Arctic gateways, sea level and climate changes in the subpolar North Atlantic

Paleoceanographic records demonstrate linkages between the increasing Pacific water flux accompanying the postglacial submergence of the shallow (~ 50 m deep) Bering Strait and the progressive warming of the Western Arctic until ca. 4000 years BP (cf. de Vernal et al. Sci. Adv. 2024). The Pacific water flux also impacts the freshwater budget of the Arctic Ocean, which ultimately plays a role in the Arctic sea ice and freshwater export rate to the northern North Atlantic. Sea-level changes thus deserve special attention from an Arctic perspective as they can considerably modify the exchanges between the Pacific and Arctic oceans. Furthermore, sea level determines the status of the Arctic shelves, submerged or not, which in turn plays a role in sea-ice production, as well as in the latent heat from the Atlantic water mass flowing northward through Fram Strait and the Barents Sea. We hypothesize that the increased freshwater inflow from the Pacific into the Arctic and the enhanced sea ice formation rates resulting from the sea level rise have played a role in the large scale cooling trend of the eastern Arctic and subarctic North Atlantic that has marked the late Holocene.