THE KII BIFURCATION CURRENT AND INTRUSION OF THE KUROSHIO WATER INTO THE COASTAL REGION TO THE WEST OP CAPE SHIONOMISAKI
As discussed in Section 2, there is a big contrast in oceanic features between the areas to the west and to the east of Cape Shionomisaki. This phenomenon has not been intensly investigated, but such contrast is usually seen when the Kuroshio takes the straight path (Takeuchi, personal communication).
Along the southwest coast of the Kii Peninsula, the Kii Bifurcation Current is often observed. Takeuchi et al. (1998a) showed that the Kii Bifurcation Current was found about in 70% of the 258 ADCP sections taken in the period from 1988 to 1996 by the R/V Wakayama. It was also shown that the occurrence frequency is high at the time of the straight path and low at the time of the large meandering path of the Kuroshio.
An example of the horizontal structure of the Kii Bifurcation Current observed on board the R/V Seisui-maru on June 24-25, 1997 is shown in Fig.7 (velocity field) and in Fig.8 (temperature distribution at 200 m depth) (Takeuchi et al., 1998b; Uchida et al., 2000). Along the line A, the along-line component of the current changes its sign near Susami, indicating the existence of the bifurcation current. As seen in this figure, the eastward flowing portion of the Kii Bifurcation Current near Cape Shionomisaki is considered to be the coastal edge part of the strong current zone of the Kuroshio.
