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Abstract

Over the last half of 20th century, climate changes around Antarctica were characterized by a zonally asymmetric, West-Antarctica warming - East-Antarctica cooling pattern. Nevertheless, a series of recent station records revealed that at least part of East Antarctica is experiencing a rapid warming, although the sparse in-situ observations and the disagreement among satellites and reanalysis datasets prevent us from a clear and systematic understanding of these temperature trends. We thus synthesize the temperature signal using the maximized covariance analysis. We retrieve a seesaw SAT pattern between East- and West-Antarctica, whose phase reversed before and after 2000, especially during austral spring. Further investigation based on statistical analysis and numerical simulations reveals that this reversed seesaw pattern is primarily driven by an anomalous circulation center over the Peninsula-Weddell Sea, tightly related to the second Pacific-South America mode.