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Waves induced by sources near the ocean surface

Published online by Cambridge University Press:  21 April 2006

Y. P. Guo
Y. P. Guo
Affiliation:
Department of Engineering, University of Cambridge, Trumpington Street, Cambridge CB2 1PZ, UK
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Abstract

The problem of wave generation by sources near the ocean surface is examined. The model is used to deduce that in the ocean, at low frequencies, both sound and surface gravity waves are possibly induced by the same sources. Sound radiation from particular sources is significantly influenced, at low frequencies, by surface waves which themselves are almost unmodified by fluid compressibility. The wave fields and energy levels are calculated analytically in a simple model of point-source excitation, which reveals considerable character. The theory is used to interpret measurements from the real ocean in the case where the source is a finite distribution of surface pressure fluctuations caused by winds. Good consistency is found in both structure and order of magnitude. Our main conclusions are that surface waves and wave-related sound are not necessarily cause and effect; a considerable proportion of the wave-associated underwater sound in the ocean is very likely generated by the same sources that produced the surface waves themselves.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 181 , August 1987 , pp. 293 - 310
Copyright
© 1987 Cambridge University Press

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References

Brekhovskikh, L. M. 1966 Underwater sound waves generated by surface waves in the ocean. Izv. Atmos. Oceanic Phys. 2, 970–980.Google Scholar
Dowling, A. P. & Ffowcs Williams, J. E. 1983 Sound and Sources of Sound. Ellis Horwood.
Finnveden, S. 1987 The boundary condition for a free surface with gravity waves formulated as a locally reacting surface impedance. J. Sound Vib. 112, 575–576.Google Scholar
Isakvich, M. A. & Kur'yanov, B. F.1970 The theory of low frequency noise in the ocean. Sov. Phys. Acoust. 16, 49–58.Google Scholar
Lamb, H. 1932 Hydrodynamics. Cambridge University Press.
Levine, H. 1980 Output of acoustical sources. J. Acoust. Soc. Am. 67, 1935–1946.Google Scholar
Lighthill, M. J. 1978 Waves in Fluids. Cambridge University Press.
Morris, G. B. 1978 Depth dependence of ambient noise in the northeastern Pacific Ocean. J. Acoust. Soc. Am. 64, 581–590.Google Scholar
Nichols, R. H. 1981 Infrasonic ambient ocean noise measurements: Eleuthera. J. Acoust. Soc. Am. 69, 976–981.Google Scholar
Phillips, O. M. 1977 The Dynamics of the Upper Ocean. Cambridge University Press.
Phillips, O. M. 1985 Spectral and statistical properties of the equilibrium range in wind-generated gravity waves. J. Fluid Mech. 156, 505–531.Google Scholar
Snyder, R. L., Dobson, F. W., Elliott, J. A. & Long, R. B. 1981 Array measurements of atmospheric pressure fluctuations above surface gravity waves. J. Fluid Mech. 102, 1–59.Google Scholar
Urick, R. J. 1967 Principles of Underwater Sound. McGraw-Hill.
Watson, G. N. 1966 The Theory of Bessel Functions. Cambridge University Press.