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Are tropical SST trends changing the global teleconnection during La Niña?
Author(s) -
Kumar Arun,
Jha Bhaskar,
L'Heureux Michelle
Publication year - 2010
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2010gl043394
Subject(s) - teleconnection , climatology , sea surface temperature , tropics , context (archaeology) , environmental science , northern hemisphere , southern hemisphere , el niño southern oscillation , latitude , pacific decadal oscillation , atmospheric sciences , geology , paleontology , geodesy , fishery , biology
From 1950 to 2008, the linear trend of tropical sea surface temperature (SST) indicates the largest warming across the Indian and western Pacific Oceans, while the eastern Pacific trend is slightly negative. The interannual SST variations due to the El Niño‐ Southern Oscillation (ENSO) are superimposed onto these longer‐term SST trends, which can potentially influence the structure and amplitude of the resulting atmospheric teleconnections. In this study, the cold phase of ENSO, or La Niña, is examined using composite differences based on the observations and the model‐simulated response to SSTs. The analyses show that during the recent period (1980–2008), the global teleconnection pattern associated with La Niña has been associated with higher heights from the tropics to the mid‐latitudes. The model simulations attribute these apparent changes in the teleconnections, across the tropics and the Northern Hemisphere, to warmer SSTs in the Indian Ocean and warm pool region. The implications of these results are discussed within the context of seasonal predictions in an evolving climate.