Underwater Acoustic Sound Propagations: Climatological Characteristics of Seasonal, Mesoscale, and Submesoscale

The underwater acoustic coastal environment is presented in views of seasonal climatology and potential interactions of sound waves with mesoscale and submesoscale processes are examined. The sound speed profiles (SSPs) are computed from two-/three-dimensional underwater acoustic propagation models and observed conductivity-temperature-depth profiles, and submesoscale realistic numerical model outputs. The density profiles, multivariate regressed with a temporal mean, seasonal basis functions, and a linear trend are translated into the propagation and dissipation of the SSP. Moreover, the density profiles in the cross-shore direction are decomposed into a constant density profile in the cross-shore direction, and density profiles having mesoscale and submesoscale features using a band-pass filter in the frequency domain and wavenumber domain. In this chapter, the analysis method to evaluate the influence of submesoscale and mesoscale oceanic variability on the sound propagation is only presented.