Prospects of overturning in a future Arctic Ocean

The Atlantic Meridional Overturning Circulation (AMOC) is projected to experience a slowdown due to anthropogenic global warming. Concurrently, the Arctic Ocean is undergoing rapid transformations, including retreating sea ice extent, changing freshwater inputs from rivers and melting ice and increased Atlantic Water (AW) heat transport and air-sea heat fluxes. Following the realization that not only the Nordic Seas, but also the Arctic Ocean is a major component in sustaining the AMOC, the Arctic Ocean has emerged as a region of particular interest for further research. In the Arctic Ocean, the transformation of AW yields two key products, related to distinct overturning circulation branches: dense overflow waters, contributing to the thermal overturning branch, and Polar Waters (PW) created by mixing with freshwater from sources like rivers and melting ice, forming the estuarine circulation branch. Here we will discuss an outlook for the Arctic Ocean overturning in a future climate, as well as some of the processes involved in potentially counterbalancing AMOC decline. For instance, recent research contrastingly highlights the potential for a northward shift of deep convection areas, strengthening Arctic overturning, and the potential for the collapse of one of its overturning cells.