Observations and analysis of environment and acous

Authors: GuangBing Yang LianGang Lü YeLi Yuan Ying Jiang ZongWei Liu ChunMei Yang HongNing Liu Zhao Chen

Publish Date: 2015/07/04

Volume: 58, Issue: 12, Pages: 2260-2270

PDF Link

Abstract

In order to investigate the environment and acoustic filed change induced by typhoon in shallow sea we conducted two experiments just before and after the passage of typhoon Damrey which is the strongest to affect the area north of the Yangtze River since 1949 in the Yellow sea in 2012 The data show that the temperature of the whole water column increases dramatically except the sea surface layer after the passage of Damrey while the salinity decreases obviously The thermocline deepens and weakens which leads to a change of internal wave activity The transmission losses TL of the two experiments show that the environment change induced by typhoon can increase the TL as large as 8 dB at a distance of 92 km and depth of 15 m The scintillation index SI of the sound intensity is simulated to estimate the change of the effect of internal wave activity on acoustic field showing that the SI decreases to a half after the typhoon’s passage The normal mode structures of the two experiments are also significantly different due to the thermocline changes In addition the signal arrives earlier after the typhoon’s passage due to the water temperature increase

Keywords: