| Wen Hongtao,Wang Ning,Yang Yanming,Ruan Hailin,Xu Dewei. 2020. Effects of islands and downslope seafloors on underwater noise in the northern South China Sea during a typhoon. Acta Oceanologica Sinica, 42(5):87－95 |
| Effects of islands and downslope seafloors on underwater noise in the northern South China Sea during a typhoon |
| 台风期间南海北部岛礁及下坡海底对水下噪声的影响研究 |
| Received:March 28, 2019 |
| DOI：10.1007/s13131-020-1566-4 |
| Key words:underwater noise typhoon downslope enhancement the northern South China Sea |
| 中文关键词: 水下噪声 台风 下坡增强效应 南海北部 |
| 基金项目: |
| Author Name | Affiliation | E-mail | | Wen Hongtao | College of Information Science and Technology, Ocean University of China, Qingdao 266100, China
Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China | | | Wang Ning | College of Information Science and Technology, Ocean University of China, Qingdao 266100, China | | | Yang Yanming | Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China | yangyanming@tio.org.cn | | Ruan Hailin | Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China | | | Xu Dewei | Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China | |
|
| Hits: 1007 |
| Download times: 711 |
| Abstract: |
| The correlation of ambient noise with wind speed, and the depth dependence of ambient noise are both investigated, where the ocean noise data were recorded by a vertical line array in the northern South China Sea. It is shown that the correlation coefficients increase with increasing hydrophone depth during typhoon periods when the frequency ≥ 250 Hz, which opposes the generally accepted knowledge that the correlation coefficients of noise level and wind speed decrease with increasing depth during non-typhoon periods. Particularly at frequencies of 250 Hz, 315 Hz and 400 Hz, the correlation coefficients increase by more than 0.05 at depths ranging from 155 m to 875 m. At the three frequencies, the average noise levels also increase with increasing depth during typhoon periods. It is suggested that these differences are attributed to the wind-generated noise in shallow waters and the effect of “downslope enhancement” to sound propagation. During typhoon periods, the surf breaking and surf beat upon the shores and reefs are strengthened, and the source levels are increased. The wind-generated noise in shallow waters interacts with the downslope sea floor, with the noise-depth distribution changed by a “downslope enhancement” effect promoting noise propagation. |
| 中文摘要: |
| 利用垂直水听器阵测量的南海北部海洋环境噪声数据，研究了环境噪声与风速的相关性、环境噪声的深度依赖特性。研究表明，当频率≥ 250 Hz时，在非台风期间，环境噪声与风速的相关系数随水听器接收深度的增大而减小，但在台风期间，相关系数却随接收深度的增大而增大。特别在250Hz、315Hz和400Hz三个频率，相关系数在155m~875m的深度上增大超过0.05。在这三个频率点，台风期间的平均噪声级也随水听器接收深度的增大而增大。研究认为，相关系数和噪声级大小在台风和非台风期间随接收深度的变化趋势的不同，应归因于浅水的风生噪声源和声传播的下坡增强效应。在台风期间，浅水的风浪破碎、风浪拍打海岸和岛礁的作用增强，风生噪声源级增大，浅水的风生噪声与声传播路径上的下坡海底相互作用，在声传播过程中形成“下坡增强”效应，最终影响了测量海域的环境噪声及其深度分布。 |
|
HTML
View Full Text
View/Add Comment Download reader |
| Close |
|
|
|
