Vertical coherence of low‐frequency sound waves propagating through a fluctuating ocean

Abstract

Low‐frequency sound waves propagating over large distances in the ocean exhibit significant scattering due to internal waves. Studies of low‐frequency sound propagation through a fluctuating ocean are important for many practical concerns such as communication, acoustic tomography, and source detection, ranging, and recognition. In a recent work [A. G. Voronovich and V. E. Ostashev, J. Acoust. Soc. Am. 63, 1406–1419 (2006)] a 3‐D modal theory of sound propagation through a fluctuating ocean was developed. Closed equations for the first two statistical moments of a sound field were derived using the Chernov method and assuming that the spectrum of internal waves is given by the Garret‐Munk spectrum. In the present paper, we numerically solve the derived equation for the second moment. The results obtained are used to study the dependence of the vertical coherence of a sound field on several parameters of the problem: range, frequency, source and receiver depths, and parameters that characterize the Garret‐...