FORMATION AND DISCHARGE OF DEEP AND BOTTOM WATER IN THE NORTHWESTERN WEDDELL SEA

Deep and bottom water formation in the Weddell Sea is the major source of the bottom water of the world ocean. Measurements made in the northwestern Weddell Sea between 1989 and 1993 during the 'Weddell Gyre Study' indicate that the outflow of young bottom water with the western boundary current of the Weddell Gyre is dominated by a rather fresh water mass which obtains its thermohaline characteristics by mixing of deep water with a flow from the shelf in front of the Larsen Ice Shelf. The more saline source water mass, which is necessary to maintain the thermohaline properties of the Weddell Sea Deep Water, is less prominent in the bottom water outflow. The transport of bottom water with the western boundary current of the Weddell Gyre ranges from 1 to 4 10(6) m(3)s(-1). The outflow is subject to a seasonal cycle with minimum temperatures and maximum velocities in early austral winter.