西北太平洋副热带模态水区域声传播特性  

Sound propagation properties in the subtropical mode water in the Northwest Pacific Ocean

作　　者：毕思昭 彭朝晖[1] 王光旭[1] 张灵珊 BI Sizhao;PENG Zhaohui;WANG Guangxu;ZHANG Lingshan(State Key Laboratory of Acoustics,Institute of Acoustics,Chinese Academy of Sciences,Beijing 100190,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院声学研究所声场声信息国家重点实验室,北京100190 [2]中国科学院大学,北京100049

出　　处：《应用声学》2024年第2期252-261,共10页Journal of Applied Acoustics

基　　金：国家重点研发计划资助项目(2021YFF0501200);国家自然科学基金项目(11774374)。

摘　　要：西北太平洋副热带模态水是在西北太平洋夏季出现的温跃层中温度、盐度和密度具有垂向均一性的水团。由于西北太平洋副热带模态水的存在,深海声速剖面呈现出双跃层结构,对深海远程声传播产生较大的影响。该文对比分析了西北太平洋副热带模态水区域夏冬两季典型声速剖面环境下的声传播规律。分析结果表明,夏季声速剖面环境下,声源位于浅层声道宽度内时,声传播为浅层声道的类深海声道传播与会聚区传播的复合形式。掠射角较小的声线被限制于浅层声道中,增加了会聚区内的到达结构,并且增强了在影区的声能量,在第二影区内的传播损失比冬季声速剖面环境下最多低近60 dB。推导了浅层声道的截止频率的近似表达式,分析结果表明,截止频率主要由浅层声道的宽度和正梯度段的声速差值决定,夏季西北太平洋副热带模态水区域浅层声道截止频率主要集中在100 Hz左右。The subtropical mode water(STMW)in Northwest Pacific Ocean is a water mass with vertical homogeneity of temperature,salinity and density in the thermocline,which occurs in the summer in the Northwest Pacific Ocean.Due to the presence of STMW,the deep-sea sound speed profile shows a double thermocline structure,which has a strong impact on the deep-sea long-range sound propagation.In this paper,we compare and analyze the sound propagation patterns of typical sound speed profiles in STMW region in summer and winter.According to the results of this analysis,the sound propagation is a combination of similar SOFAR channel propagation and convergence zone propagation in the shallow sound channel under the summer sound speed profile environment.The rays with smaller grazing angles are confined in the shallow channel,increasing the arrival structure in the convergence zone and enhancing the sound energy in the shadow zone,the transmission loss in the second shadow zone is at most nearly 60 dB less than that in the winter sound speed profile environment.This paper provides an approximate expression for the cutoff frequency of the shallow channel,and the results of the analysis show that the cutoff frequency is primarily determined by the width of the shallow channel and the difference of sound speed in the positive gradient section.The cut-off frequency of the shallow channel in the STMW region in summer is primarily around 100 Hz.

关 键 词：副热带模态水 会聚区 到达结构 截止频率 

分 类 号：O427.1[理学—声学]