CAJ | 학술논문

次表层高盐水(>34.68‰)作为北太平洋热带水(NPTW)的示踪,可用来研究黑潮入侵,了解南海与太平洋的水体交换。文章利用基于高分辨率混合坐标海洋模式(HYCOM)的海洋再分析资料,研究了南海北部次表层高盐水的季节变化及其影响因子。模拟结果显示,南海北部高盐水位于100~200m水深,最西可达111°E,其体积存在明显的季节变化,12月达到极大值,6月达到极小值。进一步的分析表明,其季节变化主要受低纬度西北太平洋大尺度环流的调制,与北赤道流分叉点位置的季节变化(1月到达最北端、6月到达最南端)呈现很好的相关性。受太平洋大尺度风场的影响,北赤道流分叉点上半年(下半年)向南(北)移动,导致黑潮输运增强(减弱),通过吕宋海峡进入南海的盐通量减少(增加),从而使南海次表层高盐水的盐度降低(升高)。吕宋海峡断面的流速和盐通量分布特征显示,西太平洋高盐水主要通过吕宋海峡中部(20°~21°18￠N）进入南海北部。
차표층고염수(>34.68‰)작위북태평양열대수(NPTW)적시종,가용래연구흑조입침,료해남해여태평양적수체교환。문장이용기우고분변솔혼합좌표해양모식(HYCOM)적해양재분석자료,연구료남해북부차표층고염수적계절변화급기영향인자。모의결과현시,남해북부고염수위우100~200m수심,최서가체111°E,기체적존재명현적계절변화,12월체도겁대치,6월체도겁소치。진일보적분석표명,기계절변화주요수저위도서북태평양대척도배류적조제,여북적도류분차점위치적계절변화(1월도체최북단、6월도체최남단)정현흔호적상관성。수태평양대척도풍장적영향,북적도류분차점상반년(하반년)향남(북)이동,도치흑조수운증강(감약),통과려송해협진입남해적염통량감소(증가),종이사남해차표층고염수적염도강저(승고)。려송해협단면적류속화염통량분포특정현시,서태평양고염수주요통과려송해협중부(20°~21°18￠N）진입남해북부。
Subsurface high salinity (>34.68‰) is often used as an indicator of the North Pacific Tropical Water (NPTW). It is also used as an indicator of the Kuroshio intrusion into the South China Sea (SCS). It is used here to investigate water exchange between the SCS and the northwestern Pacific. Using high-resolution hybrid coordinate ocean model (HYCOM) global assimilation data, we investigate seasonal variation of subsurface high salinity water in the northern SCS and the influence from the northwestern Pacific. Results show that there exists obviously seasonal variation in the subsurface high salinity water at about 100~200 m depth, reaching as far west as 111°E in the northern SCS, and the salinity reaches its maximum (minimum) in December (June). Further analysis shows that the seasonal change of high salinity water is strongly affected by the seasonal variation of large-scale circulation in the low latitude northwestern Pacific. The volume changes of the high salinity water is highly correlated with the bifurcation latitude of the North Equatorial Current (NEC), which reaches <br> northernmost latitude in January and southernmost latitude in June. Due to the large-scale wind change in the Pacific, the Kuroshio transport strengthens (weakens) when the bifurcation latitude of the NEC shifts to the south (north) during the first (second) half year, the salinity flux diminishes (increases) from upper northwestern Pacific into the SCS through the Luzon Strait, and the intrusion of the subsurface high salinity water in the northern SCS weakens (enhances). The velocity and salinity flux distribution in the Luzon Strait show that the high salinity water mainly enters the northern SCS between 20°~21°18￠N.