Intensification of Westerly Winds Surrounding Antarctica Increases Ice Loss

Communications Earth & Environment, 22 June 2022

The Southern Annular Mode, or SAM, is a belt of strong air currents that influence precipitation and weather patterns across the Southern Ocean. During their “positive” phase, these winds constrict around Antarctica; this increases the upwelling of warm water from deep circumpolar currents that circle the ice sheet. Rising global temperatures have strengthened the flow of “positive” SAM winds around Antarctica, pushing warm water against the base of ice shelves. These warm waters erode ice shelves at their base, accelerating melting and increasing the vulnerability of that region to collapse; and potentially destabilizing neighboring glaciers. For more than seventy years, increasingly positive SAM winds have exacerbated ice loss from most regions of Antarctica, especially in the Western Pacific and Bellingshausen sectors and the Antarctic Peninsula. Authors underscore the urgency in reducing emissions to curb global temperature rise and minimize further amplification of Antarctic ice loss caused by positive phase SAM winds.

https://www.nature.com/articles/s43247-022-00458-x