Modeling the interaction of acoustic and internal wave fields in shallow-water environments

Abstract

Over the past decade, there has been considerable interest in the effect of solitary wave packets on the acoustic field. This talk will present an overview of modeling efforts to describe the interaction of these internal gravity waves with acoustic field propagation in shallow-water waveguides. The emphasis will be on the interaction of solitary wave packets with low-frequency acoustic fields propagating in a continental shelf/slope environment. Topics to be discussed will include both adiabatic and mode-coupling effects, differences between 2-D and 3-D propagation, as well as the influence of wave packets on horizontal array beamforming. Most research to date involves solitary wave propagation over flat bathymetry, but does not address the generation of internal tides over variable bathymetry and their subsequent evolution into wave packets. In this regard, recent nonlinear fluid dynamic simulations of both the generation and propagation of internal tides and wave packets are illustrated and their influence on acoustic propagation briefly addressed. [Work supported by ONR.]