Sound field transverse coherence length estimation in shallow water in the presence of background internal waves

Using the theory of adiabatic modes, the problem of low-frequency sound field transverse coherence length estimation is considered analytically for a shallow-water waveguide in the presence of background internal waves. The Garrett-Munk style spectrum modified for a shallow-water environment is exploited to describe vertical displacements of the liquid. Internal wave field is assumed to be isotropic. Explicit dependencies of the coherence length on the source range, sound frequency, energy density of internal waves, and other parameters are obtained. Qualitative and quantitative agreement between analytical estimates and numerical simulation results is demonstrated. The comparison of the transverse coherence length estimates with the experimental data is performed.