西太平洋一、二岛链间海区声传播的季节因素分析

Analysis of Seasonal Factors to Acoustic Propagation between the Areas of First and Second Island Chains in the Western Pacific Ocean

以分析西太平洋第一、第二岛链间海区在不同季节时的声传播情况为研究目的,利用world ocean atlas 2013(WOA13)季节平均数据和Mackenzie声速经验公式,首先分析该海区声道轴深度和表层声速值的四季分布情况;再利用BELLHOP水声学数值模型,在设定的1 000 Hz声源频率和15°～-15°掠射角情况下,仿真计算选用位置点5 m深度声源的四季声传播情况,研究其规律:四季反转深度由15°N以南的4 900 m以上,降至25°N以北的4 900 m以下,且夏季最深,春秋两季次之,冬季最浅。多数海区可形成汇聚区波导并主要存在于冬秋两季,第一汇聚区位置相对在61～64 km;通常夏季最远,春秋两季次之,冬季最近。在设定的仿真计算条件下声传播覆盖范围有限,需通过其他手段和战术行动改善。

In order to analyze the influence of seasonal factors to acoustic propagation between the first and the second island chain in the Western Pacific Ocean,the average data of WOA13 and the Mackenzie empirical sound speed equation was used for the study.The distribution of values corresponding to sound channel and surface sound speed of the area in four seasons was analyzed at first.Then under the circumstances of given sound source frequency of 1 000 Hz and grazing angle of 15°to-15°,the pattern of acoustic propagation in 4 seasons in 5 m depth at the chosen locations was studied,used BELLHOP hydroacoustics model.As results,it was found that the reverse depth in 4 seasons were more than 4 900 m to south of 15°N,decreasing to less than 4 900 m to north of 25°N,was deepest in summer,shallower in spring and autumn,and shallowest in winter.Most areas could form convergence waveguide in winter and autumn mainly.The span of the first convergence zone was 61 km to 64 km,and was maximal in summer,decreasing in spring and autumn,and reached the minimum in winter.Tactic operations and other methods should be used for improving the limitation of acoustic propagation coverage by the given simulated conditions.