Comparison of two and three spatial dimensional solutions of a parabolic approximation of the wave equation at ocean-basin scales in the presence of internal waves: 200–250 Hz.

Abstract

Numerical solutions are given for a parabolic approximation to the acoustic wave equation at 200 and 250 Hz in two and three spatial dimensions to determine if azimuthal coupling in the horizontal coordinate significantly affects horizontal correlation in the presence of internal gravity waves in the sea. Coupling is a small effect at distances of 4000 km or less. This implies that accurate solutions are possible using computations from uncoupled vertical slices. Shapes of horizontal correlation are not far from shapes given by several theories. Estimates of horizontal correlation at 4000 km and 200 and 250 Hz are about 0.4 and 0.3 km, respectively. [Work supported by the Office of Naval Research Contract Nos. N00014-06-C-0031 and N00014-10-C-0480 and by a grant of computer time from the DOD High Performance Computing Modernization Program at the Naval Oceanographic Office.]