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The reflexion of internal/inertial waves from bumpy surfaces

Published online by Cambridge University Press:  29 March 2006

P. G. Baines
Affiliation:
Department of Meteorology, Massachusetts Institute of Technology, Cambridge, Massachusetts, U.S.A.

Abstract

When internal and/or inertial waves reflect from a smooth surface which is not plane, there is in general some energy flux which is ‘back-reflected’ in the opposite direction to that of the incident energy flux (in addition to that ‘transmitted’ in the direction of the reflected rays), provided only that the incident wavelength is sufficiently large in comparison with the length scales of the reflecting surface. The reflected wave motion due to an incident plane wave is governed by a Fredholm integral equation whose kernel depends on the form of the reflecting surface. Some specific examples are discussed, and the special case of the ‘linearized boundary’ is considered in detail. For an incoming plane wave incident on a sinusoidally varying surface of sufficiently small amplitude, in addition to the main reflected wave two new waves are generated whose wave-numbers are the sum and difference respectively of those of the surface perturbations and the incident wave. If the incident wave-number is the smaller, the difference wave is back-reflected.

Type
Research Article
Copyright
© 1971 Cambridge University Press

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References

Baines, P. G. 1969 Ph.D. Thesis, University of Cambridge.
Barcilon, V. & Bleistein, N. 1969a Scattering of inertial waves in a rotating fluid. Studies in Appl. Math. 48, 91.Google Scholar
Barcilon, V. & Bleistein, N. 1969b Scattering of inertial waves by smooth convex cylinders. Studies in Appl. Math. 48, 351.Google Scholar
Carrier, G. F., Krook, M. & Pearson, C. E. 1966 Functions of a Complex Variable. McGraw-Hill.
Cox, C. S. & Sandstrom, H. 1962 Coupling of surface and internal waves in water of variable depth. Oceanog. Soc. Japan, 20th Anniv. Vol.Google Scholar
Eckart, C. 1960 Hydrodynamics of Oceans and Atmospheres. Pergamon.
Greenspan, H. P. 1968 The Theory of Rotating Fluids. Cambridge University Press.
Hendershott, M. 1968 Inertial oscillations of tidal period. Scripps Institution Oceanog. Report Ref. 68–12.Google Scholar
Hurley, D. G. 1970 J. Fluid Mech. 43, 97.
Keller, J. B. & Mow, Van C. 1969 Internal wave propagation in an inhomogeneous fluid of non-uniform depth J. Fluid Mech. 38, 365.Google Scholar
Lamb, H. 1945 Hydrodynamics. Dover.
Larsen, L. H. 1969 Internal waves incident on a knife edge barrier Deep Sea Res. 16, 411.Google Scholar
Lighthill, M. J. 1958 Fourier Analysis and Generalized Functions. Cambridge University Press.
Lighthill, M. J. 1965 Group velocity J. Inst. Math. Applics. 1, 1.Google Scholar
Lighthill, M. J. 1967 On waves generated in dispersive systems by travelling forcing effects, with applications to the dynamics of rotating fluids J. Fluid Mech. 27, 725.Google Scholar
Longuet-Higgins, M. S. 1969 On the reflexion of wave characteristics from rough surfaces J. Fluid Mech. 37, 231.Google Scholar
Morse, P. M. & Feshbach, H. 1953 Methods of Theoretical Physics, Parts I and II. McGraw-Hill.
Phillips, O. M. 1963 Energy transfer in rotating fluids by reflection of inertial waves Phys. Fluids, 6, 513.Google Scholar
Phillips, O. M. 1966 Dynamics of the Upper Ocean. Cambridge University Press.
Rattray, M., Dworski, J. G. & Kovala, P. E. 1969 Generation of long internal waves at the continental slope. Deep Sea Res. 16 (Supplement), 179.Google Scholar
Robinson, R. M. 1969 The effects of a vertical barrier on internal waves Deep Sea Res. 16, 421.Google Scholar
Sandstrom, H. 1966 Ph.D. Thesis, University of California at San Diego.