Abstract

Data from a section of eleven current meters oriented across-isobaths at three locations on Georges Bank were examined. On the bank, the M2 tidal currents were barotropic and were in close agreement with the Greenberg (1983) numerical model of the Gulf of Maine. On the slope, the M2 tidal current contained 70° phase shifts for 35 m changes in depth. The results from the model were used to separate currents due to the internal and surface tides. It was found that amplitude of the tidal velocities associated with the baroclinic component of the internal tide were as large as for the estimated barotropic tidal velocities. The eddy and mean heat fluxes off the bank were calculated. The depth-averaged heat flux due to the mean currents was statistically zero. The eddy heat flux on the slope was significant and was in a direction consistent with a transport of scalar properties on to the bank. A horizontal diffusion coefficient of 290 m2/s was calculated. The maximum eddy flux occurred immediately below the thermocline on the bank slope at a depth of large temperature inversions. It is suggested that a breaking internal tide plays a large role in determining across-isobath scalar transports.

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