黑潮水入侵南海的水文分析──Ⅱ.1994年8—9月期间的观测结果

HYDROGRAPHIC ANALYSIS ON THE INTRUSION OF THE KUROSHIO INTO THE SOUTH CHINA SEA Ⅱ.OBSERVATIONAL RESULTS DURING THE CRUISE FROM AUGUST TO SEPTEMBER IN 1994

利用1994年8－9月期间，由台湾海峡两岸的4艘海洋调查船在南海东北部海域所获之CTD和ADCP资料，并结合1992年3月间在同一海域获取的CTD资料及部分历史水文资料，对该区域的海水特性以及黑潮水入侵南海等问题进行了分析探讨。结果表明：调查期间，本海区水团分布与冬末、春初（1992年3月）航次基本相似，即南海和西北太平洋海域的海水结构有着各自相对独立的温、盐度特性。虽发现有黑潮水穿越巴上海峡进入南海，但其势力甚弱。因此，在夏末秋初，黑潮亦无直接的分支深入南海，即使在巴士海峡北端进入台湾海峡的黑潮水，其影响也是十分微弱的。由等密度面、地转流分析和实测ADCP资料显示，在调查海区的东南海域存在一支较强的N向流动。它沿菲律宾西海岸北上，绕过吕宋岛西北角流向东北，在巴上海峡呈现与黑潮水混合的迹象，其水体在冬季明显呈高温、低盐的特性；夏季则为相对低温、低盐。故在冬季的几幅卫星图像上也有较好的体现，很有可能长年存在。

The water properties and the intrusion of the Kuroshio water into the South China Sea wer further analyzed and discussed based on the CTD and ADCP data in the northeastem South China Sea during Angust and September 1994, and combined with some historical hydrographic and sateilite remote sensing data, as well as CTD data of nearly the same area in March 1992- The results showed that the distribution of water masses in the study area was basically similar with that of the last cruise in Mareh 1992, that is, there wer the reative independent characteristics of temperature and salinity for the structure of the water bodies between the South China Sea and the Northwestern Pacific Ocean. Though the Kuroshio Water was found to enter into the South China Sea passed through the Bashi Channel, its influence was weak. Thus, there was no direct branch of the Kuroshio current deep into the South China Sea. Even though a few water bodies of Kuroshio entered into the sea area of Taiwan Shait from the northem tip of Bashi Channel, the effect of the Kuroshio was still weak on the northeastern South China Sea and Taiwan Strait.Based on analyses of isopycnic surface and geostrophic flow, as well as ADCP data,it was shown that there was a stronger northward flow in the southeast of survey area,Which flowed north along the west coast of the Philipines and rounded the northwest corner of Luzon Island, and finally turned to the northeast. In the Bashi Channel, it mixed with the Kuroshio water, and was characterized by high temperature and lowe salinity in winter and reatively low temperature and lower salinity in summer So that, this water body can be found on several satellite images in winter, and ndght exist throughout the year.