摘要
本文根据日本“Komahashi”号调查船1940年2—3月的深海观测资料,从温度和动力高度的分布探讨了台湾以东黑潮深层流的途径。结果表明,在兰屿以东附近区域存在着一个尺度约为100×200km的气旋式(冷)涡旋。沿台湾东南北上的黑潮途径,约从200 m层起,随着深度的增加,绕冷涡作气旋式弯曲,主流不再径直北上,而逐渐转向东—东南。这主要是由于深层水北流时受到台湾东北方海脊的阻塞作用所致。这次台湾以东黑潮所出现的弯曲和冷涡,虽其尺度较小,强度亦弱,但其时间落在日本以南黑潮出现大弯曲和冷水团的期内(1934—1944),这两者是否存在着内在联系,值得研究。
Based on the deep sea(to 1200 m)observation data from Japanese R/V Komahashi(Feb.26-Mar.2,1940),the Kuroshio path,especially in deep layer,is investigated as a case study from temperature distribution and dynamic height topography.Main results are as follows.1.500-600 m being as a boundary,the temperature distributions in the upper and deep layers are quite different from each other.The temperature in upper layer increased,and that in deep layer decreased with the increasing of distance from the shore.A cold water area appeared to the east of Lanyu Island,its northward extension became wider with the increasing of the depth.2.Dynamic height topographies(referred to 1200 db)at each level show that a cyclonic eddy appeared in the region east of Lanyu Island.The Kuroshio south of Taiwan,passing through both sides of the eddy,flowed toward the north as a whole.But in the near surface layers,it flowed mostly toward the East China Sea.While in the deep layers,the amount of water flowing northward along the west side of the eddy decreased with increasing of depth,and that flowing eastward and southeastward along the southern and eastern part of the eddy increased,which we considered that to.be the result of the blocking effect on the northward flowing of the deep water due to the existence of submarine ridge northeast of Taiwan.From about 200 m,the path of the northward flowing Kuroshio southeast of Taiwan began to meander cyclonically around the cold eddy,the deeper the depth it located,the more it meandered.The path of main current was no longer straight northward,but turned to E-SE.At 800-1000m level around 23°N,the Kuroshio was almost entirely eastward flowing.The dimension of the cyclonic eddy is about 100X200 km.3.Volume transport(referred to 1200 db)of the Kuroshio flowing from south of Taiwan to the east coast of Taiwan is around 24 sv.Volume transport of the Kuroshio flowing toward the East China Sea is around 17 sv.Therefore,as a rough estimation,about 5-6 sv(-25%)of the Kuroshio water flowed eastward to the Pacific Ocean.4.The above-mentioned meander and cold eddy of the Kuroshio east of Taiwan occurred just in time of the appearance of the large meander and cold water mass of Kuroshio south of Japan in 1934-1944.Whether there is some intrinsic relation between these two phenomena is worth studying.5.It is suggested that the deep layer water blocked by the submarine ridge and flowing eastward may flow southward.as a reeirculation.And there is another possibility that it may be related to the deep western boundary current southeast of Ryukyn Islands(Kawabe,1980).It is expected that the deep-sea expedition east of Taiwan and south of Ryukyn Islands would be systematically carried out in the near-future,a necessary and important event for exploring the Kuroshio path in deep layer.
作者
管秉贤
Guan Bingxian(Institute of Oceanology,Academia Sinica,Qingdao)
出处
《海洋与湖沼》
1985年第4期253-260,共8页
Oceanologia Et Limnologia Sinica
