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A physical mechanism of the atmospheric response over Antarctica to decadal trends in tropical SST
Author(s) -
Grassi Barbara,
Redaelli Gianluca,
Visconti Guido
Publication year - 2006
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 - 10.1029/2006gl026509
Subject(s) - climatology , sea surface temperature , atmospheric sciences , environmental science , atmospheric circulation , latitude , convection , perturbation (astronomy) , walker circulation , tropical cyclone , atmospheric dynamics , forcing (mathematics) , geology , meteorology , physics , geodesy , quantum mechanics
The atmospheric response to the tendency of oceanic equatorial temperature observed during recent decades has been simulated, leading to the identification of a possible link between tropical Sea Surface Temperature (SST) and Antarctic climate change. The dynamical mechanism, by which changes in tropical SSTs exert an influence on the upper latitude atmospheric dynamics, is investigated. The analysis of the simulations suggests that the perturbations of the atmospheric circulation are induced by changes in the annual cycle of the tropical convective activity, which influences the intensity of the wave forcing. In particular, the introduction of the SST perturbation generates a strong vertical wind shear at middle latitude during the Antarctic winter affecting the propagation of convectively generated waves during the following spring.