Acoustic hindcasts of array performance using a combination of submesoscale hydrodyamic and acoustic models.

Abstract

It is well known that submesoscale ocean processes such as nonlinear internal gravity waves can have a significant effect on both the amplitude and the phase of an acoustic field propagating through this type of ocean environment. We report here on hindcasts computed with a numerical model combination consisting of a submesoscale hydrodynamic solver to compute a set of three‐dimensional (3‐D) environmental (sound speed) volumes evolving in time and a 3‐D wide‐angle parabolic equation code for acoustic field computation within each environmental volume. The data set was chosen from the ASIAEX 2001 experiment in the South China Sea, during a period of strong internal wave activity. A nonlinear wave packet was simulated propagating up the shelf and passing through both the acoustic source and receiver positions. The hindcasts computed the time evolving beam response on a horizontal array, located approximately 19 km from a 300 Hz low‐frequency modulat source. Comparison of experimental and modeled beamformed...