Sound field computations in the Bay of Bengal using parabolic equation method

Abstract

Effect of the cold core eddy in the Bay of Bengal on acoustic propagation was analysed by parabolic equation (PE) method. Source depth, frequency and propagation range considered respectively for the two numerical experiments are 150 m, 400 Hz, 650 km (case i) and 1000 m, 70 Hz, 5000 km (case ii). Acoustic intensity levels varied from -20 to -35 dB in the upper 500 m (case i). In the presence of the eddy, isolines exhibited deviations between 250 and 500 km range extending from 100 m to the abyssal region. Maximum insonified region is present in the vicinity of the channel axis depth which showed variations from 800 to 1500 m in case ii.