Argos浮标及模型反演吕宋海峡区域流场季节变化特征

Seasonal Variation of Kuroshio at Luzon Strait Studied with Argos and Numerical Model

针对黑潮是以流套、分支还是黑潮锋的方式侵入南海的不同观点,应用Argos浮标数据探讨了吕宋海峡黑潮的季节性分布特征,并利用区域海洋模式系统(ROMS)对吕宋海峡黑潮流态进行数值模拟,进而研究吕宋海峡表层和120.75°E断面黑潮流态的季节分布特征以及断面流量变化,并与实测值、他人的计算结果进行对比.结果显示,春夏两季黑潮主要以黑潮锋的形式存在,夏季有南海水汇入黑潮主干,秋冬两季有时会以流套形式入侵南海,并部分从台湾南部折回到黑潮主干,冬季有一小部分黑潮水以分支形式直接入侵南海.本模型计算表明:在吕宋海峡120.75°E断面上,常年有东西向海流,海峡上层的净通量为负值(流向南海),下层的净通量春季为正值,其它季节均为负值,整个断面每个季节的体积输送为太平洋水净输入南海,平均净输运量为1.305×107m3/s.

In order to determine whether kuroshio flows invade the South China Sea （SCS） in the way of current loop, branch or front,Argos data was used to study the seasonal variation of kuroshio at Luzon Strait, and the regional ocean modeling system （ROMS） was applied to simulate the current pattern in Luzon Strait. Monthly averaged zonal velocity and zonal volume transports at the 120.75°E cross-section was listed and compared with the measured data and other results. The results indicate that kuroshio exists in the form of front in spring and summer, there are flows originated from the SCS afflux into the kuroshio in summer. But in fall and winter,the kuroshio flows invade the SCS in the form of a current loop,with a part of it turns back into the main current along the south of Taiwan. Especially in winter, a branch of it invades the SCS. ROMS was used to simulate the zonal velocity at the 120. 75°E cross-section of Luzon Strait. And the results indicate that flows move westwards and eastwards respectively all year. The net volume transport is negative in the upper level, which means the tendency of the net transport flows into the SCS. While in the lower level the net volume transport is also negative in almost all seasons except spring. The net transport tendency is flowing from sea water to the SCS through Luzon Strait in each season, and the mean net volume transport is 1. 305 × 10^7 m3/s.