Topographic instability and multiple equilibria on an f-plane |
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| Authors: | P F Linden |
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| Institution: | Department of Applied Mathematics and Theoretical Physics , University of Cambridge , Silver Street, Cambridge CB39EW, U.K |
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| Abstract: | Abstract The flow of a two-layer flow in a rotating channel on an f-plane over topography with sinusoidal variation of height in a direction parallel to the flow is investigated. When the two layers flow in opposite directions a resonance is found when the topographic scale matches the free mode of the system. We examine the stability of the forced mode in the vicinity of this resonance by means of a perturbation expansion of the topographic height. Both subresonant and super-resonant instabilities are found and their equilibration is examined. For small values of the dissipation multiple equilibria are found. The topographic drag releases potential energy even when the flow is baroclinically stable. |
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| Keywords: | Solitons solitary waves nonlinear waves coastal oceanography internal waves internal tides |
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