The circulation on the both sides of the Ryukyu Islands during the summer of 1995 and 1996

Based on the CTD data obtained by the R/V Chofu Maru in summer cruise of 1995 and the R/V Yoko-Maru in summer cruise of 1996,respectively,the currents on the both sides of the Ryukyu Islands are calculated by the P-vector inverse method.The calculated results for two summer cruises of 1995 and 1996 show that:(1) A maximum velocity of the Kuroshio is about 115 cm/s in the summer of 1996,which is greater than that in the summer of 1995.The Kuroshio in the summer of 1996 is stronger than that in the summer of 1995.(2) In the summer of 1995 there is a northeastward current(the Ryukyu Current) east of the Ryukyu Islands.A weaker southwest-ward countercurrent exists under the Ryukyu Current.There is a meso-scale anticyclonic eddy east of the Ryukyu Current,which is a warm water from the surface to the lower layer.This warm eddy is located at 25°～25°30'N,128°30'～129°10'E,and its average speed is about 15 cm/s.(3) In the summer of 1996 a south ward current appears in the surface layer east of the Ryukyu Islands while the Ryukyu Current doesn't appear obviously.The Ryukyu Current exists in the layer below of 200 m level.Its corelies in the subsurface layer,and its maximum velocity is about 14 cm/s at 300 m level.A south ward current also exists under the Ryukyu Current.There is also an anticyclonic warmeddy east of the Ryukyu Current.Its position moves northward in the summer of 1996 than that in the summer of 1996.In the region southeast of the Okinawa Island there are an anticyclonic warm and a cyclonic cold eddies,respectively.These two eddies compose adipole,which is discovered first in this region.There is a southward current between the above two eddies with the maximum velocity of 36 cm/s at the surface.