Transient response of the Meridional Overturning Circulation to Antarctic freshwater release: coupled and ocean-only results Abstract

Montag 16.06.2025, 11:00 → 12:00 Europe/Berlin

5-1.214 - Linke Seite – Großer, unterteilbarer Konferenzraum (GEOMAR - Standort Ostufer / GEOMAR - East Shore)

Speaker: Dr. Riccardo Farneti, International Centre for Theoretical Physics, Trieste, Italy

Hybrid  -  online via https://geomar.webex.com/geomar-en/j.php?MTID=mf415834ed76a742bacf01eada863885d

Meeting number: 2787 635 2083
Password: XYwu583sQtA

Abstract
Mass loss from the Antarctic ice sheet (AIS) is projected to continue and accelerate over the coming century. Current state-of-the-art climate models typically do not couple ice sheets to the atmosphere-ocean system, and the impact of ice sheet melt has often been studied by injecting meltwater at the model ocean surface. This freshwater input from AIS melting is expected to impact significantly Southern Ocean dynamics and climate, as well as the global climate system. Here, the focus will be on the Global Meridional Overturning Circulation response, and in particular on Atlantic Meridional Overturning Circulation (AMOC) changes and stability. Data from the Southern Ocean Freshwater Input from Antarctica (SOFIA) initiative, and a series of sensitivity experiments performed with an ocean-sea ice model, are used to assess the transient response of the AMOC both qualitatively and quantitatively. Although many efforts have been devoted to studying the AMOC stability to freshwater release in the North Atlantic due to Greenland ice sheet melting, we will show that plausible values of future AIS mass loss can lead to significant weakening of the AMOC within a century, preceded by an initial strengthening.