Experimental investigation of shelf flow crossing over a strait

Joseph Kuehl, University of Delaware, Mechanical Engineering, Newark, DE, United States and Vitalii Sheremet, University of Rhode Island Narragansett Bay, Physical Oceanography, Narragansett, RI, United States
Abstract:
Motivated by the phenomenon of Scotian Shelf Crossover events, the problem of a shelf flow that is interrupted by a strait is considered. Laboratory experiments in a rotating tank with barotropic and baroclinic flow over flat and sloping shelves confirm that the flow is steered by the bathymetric contours and mainly circumnavigates the gulf. In order to jump across the strait, as suggested by earlier theories, the flow must have unrealistically high Rossby numbers. However, the near bottom friction relaxes the bathimetric constraint and causes the formation of a peculiar jet crossing the strait diagonally. Numerical solutions for realistic values of the frictional parameter reproduce the results of the laboratory experiments and are similar to the patterns observed in the satellite derived sea surface temperature fields.