On the processes controlling shelf–basin exchange and outer shelf dynamics in the Bering Sea

Abstract

Abstract We use a 9-km pan-Arctic ice–ocean model to better understand the circulation and exchanges in the Bering Sea, particularly near the shelf break. This region has, historically, been undersampled for physical, chemical, and biological properties. Very little is known about how water from the deep basin reaches the large, shallow Bering Sea shelf. To address this, we examine here the relationship between the Bering Slope Current and exchange across the shelf break and resulting mass and property fluxes onto the shelf. This understanding is critical to gain insight into the effects that the Bering Sea has on the Arctic Ocean, especially in regard to recent indications of a warming climate in this region. The Bering Sea shelf break region is characterized by the northwestward-flowing Bering Slope Current. Previously, it was thought that once this current neared the Siberian coast, a portion of it made a sharp turn northward and encircled the Gulf of Anadyr in an anticyclonic fashion. Our model results indicate a significantly different circulation scheme whereby water from the deep basin is periodically moved northward onto the shelf by mesoscale processes along the shelf break. Canyons along the shelf break appear to be more prone to eddy activity and, therefore, are associated with higher rates of on-shelf transport. The horizontal resolution configured in this model now allows for the representation of eddies with diameters greater than 36 km; however, we are unable to resolve the smaller eddies.