【作者】 刘勇刚； 袁耀初； 山本浩文；

【Author】 Liu Yonggang,Yuan Yaochu, Yamamoto HirofumiSecond Institute of Oceanography, State Oceanic Administration,Hangzhou 310012Key Lab of Ocean Dynamic Processes and Satellite Oceanography,State Oceanic Administration,Hangzhou 310012Japan Marine Science and Technology Center, Yokosuka 237

【机构】 国家海洋局第二海洋研究所国家海洋局海洋动力过程与卫星海洋学重点实验室； 日本海洋科学技术中心；

【摘要】 基于日本“海洋”号和“长风丸”号调查船自1993年7月至1994年5月共五个航次的水文和气象调查资料,采用改进逆方法和改进的动力计算方法,计算了琉球群岛东南海域海流的流速和流量.结果表明:(1)1993年7月在石垣岛和西表岛以南断面L1上22°-23°N附近的海域,有一个弱的气旋式的冷涡;在宫古岛东南21°-24°N之间的海域则主要被一个自表层至深层的反气旋式暖涡所控制;在宫古岛东南海域断面L2上出现两个东北向流核心,其中北侧的一个核心(至少表层这支东北向流,即台湾以东海域黑潮的一个分支),通过上述冷涡和反气旋式暖涡之间海域,成为琉球海流的来源之一;南侧的一个核心成为反气旋式涡旋的一部分.(2)这支表层东北向流的流量约为6×106 m3/s.通过宫古岛东南海域断面L2的东北向和西南向流量分别为32.8×106和37.7×106m3/s.(3)在冲绳岛及奄美大岛东南海域,1993年8月、1994年3和5月三个航次都有东北向的琉球海流,并位于近冲绳岛一侧的陆坡上.琉球海流最大流速在20-23 cm/s之间,流核均位于次表层.琉球海流以东有西南向海流.琉球海流以西也常有西南向逆流出现.1994年3月航次,在奄美大岛东南海域有一支东北向海流,其强度比在冲绳岛东南海域的东北向海流更强,它们的东北向流量分别为20.8×106和7.2×106 m3/s.(4)上述计算结果与ADCP测流相比吻合较好.更多还原

【Abstract】 Based on the hydrographic data obtained from R/Vs Kaiyo and Chofu Maru during five cruises from the summer of 1993 to the early summer of 1994, the current velocities and volume transports southeast of the Ryukyu-gunto are calculated by the modified inverse method and the modified dynamic method. The computed results show that: (1) in the summer of 1993, a weak cold eddy appears at 22°-23° N in the northern part of Section L1 south of Iriomote-jima and Ishigaki - jima, and a stronger warm eddy is located at about 21°-24° N at Section L2 southeast of Miyako-jima. Southeast of Miyako-jima, there are two northeastward current cores at Section L2.The northern core, the northeastward current at least in the surface layer, i. e. , one of the Kuroshio branches east of Taiwan Island, flows between the cold and the warm eddies, and becomes one of the origins of the Ryukyu Current. The southern core becomes one part of the warm eddy; (2) the volume transport of this northeastward surface current is about 6×106m3/s. The northern and southern volume transports through Section L2 are 32.8×106 and 37.7×106m3/s, respectively;(3)in August 1993, March and May 1994, there are northeastward currents over the slope east of the Ryukyu-gunto. The maximum veloc-ities of the Ryukyu Current in the three cruises vary between 20 and 23 cm/s, with the current cores lying in the subsurface layer. A southwestward current exists east of the Ryukyu Current, and a southwestward countercurrent also often exists west of the Ryukyu Current. In the cruise of March 1994, the northeastward current southeast of Amami-Oshima is stronger than that southeast of Oki nawa-jima, and their northeastward volume transports are 20.8×106 and 7.2×106m3/s, respectively;(4) the calculated velocities are in good agreement with those measured with ADCP.更多还原