Acoustical Physics

, Volume 53, Issue 3, pp 305–312

Transmission of low-frequency sound through the water-to-air interface

Authors

  • O. A. Godin
    • Cooperative Institute for Research in Environmental SciencesUniversity of Colorado at Boulder and NOAA Earth System Research Laboratory
Article

DOI: 10.1134/S1063771007030074

Cite this article as:
Godin, O.A. Acoust. Phys. (2007) 53: 305. doi:10.1134/S1063771007030074

Abstract

L.M. Brekhovskikh revealed and studied the important role played by inhomogeneous waves emitted by a point source when they pass through an interface with a medium in which the velocity of sound is lower, for example, from water to air. This paper studies the energy characteristics of sound emitted into air by an underwater point source. The energy transfer due to inhomogeneous waves is shown to cause the phenomenon of anomalous transparency of the interface for low-frequency sound. The anomalous transparency manifests itself in that the energy flux through the interface increases with decreasing frequency of sound and, at sufficiently low frequencies, almost all of the acoustic energy produced by the underwater source is emitted into air. Conversely, at high frequencies, when the contribution of the inhomogeneous waves becomes negligible, the water-to-air interface is similar to a perfectly reflecting surface and almost all of the acoustic energy produced by the source is emitted into water. The anomalous transparency phenomenon changes the conventional opinion on the possibility of acoustic coupling between points in water and air and on the role played by physical processes evolving in the water column in generating atmospheric acoustic noise.

PACS numbers

43.20.E1 43.28.Dm 43.30.Jx

Copyright information

© Pleiades Publishing, Ltd. 2007