摘要
中层冷水是出现在我国东海西北部和南黄海西部海区的一种特殊海洋现象，其分布规律及形成机制已有较清晰的认识，但这种现象引起的水声传播效应却尚不明确。应用KRAKEN简正波模型对1996—05一处实测中层冷水环境下的声场进行计算与分析，并与均匀声速环境下的声场进行比较，发现声波在冷水层中传播时在较强的陷获作用下能够形成波导型声场，使传播损失相对于常规环境明显减小，对于1kHz的声波2种声场的传播损失差异可达15～20dB。与深海波导不同的是，中层冷水环境引起的浅海波导是特定区域和季节条件下出现的一类特殊现象，其声场特性明显受到海面和海底制约，波导效应引起的声场能量变化与温跃层和逆温层的厚度以及梯度大小有关。
Intermediate cold water （ICW） is known as a special oceanographic phenomenon occurring in the northwestern East China Sea and the western South Yellow Sea. its distribution and formation mechanism have been clearly recognized, but little is known about correlative acoustic effects. Herein, the sound field in an ICW environment measured in 1996-05 is calculate by using the KRAKEN model and then compared with the sound field in a general environment. The results indicate that sound waves can be strongly re-stricted in cold water layer during their propagation and form a shallow-duct sound field, which could evi-dently reduce the transmission loss relative to the general sound field with the difference being 15-20 dB between 2 sound fields with 1 kHz frequency. These findings suggest that the shallow-duct created by ICW should be a distinct effect and the features of the sound field be strongly influenced by the surface and bot-tom features, being very different from the deep-sea duct. The variations of acoustic energy caused by the shallow-duct have more to do with the thickness and gradients of the thermocline and thermal inversion layer.
出处
《海洋科学进展》
CAS
CSCD
北大核心
2014年第1期15-20,共6页
Advances in Marine Science
关键词
中层冷水
逆温层
浅海波导
声场
intermediate cold water （ICW）
thermal inversion layer
shallow-duct
sound field
