Drivers of Antarctica’s Record-Low Sea Ice Decline

Science Advances, 8 May 2026

Antarctic sea ice has remained at historically low levels since 2015, driven by shifts in Southern Ocean winds that pulled heat from the deep ocean to the surface and weakened the separation between ocean layers – adding to growing evidence that Antarctica may have entered a new era of reduced sea ice. The study identified three stages in this decline over the past decade. First, in the early-to-mid 2010s, westerly winds around Antarctica began drawing warm deep water closer to the surface. Second, unusually strong winds in 2015-2016 increased mixing between deep and surface waters, allowing heat to reach the surface and trigger rapid sea ice loss, especially in East Antarctica. Third, after 2018, the sea ice decline itself turned surface waters warmer and saltier, making it more difficult for sea ice to grow in winter. The study also found important regional differences. In East Antarctica, sea ice loss was driven mainly by heat rising from the ocean below, while in West Antarctica it was linked to increased cloud cover and heat trapped near the surface of the ocean. Continued fossil fuel emissions could reinforce these conditions, pushing the Southern Ocean further into low sea ice conditions.

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