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Detailed Reference Information |
Zhang, X., Boyer, D.L., Pérenne, N. and Renouard, D.P. (1996). Mean flow generation along a sloping region in a rotating homogeneous fluid. Journal of Geophysical Research 101: doi: 10.1029/96JC02834. issn: 0148-0227. |
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The mean flow generated by an oscillatory (tidal) current normal to a long sloping region of constant cross section and finite height in a rotating homogeneous fluid is investigated analytically and by laboratory experiments. The geometry is characterized by constant fluid depths hs and hd in the shallow (shelf) and deep regions, respectively, with the sloping region between being smooth and having a characteristic width L. This physical system is characterized by the temporal Rossby number Rot=ω/f, the Ekman number E, the geometric parameters hs/hd and hs/L, and the normalized tidal excursion as/L (or, alternatively, the Rossby number); here ω is the forcing frequency of the oscillatory current, f is the Coriolis parameter, and as is the characteristic tidal excursion. The analysis assumes Rot~O(1), E≪1, hs/L≪O(1), (hd-hs)/hd~O(1) (i.e., finite amplitude topography), and as/L~O(1) (i.e., finite amplitude tidal excursions). The analysis is based upon a spectral method <Zimmerman, 1978> and predicts mean flows along the depth contours of the topography with the shallow region on the right, facing downstream, for vertically upward, or northern hemisphere, rotation. The theoretical approaches used by other investigators using different frictional parameterizations for infinitesimal tidal excursions are also presented. The laboratory experiments were conducted in circular rotating test cells of 1.8 and 13.0 m diameters in which continuous annular topographies of constant cross section were installed along the tank peripheries. The various theories were in qualitative support of the laboratory observations with respect to (1) mean flow direction, (2) location of most intense currents, and (3) dependence on the principal system parameters. Owing to the very small velocities associated with the mean flows generated and the inherent errors of the experiments, quantitative comparison could not be conclusive. Predictions from the various theories give reasonable estimates of such quantities as mean Lagrangian displacements and Eulerian surface transports. ¿ American Geophysical Union 1996 |
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Abstract |
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Keywords
Oceanography, General, Continental shelf processes, Oceanography, General, Analytical modeling, Oceanography, Physical, Coriolis effects, Oceanography, Physical, Currents |
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Publisher
American Geophysical Union 2000 Florida Avenue N.W. Washington, D.C. 20009-1277 USA 1-202-462-6900 1-202-328-0566 service@agu.org |
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