长江口及济州岛附近海域变性水团的初步分析

基于变性水团的概念,本文把聚类分析用于确定长江口及济州岛附近海域变性水团的边界。由聚类分析得到的结果表明,在该海区有十个水团。对它们的特征、分布与变化进行了初步分析。作者得出的结论是:1、在十个水团中,有四个大洋性水团,六个变性水团。2、该海域水团变性的特点为暧季增温、降盐、降氧,而冷季则相反。3、水团变性是由海区内、外因素综合作用而发生的,而后者在浅水区域起主要作用。4、水团边界的舌状分布与流向之间有明显关系。因之,海流的方向及强度,大致可依水团舌状分布而判断。5、底层中心渔场基本上位于各变性水团之间的混合区或其附近。

A PRELIMINARY ANALYSIS OF MODIFIED WATER MASSES IN THE SEA AREA NEAR THE YANGTZE RIVER MOUTH AND THE CHIJUDO ISLAND

Hased on the idea of modified water masses, a cluster analysis is used for determining the boundary of modified water masses in the sea area near the Yangtze River Mouth and Chijudo Island. The results obtained by the cluster method show that there are ten water masses in this area. A preliminary analysis of their characteristics, distributions and variances has been made.Through the analysis for them, the conclusions are as follows. First, there are four oceanic and six modified water masses in ten water masses. Secondly, the characteristics of modification of water masses in this area are the increase of temperature and the decrease of salinity and oxygen in warm season and the reversal of them in cold season. Thirdly, the causes of modification of water masses result from the combinative actions of internal and external factors in the sea and the latter plays a major part in shallowsea area. Fourthly, the correlations between the tonguelike distribution of the boundary of water masses and the current direction are apparent, there fore, the current direction and strength may largely be judged by thy tonguelike distribution of water masses. Lastly,the central fishing grounds at bottom layer largely lie in the mixed regions among modified water masses or the near area of them.