Weddell Gyre Physical Oceanographic Studies

The proposed work is the lead project in an integrated research program into the oceanographic structure of the western Weddell Sea. It is to be carried out from an ice camp jointly occupied by U.S. and USSR scientists from February to June 1992. This project concerns the large-scale oceanographic circulation and the variability of the Weddell Sea boundary current, and how these affect and are affected by the regional water mass formation and modification processes. The Weddell Sea may be divided into three regions on the basis of the energy exchange mode. The warm regime occurs in the east where the intrusion of warm circumpolar deep water keeps the water temperature nea +1 deg C. The cold regime occurs in the center, where deep water is overlain by a thick near freezing mixed layer. In both regions however enough heat is seasonally carried to the sea ice to melt it completely. In the western region, the sea ice cover does not melt, and it is expected that the thermodynamics processes will be different. Hydrographic data, coupled with the current meter observations, chemical tracer experiments, turbulent flux measurements, and sea ice dynamics that are part of this project, will provide a unique picture of the Weddell Sea continental slope processes.