Bathymetric Recirculations in the Labrador Sea

Float data from the Labrador and Irminger Seas have revealed a number of permanent recirculation cells offshore of the shelf-break boundary current. Previous studies have concluded that these cells form as a result of cyclonic wind forcing east of Greenland, however we argue here that they instead arise from interactions between the boundary current and the continental shelf and slope. Two issues are noteworthy; winds in the area are variable, and are therefore not obvious candidates to drive the relatively small-scale steady recirculations. Second, float data with overlaid bathymetry contours clearly show that recirculations are established where the boundary current crosses isobaths into deeper water. Numerical experiments with idealized and realistic bathymetry confirm that such interactions can result in recirculations, and that wind forcing is of lesser importance.