Quantifying three-dimensional effects on sound propagation near the New England Sea Mount Chain using ray-tracing

This study investigates the impact of three-dimensional (3-D) bathymetry and sound speed variability on sound propagation, utilizing 3-D ray tracing compared to simple two-dimensional ray tracing (Nx2-D) within the New England seamount chain, focusing on the Atlantis II seamount area. The research has three main objectives. First, it examines the differences between 3-D and 2-D acoustic propagation modeling of bathymetric reflections. Second, it evaluates the impact of physical oceanographic effects on 3-D versus 2-D acoustic modeling, employing a high-resolution regional ocean circulation model with a horizontal resolution of 1 km and 100 terrain-following vertical layers. Third, it compares the modeled acoustic propagation to experimental data collected by a surface autonomous vehicle (wave glider) fully instruments for measuring local physical ocean variables (e.g., CTD data) and equipped with a compact tetrahedron hydrophone array (capable of profiling the water column from ∼10 to ∼150m) which recorded low and mid-frequency transmissions from moored acoustic sources deployed near Atlantis II seamount. The need for full 3-D ray-tracing modeling (instead of using simpler Nx2-D simulations) for accurately predicting shadow zones and understanding regional acoustic propagation paths in areas with rapid and diverse bathymetric changes, such as isolated seamounts, will be quantified.