Bottom currents on the continental slope off Shikoku

Beneath the Kuroshio south of Shikoku, there exist bottom currents, flowing in the different direction from the Kuroshio. In order to examine their horizontal and vertical characteristics, we analyzed four current data sets obtained by lowered acoustic Doppler current profilers (LADCP) in the region south of Shikoku during 2004-2006. While the surface Kuroshio in the top 700-m layer flows eastward, the bottom currents flow toward the left-hand side of the surface Kuroshio, i.e., to the inshore side. This vertical current structure is found to be maintained even when the Kuroshio moves offshore to the deep-ocean due to the propagation of the small meander of the Kuroshio.