Interdecadal changes of tropospheric circulation in Southern extratropics during the recent warming in the Antarctic Peninsula

Summary An analysis of changes of atmospheric circulation in the Southern Hemisphere in relation to recent warming at the Antarctic Peninsula in last thirty years is presented. The sea level pressure and geopotential fields change in 1960-2000 are considered. It was shown that large-scale baric formations of the Southern Hemisphere had displaced to the west about 15-20o during this period. It resulted in the warm winters in last years at the Antarctic Peninsula region. The approach to the classification of meteorological fields based on the method of analogs of synoptic processes (etalon-field method) is briefly described and applied to extra tropical sector of Southern Hemisphere that includes Antarctic. The most informative ‘etalon ’ weather patterns were set off for each decade 1960-2000. Predominant weather pattern in 1990s shows more intensive cyclonicity, with series of cyclones west of the Antarctic Peninsula, and depression at the Bellingshausen Sea in the place of the ridge in 1960s. Citation: Martazinova V., Tymofeyev V. (2007), Recent warming at the Antarctic Peninsula as viewed against changes in atmospheric circulation,in Antarctica: A Keystone in a Changing World – Online Proceedings of the 10th ISAES X, edited by A. K. Cooper and C. R. Raymond et al., USG