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On the formation of nonlinear internal waves from the gravitational collapse of mixed regions in two and three dimensions

Published online by Cambridge University Press:  19 April 2006

T. Maxworthy
T. Maxworthy
Affiliation:
Departments of Mechanical and Aerospace Engineering, University of Southern California, Los Angeles, California 90007
Also Jet Propulsion Laboratory, Pasadena, California and the Australian National University, Canberra, Australia.
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Abstract

We show how trains of nonlinear, dispersive wavesIn some of the caaes to be described these are in fact sequences of solitary waves which are ordered by amplitude and which separate in space, as they propagate. In other cases the wave amplitude decreases as the wave propagates, but since the essential balance is between nonlinear steepening and frequency dispersion we feel justified in using the adjective ‘solitary’ to describe them though they violate the clessical description of such waves. can be produced by allowing a region of mixed fluid, with a potential energy greater than its surroundings, to collapse towards its equilibrium state. The number of waves and their amplitude depend on the properties of the mixed region and of the ambient stratification. Three different geometrical configurations have been chosen and while each gives qualitatively the same results the form taken by the generated waves and the final equilibrium shape of the mixed region depend critically on these geometrical factors. We relate the internal waves produced by this mechanism to waves produced in natural systems and show that our observations support at least one possible explanation for those found in the oceans and planetary atmospheres.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 96 , Issue 1 , 16 January 1980 , pp. 47 - 64
Copyright
© 1980 Cambridge University Press

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