Observations of the Aleutian North Slope Current, Bering Sea, 1996-2001

Abstract

Cyclonic circulation dominates flow in the Bering Sea basin. The eastward flowing Aleutian North Slope Current (ANSC) flows along the north slope of the Aleutian Islands, turning northwestward in the southeast corner of the basin to form the Bering Slope Current (BSC). During the period 1997 to 2007, a pair of hydrographic lines was occupied 14 times in the southeastern portion of the basin. One transect was across the ANSC, and the second was across the BSC. In addition, a series of five yearlong moorings was deployed in a water depth of 1000 m in the ANSC, and a single yearlong mooring was deployed to the northeast in a water depth of 2200 m. At the primary mooring site, strong variability in temperature and salinity occurred at fortnightly and annual periods, while strong variability in the currents occurred at fortnightly and semiannual periods. The mean geostrophic flow relative to 1500 m, calculated from the 14 occupations of the hydrographic lines, was 3.1 × 106 m 3 s-1 in the ANSC and 3.3 × 106 m 3 s-1 in the BSC. A significant barotropic component, measured by the current meters, adds ∼3 × 106 m3 s-1 to the transport.