Bering Strait is a narrow and shallow water passage that connects the Bering Sea to the Chukchi Sea. As the only Pacific connection to the Arctic Ocean, the flow through Bering Strait is responsible for contributing to several water masses including the halocline of the Arctic Ocean, which separates the Arctic Surface Water from the warmer and saltier Atlantic Layer found deeper in the water column. Historical observations of the flow through Bering Strait estimate a mean volume transport of ~0.8 Sv northward that is primarily driven by the large-scale gradient in sea surface height. In recent years, near-bottom mooring observations have indicated an increasing trend in the volume, heat, and freshwater fluxes from the Pacific Ocean to the Arctic Ocean through the Bering Strait.

We have designed a series of model experiments to test the sensitivity of the Pacific Arctic oceanic heat convergence, heat exchange with the atmosphere, and impact on sea ice cover to the flow through Bering Strait. Utilizing the fully-coupled Regional Arctic System Model (RASM) we will compare 4 runs that have increasingly higher mean volume transport through Bering Strait. These include the control run (which approximates the historical mean volume transport), as well as runs with doubled, tripled, and quadrupled mean volume transport. All of these runs cover the time period from 1980-2018. Results on the heat terms within the ocean and into/out of the atmosphere from these experiments help quantify the heat budget of the Pacific Arctic, which includes the Chukchi, Beaufort, and East Siberian seas. This work will address questions related to the Bering Strait’s importance and connection with melting of sea ice in the Pacific Arctic, which is an area that has experienced a dramatic loss of sea ice cover in the past two decades. We find that doubling the volume transport through Bering Strait produces a threefold increase in the oceanic heat convergence into the Pacific Arctic. However, instead of causing a large impact on the melting of sea ice, much of this heat is released to the atmosphere as it transits the shallow Chukchi Sea shelf. This indicates that although the flow through Bering Strait has a modest local impact on sea ice, other large-scale factors appear to play a greater role on the loss of sea ice in the Pacific Arctic.