동해에서 저주파 음파전파에 대한 Warm Eddy의 효과

Abstract

It has been known that sound waves in the sea generally propagate under theinfluence of sea surface wave, water depth, sound speed profile, sea floor sediment, etc. In particular, an abrupt change of the sound speed profile with depth in an eddy can greatly affect the sound propagation. Many studies on the sound propagation through eddy and oceanic front have been done in the Gulf Stream, the East Australian Current, the Western Greenland Sea, etc. Eddies are frequently generated at the polar front of the East/Japan Sea near the Korean Peninsula. A warm eddy with diameter of about 200 km is often observedand sound speed profile is frequently affected within about 300 m of water depth at the centre by the eddy in the East/Japan Sea. This sound speed variation can affect long range propagation of sound wave. The characteristics of the low-frequency sound propagation across the observed eddy are investigated by a sound propagation model. As a result, it is ascertained that the low-frequency sound propagation is affected by the warm eddy and thephenomena are dominated in the upper ocean. And the low-frequency sound propagation from the eddy centre to the eddy edge is more affected by the eddy in comparison with the sound propagation from the eddy edge to the eddy centre.