浅海内波对环境噪声水平方向凹槽的影响  

Effect of internal wave on horizontal notch of ambient noise in shallow water

作　　者：江鹏飞[1] 衣雪娟[1] 林建恒[1] 蒋国健[1] 

机构地区：[1]中国科学院声学研究所北海研究站,山东青岛266023

出　　处：《声学技术》2011年第5期407-411,共5页Technical Acoustics

基　　金：国家自然科学基金资助项目(10974219)

摘　　要：典型夏季海洋环境噪声垂直指向性水平方向经常出现一显著凹槽。采用三维声速场海洋环境噪声理论模型,分析了各阶简正波对垂直指向性的贡献,指出不同阶简正波的贡献不同,高阶简正波是形成水平方向凹槽的主因,低阶简正波起填补环凹槽的主要作用,无内波时海面噪声源激发低号简正波的能量较低,填补能力较差,水平凹槽显著;内波活动期,内波改变了声信号的传播路径,引起不同阶简正波耦合,低号简正波能量增强,其填补噪声水平凹槽的作用明显加强,高阶简正波能量减少,凹槽变浅。还探讨了凹槽填补程度与内波强度之间的关系,以及有内波时环境噪声垂直指向性随时间的变化。Researches indicate that a visible notch often appears in the horizontal direction of the vertical noise direc-tionality in typical summer sea.In this paper,the three-dimensional sound speed profile-ambient noise model is adopted to analyze the contribution of every mode to the vertical directionality,and the differences of contribution are pointed out.The high order modes are the main cause to the noise notch,while the low order modes can fill the notch.When internal waves are absent,the low order modes are weakly excited,the ＇fill＇ ability is feeble and the notch is visible.In the internal wave field,internal waves change the sound signal propagation paths to cause the conversion between different modes.Low order modes are strengthened and higher order modes are weaken,the notch becomes shallow.Besides,the relation of the ＇fill＇ degree with the strength of internal waves and the variation of the vertical directionality with time are discussed.

关 键 词：浅海内波 三维环境噪声模型 环境噪声指向性 噪声水平凹槽 

分 类 号：TB556[理学—物理]