基于WOA18的西北太平洋第一、二岛链间声速特征分析

Analysis of sound speed characteristics between the first and second island chains in the Northwest Pacific Ocean

本文基于WOA18温盐剖面数据集,利用声速经验公式计算了西北太平洋第一、二岛链间海区的声速剖面,研究了声速特征信息的诊断方法。通过提取声跃层、声道轴等声速特征信息,分别对表面声速、声跃层、声道轴进行分析,统计表面声速、声跃层和声道轴在各个季节的分布情况,得到了研究海区不同声学要素的季节变化特征。结果表明,表面声速主要在1520~1540 m/s区间变化,等值线基本与纬线平行,呈现出自低纬向高纬递减的趋势,声速值随季节变化较大;声跃层平均位置在低纬海区和高纬海区的差异较大,大约在100~650 m区域,低纬海区的声跃层受季节变化影响小,高纬海区的声跃层受季节变化影响大;声道轴深度基本在800 m以深区域,总体上呈现南北深、中间浅的分布态势且四季变化幅度较小。

This paper mainly calculates the sound speed profile of the areas between the first and second island chains in the Northwest Pacific Ocean based on the WOA18 temperature and salinity profile data set.It uses the experiential equation of sound speed and studies the diagnostic method of sound speed characteristic parameters.Then the sound speed characteristics are extracted,such as the sound speed thermocline and the sound channel axis.Analyze seasonal variable characteristics of surface sound speed,sound speed thermocline and sound channel axis,respectively and obtain their distribution rules.The results show that surface sound speed mainly varies between 1520 m•s^(-1 ) and 1540 m•s^(-1 )and sound speed isolines are parallel to latitude lines,decreasing from low latitude to high latitude and sound speed varies greatly with seasons.The mean position of the sound speed thermocline in the low latitude area is different from that in the high latitude area,between 100 m and 650 m.The sound speed thermocline in high latitudes is more affected by seasonal variation.The depth of the sound channel axis is almost more than 800 m,which is little affected by seasonal changes.In general,the distribution of the sound channel axis is deep in the north and south and shallow in the middle.