苏澳一与那国岛断面上黑潮流速结构的特征及其季节变化

自北赤道流延伸而来的黑潮，起源于我国台湾省的东南海域。当黑潮沿着台湾岛东岸北上时，它的主轴通过苏澳-与那国岛断面，自北太平洋进入我国东海，成为我国东、黄海海流系统的“大动脉”。显然，黑潮的流速结构及其变化，对东、黄海水文特征的分布、变化以及我国东部沿海地区的气候，特别是旱涝现象，都有着密切的关系。所以，有关这一问题的探讨是很有意义的。而欲研究黑潮的上述问题，取苏澳-与那国岛断面作为探讨的核心是很合适的，因为这个断面不仅离黑潮源地较近，而且位于黑潮进入东海首当其冲的关键性区域。关于黑潮在这一断面上海洋水文状态的变化情况，日本学者须田晥次(K.Suda,1937-1938)曾作过广泛的研究，他主要分析了黑潮源地区域标量场(温、盐、密度等)的逐月变化特征。本文拟引用须田当年所列举的温、盐度资料，来研究黑潮的流速结构(主要是流速分布和输送量)及其季节变化，并结合现有的海面风应力资料，试图对黑潮输送量的季节变化及其原因作一初步的探讨，并作为进一步研究黑潮变动规律的参考。

THE CHARACTERISTICS OF THE VELOCITY STRUCTURE OF THE KUROSHIO AND ITS SEASONAL VARIATION .ON THE SECTION SU'AO-YONAGUNIJIMA

This section is situated near the origin of the Kuroshio, and is the entrance for the Kuroshio frowing from the Pacific Ocean into the East China sea. Therefore, it is a key-place for monitoring the variation of the Kuroshio. In this paper, the monthly averaged hydrographical data published by Suda (1937- 1938) are used to study the velocity structure (i.e., the distribution of the velocity and the transport) and the seasonal variations of the Kuroshio. The results show that the seasonal variation of the transport has a semi-annual dominant period, and a sufficiently significant correlative relation(r= 95%) exists between the transport values of the Kuroshio in four seasons and the corresponding values of the wind-stress curl at the same latitude as the section over the middle of the North Pacific, that is, at the neighbourhood of the Hawaiian Islands.This empirical relation may be useful for the study of the tendency prediction of the Kuroshio.