Variations of current path, velocity, and volume transport of the Kuroshio in relation with the large meander

The variations of the Kuroshio Current path and their relations with current velocity, volume transport, and upstream position of the Kuroshio are examined using sea level data. After the long-time, non-large-meander (NLM) path during 1963-75, the Kuroshio takes a larger-meander (LM) path during most of 1975-91: 1975-80, 1981-84, 1986-88, and 1989-91. The study of these meanders confirms the description of the path of the Kuroshio based on the three typical paths and the transitions between them, with an exception being the 1981-84 LM path. The formation and decay of the large meander are associated with velocity and position of the Kuroshio in the Tokara Strait south of Kyushu. Volume transport of the Kuroshio shows an interdecadal variation, small before 1975 and large afterward; that is, the transport during the 1975-91 LM-dominant period is larger on average than that during the 1963-75 NLM path. All the LM paths are formed when the transport increases from about 24 Sv (Sv = 10 super(6) m super(3) s super(-1)), while the Kuroshio takes an NLM path whenever the transport is less than 23.5 Sv. In conclusion, LM paths occur when the Kuroshio has large or medium transport and velocity, and is in a northern position in the Tokara Strait. The northern position implies a small curvature and a large vertical inclination of current axis south of Kyushu, which may be related with the dynamics of a large meander.