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Kelvin wave hydraulic control induced by interactions between vortices and topography

Published online by Cambridge University Press:  11 October 2011

Andrew McC. Hogg*
Affiliation:
Research School of Earth Sciences, The Australian National University, Canberra, ACT 0200, Australia
William K. Dewar
Affiliation:
Department of Oceanography, Florida State University, Tallahassee, FL 32306-4320, USA
Pavel Berloff
Affiliation:
Department of Mathematics and Grantham Institute for Climate Change, Imperial College, London SW7 2AZ, UK
Marshall L. Ward
Affiliation:
Research School of Earth Sciences, The Australian National University, Canberra, ACT 0200, Australia
*
Email address for correspondence: Andy.Hogg@anu.edu.au

Abstract

The interaction of a dipolar vortex with topography is examined using a combination of analytical solutions and idealized numerical models. It is shown that an anticyclonic vortex may generate along-topography flow with sufficient speeds to excite hydraulic control with respect to local Kelvin waves. A critical condition for Kelvin wave hydraulic control is found for the simplest case of a 1.5-layer shallow water model. It is proposed that in the continuously stratified case this mechanism may allow an interaction between low mode vortices and higher mode Kelvin waves, thereby generating rapidly converging isopycnals and hydraulic jumps. Thus, Kelvin wave hydraulic control may contribute to the flux of energy from mesoscale to smaller, unbalanced, scales of motion in the ocean.

Type
Papers
Copyright
Copyright © Cambridge University Press 2011

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