic sea ice in the modern era were only initiated well after the IGY, with the advent of passive microwave satellite coverage in 1973, followed by the use
S. F. Ackley; D. K. Perovich; C. A. Geiger
Light at deep sea hydrothermal vents
We usually think of the bottom of the sea as a dark environment, lit only by flashes of bioluminescent light. Discovery of light associated with geothermal processes at deep sea hydrothermal vents forces us to qualify our textbook descriptions of the seafloor as a uniformly dark environment. While a very dim glow emitted from high temperature (350°) vents (black smokers)
Cindy Lee Van Dover; J. R. Cann; Colleen Cavanaugh; Steven Chamberlain; John R. Delaney; David Janecky; Johannes Imhoff; J. Anthony Tyson
Aquarius: Sea Surface Salinity from Space
NSDL National Science Digital Library
Online in 2009, the Aquarius instrument will measure sea surface salinity. Site provides background information about salinity, salinity lesson plans, and salinity data and tools. Activities include relating salt to density, conductivity, buoyancy, and understanding the effect of the water cycle on salinity. View figures of sea surface salinity and temperature as they change from month to month and more.
Chilean Sea Bass: Off the Menu
NSDL National Science Digital Library
In this data analysis activity, learners use data collected by the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) to study Chilean sea bass populations. Learners formulate catch and catch per unit effort (CPUE) of Dissostichus eleginoides and analyze the trends in these values. Learners also assess the Chilean sea bass population and determine if the population is being overfished.
Lawrence, Lisa A.
Overview of Radioactive Waste Disposal at Sea
For hundreds of years, the seas have been used as a place to dispose of wastes from human activities. Although no high level radioactive waste has been disposed of into the sea, variable amounts of packaged low level radioactive wastes have been dumped at 47 sites in the northern part of the Atlantic and Pacific Oceans. in 1946 the first
Dominique Calmet
Energy exchange processes in the marginal ice zone of the Barents Sea, Arctic Ocean, during spring 1999
NASA Astrophysics Data System (ADS)
We present some new results describing energy exchange processes of drifting sea ice in the marginal ice zone (MIZ) in the Barents Sea, Arctic Ocean. All measurements and observations of meteorological parameters and ice conditions were taken on board the Norwegian research vessel Lance from 3 to 22 May 1999. Components of surface heat balance were measured and correlated with ice conditions and synoptic observations.These results can be used in atmospheric boundary layer modelling as lower boundary conditions. A relationship was found between modelled turbulent heat fluxes and observed sea-ice concentrations.
Ivanov, Boris V.; Gerland, Sebastian; Winther, Jan-Gunnar; Goodwin, Harvey
Sea Grant--A Report on the Oregon State University Sea Grant Program for 1973-1974.
National Technical Information Service (NTIS)
The annual report summarizes various projects undertaken by the Oregon State University Sea Grant Program during the period 1973-1974. Areas under consideration include: Food from the sea (with specific studies in salmon marketing and sea urchin gonads); ...
R. Lovell
75 FR 38935 - Fisheries of the Northeastern United States; Black Sea Bass Fishery; 2010 Black Sea Bass...
Federal Register 2010, 2011, 2012, 2013
...Fisheries of the Northeastern United States; Black Sea Bass Fishery; 2010 Black Sea Bass Specifications; Emergency Rule Extension...extending the emergency action to increase the 2010 black sea bass specifications (i.e., commercial...
75 FR 59154 - Fisheries of the Northeastern United States; Black Sea Bass Fishery; 2010 Black Sea Bass...
Federal Register 2010, 2011, 2012, 2013
...0648-XT99 Fisheries of the Northeastern United States; Black Sea Bass Fishery; 2010 Black Sea Bass Specifications; Emergency Rule Extension...extend the emergency action to increase the 2010 black sea bass specifications. The preamble text of...
75 FR 6586 - Fisheries of the Northeastern United; Black Sea Bass Fishery; 2010 Black Sea Bass Specifications...
Federal Register 2010, 2011, 2012, 2013
...100120036-0038-01] Fisheries of the Northeastern United; Black Sea Bass Fishery; 2010 Black Sea Bass Specifications; Emergency Rule AGENCY: National...rule NMFS is implementing increases to the 2010 black sea bass specifications (i.e., commercial...
Caspian Sea surface circulation variability inferred from satellite altimeter and sea surface temperature
NASA Astrophysics Data System (ADS)
(1993-2007) satellite-derived Sea Level Anomaly (SLA), Sea Surface Temperature (SST), and model-derived mean dynamic topography were used together to analyze climatological and interannual variations of the Caspian Sea surface circulation. Constructed geostrophic currents are in good agreement with the known circulation features of the Caspian Sea, obtained from models and verified by some drifter observations. It is shown that the climatological surface circulation of the Middle Caspian Sea (MCS) is dominated by a basin-wide cyclonic circulation in winter, switching to an anticyclonic circulation in summer. A dipole pattern (an anticyclonic eddy near 39.5°N and a cyclonic one near 38°N) exist in the Southern Caspian Sea (SCS) (stronger from September to January). Evaluation of the multiyear geostrophic velocities shows that the Caspian Sea surface circulation exhibits strong interannual variations, with the location and intensity of the circulation patterns changing from one year to another.
