文献类型：期刊文献

英文题名：Analysis of Surface Sound Duct in the Northern Shelf of the South China Sea

作者：Qu, Ke[1,2,3,4];Piao, Shengchun[1,3];Zhou, Jianbo[1,3];Zhu, Fengqin[4]

机构：[1]Harbin Engn Univ, Coll Underwater Acoust Engn, Harbin 150001, Heilongjiang, Peoples R China;[2]Guangdong Ocean Univ, Guangdong Prov Key Lab Coastal Ocean Variat & Dis, Zhanjiang 524088, Peoples R China;[3]Harbin Engn Univ, Acoust Sci & Technol Lab, Harbin 150001, Heilongjiang, Peoples R China;[4]Guangdong Ocean Univ, Coll Elect & Informat Engn, Zhanjiang 524088, Peoples R China

年份：2018

卷号：2018

外文期刊名：SHOCK AND VIBRATION

收录：SCI-EXPANDED(收录号：WOS:000432840500001)、、EI(收录号：20182205261018)、Scopus(收录号：2-s2.0-85047650865)、WOS

基金：This study is supported by the National Natural Science Foundation of China (41406041), the Natural Science Foundation of Guangdong Province (2014A030310256), and the Project of Enhancing School With Innovation of Guangdong Ocean University (GDOU2016050246). The authors would like to acknowledge the data support from "South China Sea and Adjacent Seas Data Center, National Earth System Science Data Sharing Infrastructure, National Science & Technology Infrastructure of China (http://ocean.geodata.cn)."

语种：英文

外文关键词：Temperature - Hydrostatic pressure

外文摘要：The northern shelf of the South China Sea (NSSCS) is characterized by surface low-salinity water due to discharge from the Pearl River. In such an environment, the surface sound duct (SSD) is the most important duct for near-surface sonar applications. Nevertheless, the mechanism of SSD formation is very complicated and is influenced by salinity, temperature at the air-sea interface, and various additional marine phenomena. In this study, an 8-year conductivity-temperature-depth (CTD) profile of the NSSCS was used to analyze the SSD formation. An advanced diagrammatic method is proposed to provide a quantitative analysis of the contribution of salinity, temperature, and hydrostatic pressure on SSD formation. Large salinity gradient (0.25 psu/m) was shown to play a crucial role in SSD formation when a mixed layer exists. As representative examples, the sea under cold surges, typhoon genesis, and low-salinity lenses were studied. Conversely, the absence of SSDs in low-salinity water was also observed in upwelling regions. This study further showed that highly negative temperature gradients affect SSD formation even in low-salinity water. Furthermore, although the duct depth of a low-salinity SSD is usually less than 10 meters, it still can serve as an effective duct for acoustic propagation.