Patagonian Ice Sheet discharge enhanced by AMOC slowdown through thermal bipolar seesaw

Abstract

Significance The Atlantic Meridional Overturning Circulation (AMOC), a major regulator of global climate, is weakening under ongoing warming, yet its far-field impacts remain uncertain. Past AMOC slowdown events during the last glacial period provide insights into how such changes propagate beyond the North Atlantic. By combining new marine sediment records from the South Pacific off Chile with long-term climate model simulations, we reveal that AMOC slowdowns enhanced precipitation along the Chilean margin by intensifying the Southern Hemisphere Westerly Winds and warming the South Pacific. These changes promoted sediment and meltwater discharge from the Patagonian Ice Sheet and may have strengthened Southern Ocean ventilation. Our findings demonstrate that AMOC weakening can trigger rapid, far-reaching hydroclimatic impacts extending into the Southern Hemisphere midlatitudes.