Gunduz, Murat
Quantifying the influence of sea ice on ocean microseism using observations from the Bering Sea, Alaska
Microseism is potentially affected by all processes that alter ocean wave heights. Because strong sea ice prevents large ocean waves from forming, sea ice can therefore significantly affect microseism amplitudes. Here we show that this link between sea ice and microseism is not only a robust one but can be quantified. In particular, we show that 75–90% of the variability in microseism power in the Bering Sea can be predicted using a fairly crude model of microseism damping by sea ice. The success of this simple parameterization suggests that an even stronger link can be established between the mechanical strength of sea ice and microseism power, and that microseism can eventually be used to monitor the strength of sea ice, a quantity that is not as easily observed through other means.
Tsai, Victor C.; McNamara, Daniel E.
Potential for rapid transport of contaminants from the Kara Sea.
Export of sea ice from the Kara Sea may redistribute contaminants entrained from atmospheric, marine and riverine sources. Ice exiting the Kara Sea ice to the north, will influence the Fram Strait, Svalbard and Barents Sea regions. Kara Sea ice may also be exported to the Barents Sea through straits north and south of Novaya Zemlya. Some ice from the Kara Sea makes its way into the Laptev Sea to the north and south of Severnaya Zemlya. Data on ice exchange and contaminant levels are not adequate to assess contaminant flux. PMID:9241881
Pfirman, S L; Kögeler, J W; Rigor, I
Liquid hydrocarbons probable under Ross Sea
Thick glacial strata, which have no source-rock potential, cover the Ross Sea. If these strata persist to great depths, then hydrocarbon-generation prospects will be poor. Deeply buried strata within Ross Sea rift-grabens, if like other Gondwana rift-deposits, could have good potential for hydrocarbon generation. Current hydrocarbon assessments of the Ross Sea and adjacent areas must be considered highly speculative because the deeply buried rift(?) strata have not been sampled in situ. The assessment of the Ross Sea relies on geophysical/geologic data, two-stage rift models, and data from formerly nearby Gondwana rift-basins. We conclude that conditions favorable for hydrocarbon generation and entrapment are likely throughout the Ross Sea, and especially in the Victoria Land basin, if adequate source beds exist. -Authors
Cooper, A. K.; Davey, F. J.; Hinz, K.
Parametric approaches for uncertainty propagation in SEA
NASA Astrophysics Data System (ADS)
A limit of statistical energy analysis (SEA) is that of providing only the mean values of the mechanical energy of a vibrating system. In this paper, the variability of SEA solution under uncertain SEA parameters (coupling loss factors, internal loss factors and injected powers) is investigated by comparing a sensitivity approach and a design of experiment (DoE) approach. Uncertainties of the SEA parameters depend on uncertainties in the physical properties of the considered mechanical system. Numerical results are derived using a benchmark structure made by three aluminum plates with a common junction and a launcher fairing. The analysis of the effect of uncertainties of SEA parameters can be used for design purposes, i.e. to identify which are the most effective areas to modify in order to control the energy level of a given subsystem.
Culla, Antonio; D'Ambrogio, Walter; Fregolent, Annalisa
Volga River Delta and Caspian Sea
NASA Technical Reports Server (NTRS)
This true-color MODIS image from May 10, 2002, captures Russia's Volga River (running south through the center) emptying into the northern portion of the Caspian Sea. The waters of the Caspian Sea are quite murky in this image, highlighting the water quality problems plaguing the sea. The sea is inundated with sewage and industrial and agricultural waste, which is having measurable impact on human health and wildlife. According reports from the Department of Energy, in less than a decade the sturgeon catch dropped from 30,000 tons to just over 2,000 tons. National and international groups are currently joining together to find strategies of dealing with the environmental problems of the Caspian Sea. Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC
In calm seas, precipitation drives air-sea gas exchange
NASA Astrophysics Data System (ADS)
In a series of experiments run in what resembles a heavily instrumented fish tank, Harrison et al. investigated the interwoven roles of wind and rain on air-sea gas exchange rates. Working with a 42-meterlong, 1-meter-wide, and 1.25-meter-tall experimental pool, the authors were able to control the wind speed, rainfall rate, water circulation speed, and other parameters, which they used to assess the effect of 24 different wind speed-rainfall rate combinations on the gas exchange rate of sulfur hexafuoride, a greenhouse gas. In trials that lasted up to 3 hours, the authors collected water samples from the tank at regular intervals, tracking the concentration of the dissolved gas.
Schultz, Colin
Is sea salt in ice cores a proxy of past sea ice extent?
