2014 Volume 23 Issue 5 Pages 171-196
The Kuroshio Current path has been classified into three passes: typical Large Meander path (tLM), nearshore Non-Large Meander path (nNLM) and offshore Non-Large Meander path (oNLM). We investigated these paths in more detail statistically by Discriminant Analysis using Maharanobis Distance and K-mean method (Nonhierarchical Cluster Analysis). We used the sea level data along the southern coast of Japan and the Kuroshio Axis Dataset from January 1970 to December 2009. We defined the southern limit latitude of the axis of the Kuroshio between 136 and 142°E and the northern limit one between 136 and 140°E as indices of the Kuroshio path. We classified the Kuroshio paths into four paths: Large Meander West(LMW) path, Non-Large Meander North (NLMN) path, Non Large Meander South (NLMS) path and Large Meander East (LME) path. The LMW path corresponds to the tLM path, and the NLMN path corresponds to the nNLM path: however, both axis of the LME and the LMW extend beyond 32°N before approaching the Izu Islands, and both axis of the LME and the NLMS take the path to the south of Hachijyo-jima. In the period of the Kuroshio taking the path of LME, the sea levels at Hachijyo-jima and Kushimoto are low, indicating that the LME path is one of the paths hidden in the oNLM path. In this context, the oNLM path should be divided into the LME and the NLMS paths. We also discussed the transition processes among these four paths: the change of the NLNN path to the LMW path, following LMW->LME->NLMS->NLMN.
