深海上层声速剖面水平非均匀分布对声场会聚区特性预报的影响

Effects of horizontal non-uniform distribution of the upper-layer sound velocity profile on prediction of characteristics of deep-sea convergence zone

针对深海上层声速剖面水平方向弱变化对声场会聚区特征的影响,通过对0°出射声线传播轨迹的分析,提出了只考虑声源及会聚区位置附近声速剖面水平变化实现深海声场会聚区特征准确预报的方法,该方法有助于降低深海声传播调查时声速剖面水平非均匀分布的测量工作量。通过模拟小振幅内波引起深海上层声速剖面水平非均匀变化,对该方法进行了仿真验证。南海声传播试验数据分析表明,当不考虑上层声速剖面的水平非均匀分布时,模型预报的声场会聚区位置及会聚区能量分布与实测结果有一定差异,该差异具有距离累积效应,到第二会聚区时位置累计误差可达3 km,当考虑会聚区宽度内声速剖面水平变化时,模型预报的声场会聚区位置与实测结果非常吻合,第二会聚区位置预报误差小于1 km。

The weak change of the horizontal distribution of the sound velocity profile(SVP) in the deep-sea upper layer will affect the characteristics of the sound field convergence zone(CZ).A method for accurately predicting the characteristics of the deep-sea sound field CZ is proposed by analyzing the propagation track of the outgoing sound rays in the direction of 0°.This method only needs to consider the horizontal variation of the upper-layer SVP near the location of the sound source and CZ,which is helpful to reduce the measurement workload of horizontal non-uniform distribution of SVP in deep-sea sound propagation survey.The method is verified by simulating the horizontal non-uniform distribution of the SVP in the upper layer of the deep sea caused by small amplitude internal wave.The analysis results of the deep-sea measured data in the South China Sea also show that when the horizontal non-uniform distribution of the upper layer SVP is not considered,the location and energy distribution in the CZ predicted by the model is different from the measured results,and the difference has a distance accumulation effect.Because of this effect,the prediction error of the second CZ can reach 3 km.When considering the horizontal variation of the SVP within the CZ width,the characteristics of the CZ predicted by the model are in good agreement with the measured results,and the prediction error of the second CZ is less than 1 km.