Effect of Internal Solitary Waves on Underwater Acoustic Propagation

Abstract

A B S T R A C TInternal solitary waves (ISWs) were observed on 07:52-09:36 GMT July 30, 2005, in the Philippine Sea near Taiwan from high-resolution temperature sampling. The effect of ISWs on acoustic propagation was identified using the Navy's Comprehensive Acoustic Simulation System through comparison between rangeindependent and range-dependent sound speed profiles. The ISWs enhance the sound propagation slightly (0-3 dB) in near-range, weaken or enhance the sound propagation (−20 to 20 dB) evidently in midrange, and always weaken the sound propagation (up to −20 dB) in far range. The ISW's effect on the acoustic propagation varies with sound frequency and sound source depth. This work provides a methodology to anticipate possible errors in transmission loss estimation in an operational framework, if no further additional data are available.