NASA Astrophysics Data System (ADS)
A number of marine, coastal and ice core proxies have been used to try to assess the past extent of sea ice. Sea salt has been proposed as a proxy for past ice extent, at least in the Southern Ocean. The idea is that the sea ice surface itself holds a source of sea salt, that is stronger than the source from the open ocean it replaces. That a sea ice source exists is apparent from observations of the ratio of sulphate to sodium in coastal aerosol and snow samples. While the idea behind using sea salt as a proxy is attractive, and leads to sensible inferences, many doubts remain. Firstly the exact nature of the source remains uncertain, and secondly it is not clear if ice extent, as opposed to changes in atmospheric transport and lifetime, would dominate variability in the ice core record of sea salt. Here we use a model of atmospheric transport and chemistry (p-TOMCAT) to assess the consequences of a sea ice source, focussing particularly on a source that has been proposed to arise from the sublimation of salty blowing snow. We will briefly report some new observations from a winter cruise, that will allow us to comment on the likelihood that blowing snow does pose a significant source. We will then present results from the model (implemented using existing parameters). The model has been run with seasonally and interannually varying sea ice extent and meteorology for the Antarctic, tracking, at different ice core sites, the concentration that arises from the open ocean and sea ice sources. We have already shown that the model, after tuning, is able to reproduce the magnitude and seasonal cycle of sea salt at a range of sites globally. By varying each component separately we explore which factors (sea ice presence, wind speed at source, transporting winds) and which source regions control the delivery of sea salt to sites in Antarctica. Such work suggests that sea salt cannot be used as a sea ice proxy on interannual timescales, but may be suitable on longer timescales. By employing much larger sea ice extents, such as at the last glacial maximum (LGM), we find a strong increase in concentration at ice core sites when ice extent increases. The increase in modelled sea salt concentration tails off sharply as ice approaches the LGM extent, so that the sensitivity of the proxy is greater at lower ice extents, for example in interglacials. We will discuss the implications of this work for the proposed use of sea salt as a sea ice proxy.
Levine, James; Wolff, Eric; Frey, Markus; Jenkins, Hazel; Jones, Anna; Yang, Xin
SEAS Classroom to Sea Labs: New Directions for Ridge 2000 Communitywide Education Outreach
NASA Astrophysics Data System (ADS)
Lessons learned from the two year SEAS pilot program emphasize that student participation in deep-sea research is an important motivator in student learning. Further, SEAS students experience a paradigm shift in understanding evidence-based reasoning and the process of scientific discovery. At the same time, we have learned that fostering authentic student investigations within the confines of the academic year is challenging and only fits classrooms with some academic flexibility. As a result, this year, SEAS will focus on the new Classroom to Sea Lab as a means to help foster student inquiry in the secondary school science classroom. The Classroom to Sea Lab invites student participation in deep-sea research but does so without requiring students to identify and propose suitable sea-going experiments. Classroom to Sea labs are designed to feature current deep-sea research, and emphasize critical skills in laboratory techniques, data collection and analysis, and scientific reporting. Labs are conducted in the classroom (by students) and at sea (by scientists for the students), resulting in parallel datasets for comparison. Labs also feature the work of practicing scientists. An annual Classroom to Sea Report Fair invites students to summarize their findings and submit written analyses for scientist feedback and prizes, emphasizing the importance of communications skills in science. This year, the SEAS program will feature the Shallow-water vs. Deep-sea Vent Mussel Classroom to Sea lab. In this lab, students explore differences in mussel anatomy and feeding strategies, and understand how chemosynthetic symbionts function in this animal. The lab instructs students to dissect shallow-water mussels and measure the proportion of gill tissue to total body tissue. Students are also instructed to download a dataset of vent mussel measurements and compare average proportions. Finally, students are invited to submit their analyses of the lab to the on-line Report Fair sponsored by the Ridge 2000 research community. A primary goal of SEAS is to excite and engage student learners by involving them in actual research in the extreme environments of the deep-sea. The program depends on the contributions of multiple scientists within the Ridge 2000 community. Scientists field student questions during the Ask-a-Scientist email forum, serve as Report Reviewers, are featured in ``Scientist Spotlights,'' host educators during cruises to conduct at-sea portions of a lab, and help develop new labs. It is community involvement that makes the SEAS program possible and so exciting and motivating for students.
Goehring, L.
Sea level rise and submarine mass failures on open continental margins
NASA Astrophysics Data System (ADS)
Submarine mass failures (which include submarine slides or submarine landslides) occur widely on open continental margins. Understanding their cause is of great importance in view of the danger that they can pose both to coastal populations through tsunamis and to the exploitation of ocean floor resources through mass movement of the sea floor. Present knowledge of the causes of submarine mass failures is briefly reviewed, focussing on the role of sea level rise, a process which has previously only infrequently been cited as a cause. It is argued that sea level rise could easily have been involved in at least some of these events by contributing to increased overpressure in sediments of the continental margin whilst causing seismic activity. The Holocene Storegga Slide off South West Norway may have been partly caused by the early Holocene sea level rise in the area, accentuated by meltwater flux from the discharges of Lake Agassiz-Ojibway in North America. Relative sea level rise increased water loading on the Norwegian continen