Subtropical Mode Water south of Honshu, Japan in the spring of 1988 and 1989

The distribution and characteristics of Subtropical Mode Water (STMW) south of Honshu, the main island of Japan, were investigated using CTD, XBT, and dissolved oxygen data taken by the research vessels in the spring of 1988 and 1989. A comparatively low inventory of STMW was shown in spring 1988 during the large-meander period of the Kuroshio south of Honshu, while in spring 1989 during the non-large-meander period, the observation showed a considerable inventory of STMW which had outcropped east of 140°E in the preceding winter. These observations, together with published temperature maps, surface current charts, time series of vertical temperature profiles along 140°E, and wintertime Monsoon Index consistently support the climatology of the STMW circulation recently presented by the authors. That is, the change of the Kuroshio Countercurrent associated with the large meander of the Kuroshio most likely cuts off the westward/southwestward advection of STMW from its formation area east of 140°E.