Antarctic Peninsula warm winters influenced by Tasman Sea temperatures

The Antarctic Peninsula of West Antarctica was one of the most rapidly warming regions on the Earth during the second half of the 20th century. Changes in the atmospheric circulation associated with remote tropical climate variabilities have been considered as leading drivers of the change in surface conditions in the region. However, the impacts of climate variabilities over the mid-latitudes of the Southern Hemisphere on this Antarctic warming have yet to be quantified. Here, through observation analysis and model experiments, we reveal that increases in winter sea surface temperature (SST) in the Tasman Sea modify Southern Ocean storm tracks. This, in turn, induces warming over the Antarctic Peninsula via planetary waves triggered in the Tasman Sea. We show that atmospheric response to SST warming over the Tasman Sea, even in the absence of anomalous tropical SST forcing, deepens the Amundsen Sea Low, leading to warm advection over the Antarctic Peninsula. The Antarctic Peninsula sees some of the strongest warming of the whole continent over the last decades, the drivers of which are not well known. Here, the authors show that winter sea surface temperature increases in the Tasman sea lead to changes in Southern Ocean storm tracks that in turn warm the Antarctic Peninsula.

Automated summary

This study reveals that increases in winter sea surface temperature in the Tasman Sea modify Southern Ocean storm tracks, leading to warming over the Antarctic Peninsula.