Research on the Response of the Acoustic Structure in the Upper Ocean during Hurricane Transit

Communication and target detection in underwater acoustics depend significantly on the acoustic structure of the upper ocean, influenced by dispersion processes occurring within it. This study analyzed the hydrological characteristics and sound velocity structures of the upper ocean before, during, and after three consecutive hurricanes in 2017 in the North Atlantic, as well as the acoustic velocity structure response of the upper ocean during transit. Data from hurricanes and underwater glider observations provided by the National Oceanic and Atmospheric Administration (NOAA) were analyzed to determine the distance between the hurricane and the glider. Hydrological data was utilized to compute the sound velocity profiles and time series of acoustic characteristics over the upper ocean before, during, and after hurricane transit. The acoustic structure of the upper ocean altered when the hurricane was 2000 km from the glider, revealing variations depending on whether the hurricane approached from the left (left-side hurricane) or the right (right-side hurricane). The findings indicated a consistent sound profile above the primary and deeper main sound channel, with sound intensity varying—stronger on the left side of the hurricane and weaker on the right side. The analysis revealed that the left hurricane experienced an increase in positive gradient intensity from roughly 0.0228 s -1 to 0.092 s -1 , while the right hurricane exhibited a decrease in amplitude from approximately 0.0016 s -1 to 0.0161 s -1 .