吐噶喇海峡黑潮流速结构和流量的研究

STUDY ON VELOCITY STRUCTURE AND VOLUME TRANSPORT OF THE KUROSHIO IN THE TOKARA STRAIT

利用1977－1991年日本“KuroshioExploitationandUtilizationResearch”（KER）资料和日本气象厅海洋观测资料计算吐噶喇海峡的黑潮流速和流量。结果表明，海峡处黑潮主轴的平均核心流速为92．0cm／s，平均流量为周．1×106m3/s；揭示了吐噶喇海峡黑潮流速的多核结构和多股流动的突出特征。探讨了海峡中流量分布状况和季节变化。

The current velocity and volume transport of the Kuroshio in the Tokara strait were calculated by using the data of KER and observations conducted by tlie Japan Meteological Agency during 1977-1991. The main results are as follows.1. The velocity of the Kuroshio core was always varied between 41.5 and 146.2 cm/s (mean of 92.0 cm/s). The Kuroshio main stream located mainly in the area 30 n mile south of Yaku-shima. However, it moved northward usually when the core speed increased but moved southward when it decreased.2. The most predominant features of the Kuroshio in the Tokara Strait that there are several cores, branches and counter-currents of the flow. The southernmost area of the strait (between 10-12 stations) was almost totally occupied by the counter-current.3. The long-term mean volume transport of the Kuroshio in the Tokara Strait was about 24.1× 106 m3/s, but fluctuation between 11-38 ×106 m3/s. Most of the volume transport passed through the southern passege (between 6-10 stations).4. Volume transport of the Kuroshio in the Tokara Strait was much large in summer and spring, smallest in winter. The positive anomaly of mean annual transport corresponded to the maturity phase of the large meander of the Kurosliio south of Japan.