FY 1985

On the Bering Sea ice edge front

Muench, R.D., and J.D. Schumacher

J. Geophys. Res., 90(C2), 3185–3197, doi: 10.1029/JC090iC02p03185 (1985)

An oceanographic field program was carried out along the Bering Sea ice edge in winter 1982–83 to investigate the temperature/salinity front associated with and paralleling the winter ice edge. Currents were measured using taut-wire moorings that were in place over winter, and an intensive CTD survey was carried out of the frontal structure in midwinter (February–March). The midwinter front separated cold (<–1.5°C), low salinity (<32‰), middle Bering shelf water from warmer (>0°C), more saline (>32.5‰) outer-shelf water. The front had northwestward baroclinic currents paralleling the front/ice edge with near-surface speeds of 5-6 cm/s and an associated transport of about These baroclinic currents were superimposed on a regional barotropic along-isobath flow, resulting in northwestward midwinter upper-layer flows with monthly mean speeds exceeding 10 cm/s. An upper-layer flow component was directed beneath the ice and provided heat adequate to melt the ice and limit advance of the edge. The resulting low-salinity meltwater was mixed vertically, to maintain the front, by wind acting across a highly mobile, hydrodynamically rough ice cover. Subtidal fluctuations were not significantly affected by the front or the ice cover, and local winds accounted for less than one quarter of the observed current variability, the remainder being probably due to regional variations in the barotropic flow.