FY 1996

ADCP-referenced geostrophic circulation in the Bering Sea basin

Cokelet, E.D., M.L. Schall, and D.M. Dougherty

J. Phys. Oceanogr., 26(7), 1113–1128 (1996)

A month-long circumnavigation of the Bering Sea basin in August 1991 was designed to study the basin-scale circulation. For the first time in this region vessel-mounted acoustic Doppler current profiler (ADCP) measurements provided an absolute reference for geostrophic currents. Transport in the Alaskan Stream (0/1500 db) was 24 Sv (Sv ≡ 10⁶ m³ s⁻¹) westward, considerably higher than the 10-15 Sv usually inferred from geostrophic calculations referred to 1500 db, but in good agreement with previous work relative to moored current meters. As previously reported, the stream separated from the Aleutian Ridge, forming an anticyclonic eddy that restricted inflow to the Bering Sea. Flow through the Aleutians varied substantially across the passes. The Kamchatka Current was traceable for 800 km until it left the Bering Sea carrying 14 Sv (0/3000 db). Eddies were detected from the clustering of centers of curvature of sequential ADCP vectors. Incompletely spanned eddies can bias transports. Counterrotating eddy pairs deflected and entrained Kamchatka Current water and transported it to the basin interior.