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November 18-20, 2003 U.S. GLOBEC Georges Bank Sheremet
Multiple Flow Pathways of the Scotian Shelf Water onto Georges Bank
V. Sheremet, Y.-K. Cho,
R. Beardsley
November 18-20, 2003 U.S. GLOBEC Georges Bank Sheremet
Topography and Circulation
November 18-20, 2003 U.S. GLOBEC Georges Bank Sheremet
16 February 1999 crossover
November 18-20, 2003 U.S. GLOBEC Georges Bank Sheremet
5 March 1997 crossover
November 18-20, 2003 U.S. GLOBEC Georges Bank Sheremet
Mooring records
November 18-20, 2003 U.S. GLOBEC Georges Bank Sheremet
Drifters
November 18-20, 2003 U.S. GLOBEC Georges Bank Sheremet
Important Factors
• Freshwater pulses from the Gulf of St. Lawrence
• Along-shelf flow in the shelf/slope front
• Instability of the SSW front around Browns Bank
• Synoptic wind events
• Warm-core rings
November 18-20, 2003 U.S. GLOBEC Georges Bank Sheremet
Williams et al. 2001
November 18-20, 2003 U.S. GLOBEC Georges Bank Sheremet
Numerical modeling
November 18-20, 2003 U.S. GLOBEC Georges Bank Sheremet
Bathymetry
November 18-20, 2003 U.S. GLOBEC Georges Bank Sheremet
Abrupt changes: 1.5 C
November 18-20, 2003 U.S. GLOBEC Georges Bank Sheremet
Kuroshio
November 18-20, 2003 U.S. GLOBEC Georges Bank Sheremet
Lab Experiment
November 18-20, 2003 U.S. GLOBEC Georges Bank Sheremet
Onset of Flow Separation
November 18-20, 2003 U.S. GLOBEC Georges Bank Sheremet
Particle Image Velocimetry
November 18-20, 2003 U.S. GLOBEC Georges Bank Sheremet
Importance of Bottom Drag
• Advective time scale
• Scotian Shelf, Strong tidal dissipation
• Laboratory
November 18-20, 2003 U.S. GLOBEC Georges Bank Sheremet
Conclusions
• Numerical experiments suggest that the system is close to a bimodal state
• Baroclinicity and friction relax potential vorticity constraint and allow the crossover
• Inertia promotes the crossovers and along with baroclinicity affects the position of flow separation
• Tidally modulated bottom drag, especially during winter unstratified conditions