ABSTRACT
Mathematical models of noise in the ocean can be segregated into two categories: ambient-noise models and beam-noise statistics models. Ambient-noise models predict the mean levels sensed by an acoustical receiver when the noise sources include surface weather, biologics, and commercial activities such as shipping and oil drilling. Ambient-noise models treat noise sources as variable densities distributed over large areas. Consequently, the transmission loss calculations in ambient-noise models can be range-averaged. Alternatively, beam-noise statistics models treat noise sources as discrete sources and thus require point-to-point representations of transmission loss. Sadowski et al. reviewed regression formulas appropriate for the estimation of average ambient-noise spectra below 100 kHz including noise sources arising from ocean turbulence, shipping traffic, surface weather, and molecular agitation. The theory behind this kind of modeling, in addition to some observational data on the density of shipping traffic in the North Atlantic, has been described by Dyer, among others.
