Tidal fluctuation of the surface currents of the Kuroshio in the East China Sea

Abstract Significant fluctuations of the currents of the tidal frequencies have been detected in the Kuroshio Current northeast of Taiwan and in the Tokara Strait, with total amplitudes comparable to the mean surface current (about 40∼50 cm s −1 ). At the continental shelf the tidal signal varies considerably with distance from the axis of the Kuroshio. Tidal ellipses on the continental shelf consistently have major axes in the northwest-southeast direction. Because tidal signals in the Kuroshio regions have very small spatial scales, they may not be caused by the barotropic tide but the baroclinic tide. It is inferred that the Kuroshio interacts with the baroclinic tides over the continental slope.