A model study of ocean circulation beneath Filchner-Ronne Ice Shelf, Antarctica: Implications for bottom water formation

An isopycnic coordinate ocean circulation model has been applied to the southern Weddell Sea, including the cavity beneath Filchner-Ronne Ice Shelf, with the aim of investigating the buoyancy-forced circulation on the continental shelf. Buoyancy forcing is associated with both the annual growth and decay of sea ice and the interaction between ice shelf and ocean. In the model a generally anti-cyclonic circulation develops beneath the ice shelf, so that new shelf waters entering the cavity in the west emerge colder and fresher in the east. The outflow contributes to a dense current that spills off the continental shelf and descends the slope. Oceanographic observations from the region are consistent with this picture and highlight the overflow as a major source of Weddell Sea Bottom Water.