吕宋海峡及南海北部海域的水团分析

Water mass analysis in Luzon Strait and northern South China Sea

根据1992年3月和1994年9月台湾海峡两岸科学家对南海北部两次协同调查的CTD资料以及由此计算的重力势资料，对吕宋海峡及南海北部400m以上海水的温盐性质进行分析。结果发现，调查海区基本可划分为两种水团，即黑潮水和南海水。黑潮水主要从吕宋海峡中部和北部进入南海，侵入的黑潮水向西北方向扩展，受到台湾海峡海底地形的阻挡而大部分集中于台湾西南海域，向西的范围基本不超过119°E。虽然两次观测所处的季节不同（分别为春初和夏末），但黑潮入侵南海的差异并不明显。另外，在二次调查的部分层次上，南海北部陆坡边缘都发现有一团水平尺度约百公里的黑潮性质水。配合重力势的水平分布形式，可以用地转流场的结构解释水团分析的结果。

Based on two systemat1cally-arranged CTD sureys conducted by both sides of the Tai-wan Strait in March 1992 and September 1994 respectively,water mass shallower than 4oOmare analyzed in Luzon Strait and onrthern South China Sea (SCS) in order to show the spatialstructure of water properties formed by the interaction between Kuroshio and SCS throughLuzon Strait,It will help to understand the deforn1ation of Kuroshio in Luzon Strait. The re-sults show that there are two major water masses in the study area,which are Kuroshio wa-ter and SCS water. Kuroshio water is found to enter SCS through middle and northern partsof Luzon Strait and then extend northwesterly. The intrusion water concentrates in the wa-ters southwest of Taiwan due to the obstruction of bottom topography and its westward ex-panding range only arrlves at the vicinity of 119°E. Although these two surveys are in differ-ent seasons (spring and summer), there is on evident difference in Kuroshio intrusion. Onsome levels of both surveys,it has been found that there is some water of the same propertiesof Kuroshio off the continental slope of northern SCS with a diameter scale about 100km-Combined with the distribution of gravitational potential,the results may be explained bygeostrophic calculation.