Antarctic Sea Ice Loss Rapidly Reverses Trends in Ocean's Freshwater Engine

New research published in Nature Climate Change reveals that the Antarctic Intermediate Water (AAIW), a vast layer of freshwater in the Southern Hemisphere's ocean, has undergone a rapid reversal in its long-term salinity and density trends. From 2016 to 2024, reduced freshwater input from Antarctic summer ice melt caused the AAIW to become saltier, denser, and deeper, a significant shift from the 1995-2015 period. This change, observed directly, suggests a potential underestimation of deep-ocean warming and rising sea levels.