Velocity Profile of the Kuroshio Measured with Shipborne ADCP.

Abstract

Velocity structure of the Kuroshio in East China Sea and south off Japan is investigated by analysing ADCP data for the period from 1985 to 1990. By analysing the ADCP data obtained along two meridional regular observation lines, it is shown that the horizontal structure of the Kuroshio south off Japan has big difference by the location of the Kuroshio axis ; in the cases when it flows closer to the coast and when it does far south from the coast. In the former cases, horizontal structure of the eastward velocity decreases rapidly with its distance from the Kuroshio axis onshoreward, and slowly offshoreward, that shows an asymmetric profile. In the latter, on the other hand, it shows rather symmetric. By calculating gridded mean velocities, vertical profile of the Kuroshio current is proposed that the vertical shear down to 200 m is almost linear in the region south off Japan, and the speed at 200 m there is approximately half of the surface current.