The adjustment of barotropic currents at the shelf break to a sharp bend in the shelf topography
Williams, William J.
MetadataShow full item record
During January-March, Scotian Shelf water has been observed to flow episodically from the southwestern Scotian Shelf directly across the Northeast Channel to Georges Bank. The possible factors that allow Scotian Shelf water to break the topographic constraint presented by the Northeast Channel and flow directly to Georges Bank are considered. As a simple analog to the flow over the southwestern Scotian Shelf near the Northeast Channel, the adjustment of a barotropic current near a shelf-break to a sharp bend in the shelf topography is studied numerically. For parameters within the oceanographic range, the adjustment to the bend is smooth and steady with no eddies shed at the corner. The vorticity dynamics allow a balance between the vortex stretching in the flow and the curvature in the flow. This is possible since the bend is a right-hand one facing downstream, a similar balance not being possible for a left-hand bend, in which case eddy formation is likely. A simple model of this balance clarifies the vorticity dynamics and provides the scaling rc = √eL/0.765 for any streamline in the flow, where rc is the radius of curvature at the corner, E = u0/fL and L = h0/b, where uo is the initial speed, f the coriolis parameter, h0 the initial depth and b the bottom slope. These results show that other factors such as stratification, wind stress, and time-dependent inflow must play a role in any flow across the Northeast Channel.
Submitted in partial fulfillment of the requirements for the degree of Master of Science at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution February 1996
Suggested CitationThesis: Williams, William J., "The adjustment of barotropic currents at the shelf break to a sharp bend in the shelf topography", 1996-02, DOI:10.1575/1912/5674, https://hdl.handle.net/1912/5674
Showing items related by title, author, creator and subject.
Slope/shelf circulation and cross-slope/shelf transport out of a bay driven by eddies from the open ocean Zhang, Yu (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2009-09)Interaction between the Antarctic Circumpolar Current and the continental slope/shelf in the Marguerite Bay and west Antarctic Peninsula is examined as interaction between a wind-driven channel flow and a zonally uniform ...
Flagg, Charles Noel (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1977-04)A 37 day long field program was carried out in March 1974 on the New England continental shelf break to study the current and hydrographic structure and variability on the shelf and in the shelf/slope front. A second ...
Ice shelf-ocean interactions in a general circulation model : melt-rate modulation due to mean flow and tidal currents Dansereau, Veronique (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2012-09)Interactions between the ocean circulation in sub-ice shelf cavities and the overlying ice shelf have received considerable attention in the context of observed changes in flow speeds of marine ice sheets around Antarctica. ...