Ocean Circulation Response to Increasing Antarctic Meltwater

Journal of Geophysical Research: Oceans, 10 July 2026

As the Antarctic ice sheet and surrounding ice shelves lose ice, they release increasing amounts of freshwater into the Southern Ocean, altering circulation there as well as globally, potentially influencing the global climate system. To better understand these effects, researchers modeled how projected Antarctic meltwater affects major ocean currents under several meltwater scenarios for 1990-2100. Across all modeled scenarios, increasing freshwater strengthens the upward movement of deep water in the Southern Ocean while slowing the formation of Antarctic Bottom Water (AABW). AABW helps ventilate the deep ocean, and drives much of global ocean circulation systems. These changes may temporarily increase the strength of the Atlantic Meridional Overturning Circulation (AMOC) throughout the 21st century. However, the study suggests this effect is likely temporary beyond 2100, as meltwater from Greenland begins to have greater impact than that from Antarctica. These findings highlight the risks and complexity of interactions between ice loss already occurring at both poles today, but especially with greater and more rapid future warming.

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