Impacts of Eastern Arctic Eurasian Basin Water Mass Properties on the AMOC and Beaufort Sea Atlantic Water Layer

Abstract In this study, we investigate the impacts of the eastern Arctic water mass properties on the Atlantic Meridional Overturning Circulation (AMOC) and the Beaufort Sea thermal structure by constraining the eastern Arctic in a coupled model using the observed hydrographic climatology. Our results demonstrate that a colder saltier eastern Arctic (Eurasian Basin) could densify the Arctic outflow, shifting the AMOC across Arctic‐Atlantic gateway sections and across eastern subpolar North Atlantic toward denser levels. The results support the view that the Arctic is the northern terminus of the AMOC, and the Arctic outflow provides the densest water to the AMOC. Meanwhile, the colder/thinner Atlantic Water (AW) layer in the eastern Eurasian Basin propagates westward to the Canadian Basin and leads to a more realistic AW layer in the Beaufort Sea (BS), revealing eastern Eurasian Basin as a key region causing modeled AW layer biases in the BS.