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The propagation of a Kelvin wave around a bend in a channel

Published online by Cambridge University Press:  21 April 2006

A. J. Webb
Affiliation:
Department of Oceanography, University of British Colombia, 6270 University Blvd., Vancouver, B.C. V6T 1W5, Canada
S. Pond
Affiliation:
Department of Oceanography, University of British Colombia, 6270 University Blvd., Vancouver, B.C. V6T 1W5, Canada

Abstract

The question is addressed of how much energy is reflected when a Kelvin wave propagating along a straight channel hits a bend. The solution is expressed as a truncated series of Kelvin waves and several evanescent cross-channel Poincaré modes. The bend acts as a diffraction grating – for bends of certain angles there is complete transmission and between these angles there are lobes of reflection. The width of the lobes of the diffraction pattern is directly proportional to the wavelength of the incident Kelvin wave, as in optics, electromagnetism, etc. The effect of changing the inside radius of the bend is also examined. The reflection of energy is generally small unless the Poincaré modes are nearly propagating.

Type
Research Article
Copyright
© 1986 Cambridge University Press

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