CIRCULATION AND TRANSPORT OF WATER ALONG THE WESTERN WEDDELL SEA MARGIN

Ocean current, temperature, and salinity data obtained from the wester n Weddell Sea during the austral winter 1992 U.S.-Russian drifting ice station experiment Ice Station Weddell 1 (ISW-1) are used to describe water circulation and transport. Surface-to-bottom baroclinic current s were computed by applying the geostrophic approximation to derived d ensity data. These were corrected using current measurements obtained from drifting current meter arrays, and the resulting total currents w ere vertically integrated to obtain volume transports. Transport was f ound to be northward in the region, which encompassed the western boun dary current of the cyclonic Weddell Sea gyre. This northward transpor t increased from south to north by more than a factor of 2, from about 12 x 10(6) m(3) s(-)1 in the southwestern Weddell to about 28 x 10(6) m(3) s(-)1 farther north. The increase in northward transport was com pensated for by westward flow from the interior of the gyre into the w estern boundary region. About 5-6 x 10(6) m(3) s(-1) of the northward transport was contained in a 300-500 m thick bottom layer of cold wate r. This layer, whose transport increased by about 1 x 10(6) m(3) s(-1) from south to north, was identifiable by its water mass characteristi cs as Weddell Sea Bottom Water originating on the southwestern and wes tern shelf regions. Its north flowing volume was consistent with past estimates of a 1.5-2 x 10(6) m(3) s(-1) production rate coupled with a 300-400% transport increase due to entrainment during downslope flow from the shelves to the deep basin. The maximum (northernmost) northwa rd transport, less the bottom water transport, is consistent with prev ious estimates for wind-driven transport in the Weddell Gyre provided that bottom friction and the sea ice influence on wind forcing are tak en into consideration.