Concurrent physical and acoustical observations of the upper-ocean near Atlantis II seamount using Wave Gliders

The rapid evolution of the physical properties of the upper ocean expected in regions with strong submesoscale features can lead to complex acoustic propagation effects. In spring 2023, an autonomous surface vehicle (LRI Wave Glider) was outfitted with a suite of oceanography and acoustic equipment and deployed in the Gulf Stream in a region located over the New England Seamounts, allowing an opportunity to study how the physical variability can affect the speed of sound and ambient soundscape. In August 2024, three more Wave Gliders were deployed in the same area. The vehicles, using GPS and time-synchronized equipment, were able to collect ambient acoustic data on a four-element hydrophone array, as well as local physical properties (e.g. CTD data, wind speed, and ADCP current data) that could affect the acoustic recordings during long term missions above and around the Atlantis II seamount. Two low frequency sources of opportunity were also able to be recorded over long distances, with noise level varying with vehicle position, allowing an understanding of acoustic propagation paths in this area. These long-term measurements demonstrate the unique capability of an autonomous surface vehicle for making wide-range acoustic surveys.