南海东沙海域线性内波引起的声场统计特性  

Sound field statistical characteristics caused by linear internal waves in Dongsha sea area of the South China Sea

作　　者：张青青 李整林[1] 任云[1] 秦继兴[1] 彭朝晖[1] ZHANG Qingqing;LI Zhenglin;REN Yun;QIN Jixing;PENG Zhaohui(State Key Laboratory of Acoustics,Institute of Acoustics,Chinese Academy of Sciences,Beijing 100190;University of Chinese Academy of Sciences,Beijing 100049)

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：《声学学报》2022年第2期198-209,共12页Acta Acustica

基　　金：国家自然科学基金项目(11874061);中国科学院青年创新促进会资助。

摘　　要：海洋内波对声传播及水声探测具有重要影响。利用南海东沙附近海域一次低频声传播起伏实验同步获取的声学与水文观测数据,从水文连续观测数据中提取了内波特征参数,验证了修正线性内波频谱公式,用蒙特卡洛方法统计分析了存在线性内波条件下的声场起伏特性,并用射线理论解释了声源与跃层相对位置对声场起伏的影响机理。结果表明:随着频率、平均能流密度和收发距离的增加,最大概率传播损失(TL)增大;受线性内波活动的影响,与“上发下收”相比,“下发下收”情况下传播损失的概率分布更发散;随着收发距离的增加,内波的累积效果更加显著,在“下发下收”情况下,40 km处传播损失概率分布最大可增加至8 dB;在负跃层环境下,内波的扰动更有利于声线穿越温跃层。The ocean internal wave has an important influence on sound propagation and underwater acoustic detection.The characteristic parameters and the spectrums of internal waves are analyzed extracted from the ocean environment measurements of a shallow-water experiment conducted in the northern South China Sea.The Monte Carlo method is applied to investigate the influences of the random linear internal waves on Transmission Loss(TL)in the shallow water.The influence mechanism of the relative position of the source and the thermocline on the fluctuation is explained by the ray theory.It is shown that maximal probabilities of the TLs are increased,and the probability distributions of TLs are more dispersive with the increase of the source frequency,the average energy flow density of linear internal waves and the ranges.When the source is located below the thermocline,the probability distributions of TLs are more dispersive than the case that the source is located above the thermocline.The cumulative effect of the linear internal waves is more significant with the increase of the ranges.The TL probability of TLs can be increased by 8 dB at 40 km when the source is located below the thermocline.Sound rays pass through the thermocline more easily in a thermocline environment when the internal waves are disturbed.

关 键 词：传播损失 概率分布 水声探测 海洋内波 射线理论 最大概率 相对位置 声场起伏 

分 类 号：P714[天文地球—海洋科学]