Deep Ocean Heat Triggers Antarctica's Sudden Sea-Ice Decline

Antarctic sea ice began a rapid, decade-long decline around 2016 after a “violent release” of heat from the deep ocean. Argo floats tracked warming temperatures and salinity shifts, showing that deeper warmth, churned up by winds and a fresher surface layer, prevented ice formation and hindered recovery. The findings underscore the ocean’s key role in decadal sea-ice variability and have implications for adjacent ice shelves and potential sea-level rise, though the long-term trend remains negative as the climate continues to warm.