Mesoscale oceanographic features associated with the central Bering Sea ice edge: February–March 1981

Abstract

Midwinter 1981 observations from the central Bering Sea shelf showed a hydrographic structure which was two layered in temperature, salinity, and density. This structure was confined to a 100‐km‐wide band which coincided approximately with the ice edge. The colder, lower‐salinity upper layer was continuous in its T‐S properties with homogeneous water to the north beneath the ice. The warmer, more saline lower layer was similarly continuous with water to the south near the shelf break. A northwestward baroclinic flow of the surface relative to 75 dbar was associated with the layered structure. The layered structure and associated flow appear to be regular winter features associated with the ice edge in this region. Input of low‐salinity water from melting of ice along the edge is adequate to maintain the layered structure, and its associated baroclinic circulation, against the effects of tidal and wind mixing. The resulting observed oceanographic features were similar to those which have been found in association with midshelf and shelf break fronts in other regions and appear to define a dynamically controlled boundary between the cold, low‐salinity water on the northern shelf and the warmer, more saline water near the shelf break.