Hydrographic observations from the Weddell Sea during the Norwegian Antarctic Research Expedition 1976/77

Abstract

CTD observations from the southern Weddell Sea in 1977 show that Ice Shelf Water originating under the floating Filchner Ice Shelf overtlows at the sill of the Filchner Depression and can be identified on the continental slope at more than 2000m depth. Intrusions of Weddell Deep Water upon the shelf are especially noticeable in the region of dense shelf water outflow and are possibly driven by the outflow. Anomalous low core temperature of Weddell Deep Water is probably related to winter convection in the Weddell Polynya. Anomalous CTD stations at the periphery of the 1976 winter polynya region indicate that deep convection phenomena, as reported by Gordon (1978), are perhaps quite common. The observations indicate that double diffusive convection is important for vertical heat transport in the central Weddell Sea.