Study on Low-Frequency Sound Propagation through a Warm Eddy in The East/Japan Sea by Propagation Model

Abstract

It has been known that sound waves in the sea generally propagate under the influence of sea surface wave, water depth, sound speed profile, and sea floor sediment etc. In particular, an abrupt change of the sound speed profile with depth in an eddy can greately affect the sound propagation. Many studies on the sound propagation through eddies and oceanic fronts have been done in 1980s. Eddies are frequently generated at rhe polar front of the East/Japan Sea near the Korean Peninsula. Warm eddy with diameter of about 200 km is often observed in the East/Japan Sea. Sound speed profile is affected within about 300 m of water depth at a center of the eddy. This variation can affect long-range propagation of underwater sound wave. We perform numerical calculations by using a range-dependent acoustic propagation model for explanation of the experimental results on low-frequency sound propagation across the observed eddy are investigated by the propagation model.1