Study of underwater sound propagation in the continental shelf of the Mid Atlantic Bight with integrated physical oceanographic and acoustic models.

Abstract

Underwater sound propagation in continental shelf regions is influenced by many physical oceanographic and geological features. With a data‐assimilated ocean model, the physical oceanographic (PO) influences can be taken into account in a sound propagation model. This talk presents an integrated modeling framework with the regional ocean modeling system (ROMS) and parabolic‐equation (PE) based sound propagation models. Technical issues on the model integration will be addressed, and the final product is implemented in the continental shelf of the Mid Atlantic Bight. The water column variability caused by shelfbreak fronts and linear internal waves is captured in the ocean model and directed into the acoustic model. The sound propagation effects by realistic shelfbreak fronts, frontal intrusions, and linear internal waves can be studied. In considering the geological influences on both PO and acoustic fields, this integrated model is implemented over the Hudson Canyon area. Three dimensional sound focusing due to the canyon topography is observed, and the temporal variability of such focusing patterns caused by the changes in the PO field is also quantified. In conclusion, by combining the state‐of‐the‐art ocean and acoustic models, numerical simulations of underwater sound propagation are moving forward and toward more reality.