Acoustic wave propagation across an oceanic front

Abstract

The parabolic approximation to the wave equation (Tappert, 1974) is employed to compute the two-dimensional low-frequency underwater acoustic field in a surface duct interrupted by an oceanic front. The sound speed along the propagation path was calculated from almost synoptic temperature profiles obtained from a towed thermistor chain (Cummins, 1972). A comparison is made between the calculated and the observed acoustic field at two frequencies and five receiver depths. The numerical technique is then used to calculate the acoustic field for other source-receiver geometries and to establish the importance of horizontal variability in the sound-speed profiles and look into the effects of the oceanic front upon acoustic wave propagation.