Sensitivity of the underwater sound field in submarine canyons to water column variability

Abstract

The ocean dynamics in the geologically and morphologically complex submarine canyons can have strong spatial and temporal variability due to the presence of internal tides/waves and upwelling currents. Our fundamental research question is what the acoustic effects of these oceanographic processes are in such environments where the sound propagation is also strongly influenced by the seafloor complexity. A simple example showing the joint effects is the bottom reflection of sound that has complicated patterns depending on the shape of canyon seafloor, seabed properties, and acoustic incident angles. Among these factors, the incident angle is the link connecting the acoustic effects of marine geology and physical oceanography. Specifically, the ocean dynamics changes the water column stratification and thus the incident angle of sound onto the seafloor, which explicitly determines the reflection of sound from the complex canyon seafloor. More involved examples using integrated regional ocean and full-field sound propagation models will be shown in the talk, and sensitivity analysis of underwater sound propagation along and across canyons will be performed. [Work supported by the Office of Naval Research.]