Seasonal range prediction over North America has been based on intraseasonal variability related to the Pacific North America (PNA) pattern as well as the interannual variability related to El Nino and Southern Oscillation (ENSO). These teleconnective phenomena have an impact on atmospheric blocking which also have an impact on long-term conditions for North America. Similar relationships may be of use for seasonal range prediction over South America as well. Previous studies have examined ENSO-related variability on the South Pacific Jetstream as well as that of atmospheric blocking. Using the National Centers for Environmental Prediction / National Center for Atmospheric Research (NCEP / NCAR) reanalyses, the character of the winter and summer season circulations were studied over the South Pacific / South America sector from 2000 – 2016. Initial results show that there is a negative correlation in the upper air circulation over the East Pacific and South America from winter to summer. Also, the interannual variability in the jet-stream pattern for the region as related to ENSO shows a 180 degrees phase difference. Finally, there is evidence that the circulation pattern for the 2000 – 2016 may be different from that of the latter part of the 20th century as indicated by a recent reversal of the internannual variability of atmospheric blocking over the South Pacific Region.
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ENSO Related Seasonal Range Prediction over South America
Published: 17 July 2017 by MDPI in The 2nd International Electronic Conference on Atmospheric Sciences session Climate and Interannual Variability
Keywords: ENSO, climate variability, blocking, long range forecasting, teleconnections
Utabiri wa msimu wa Amerika ya Kaskazini umejengwa juu ya mabadiliko ya msimu unaohusiana na muundo wa Amerika ya Kaskazini ya Pasifiki (PNA) na mabadiliko ya kati ya miaka yanayohusiana na El Niño na Oscillation ya Kusini (ENSO). Matukio haya ya teleconnective yana athari kwa kuzuia angahewa ambayo pia ina athari kwa hali ya muda mrefu kwa Amerika Kaskazini. Mahusiano kama hayo yanaweza kutumika kwa utabiri wa msimu juu ya Amerika Kusini pia. Uchunguzi wa awali umechunguza mabadiliko yanayohusiana na ENSO kwenye Mtiririko wa Jet wa Pasifiki Kusini na vile vile kuzuia angahewa. Kwa kutumia uchunguzi wa Kituo cha Taifa cha Utafiti wa Anga (NCEP-NCAR), tabia ya mzunguko wa majira ya baridi na majira ya joto ilichunguzwa katika sekta ya Kusini mwa Pasifiki ya Amerika Kusini kutoka 2000 hadi 2016. Matokeo ya awali yanaonyesha kwamba kuna uhusiano hasi katika mzunguko wa hewa juu ya Pasifiki Mashariki na Amerika Kusini kutoka majira ya baridi hadi majira ya joto. Kwa kuongezea, mabadiliko ya kati ya mwaka katika muundo wa mkondo wa jet kwa mkoa huo kama inahusiana na ENSO inaonyesha tofauti ya awamu ya digrii 180. Mwishowe, kuna ushahidi kwamba muundo wa mzunguko wa 2000-2016 unaweza kuwa tofauti na ile ya sehemu ya mwisho ya karne ya 20, kama inavyoonyeshwa na kubadilika kwa hivi karibuni kwa mabadiliko ya ndani ya mwaka ya kuzuia angahewa juu ya eneo la Pasifiki Kusini. "Mwaka wa 2017: ""Mwaka wa 2017"" ni kipindi cha utafiti wa hali ya hewa na hali ya hewa katika nchi za Ulaya na Ulaya, na kinachohusiana na hali ya hewa na hali ya hewa katika nchi za Ulaya na Ulaya, na kinachohusiana na hali ya hewa na hali ya hewa katika nchi za Ulaya na Ulaya."