Dynamics of Internal Tides Over a Shallow Ridge Investigated With a High-Resolution Downscaling Regional Ocean Model

Abstract

This study investigates the dynamics of tidally induced internal waves over a shallow ridge, the Izu-Ogasawara Ridge off the Japanese mainland, using a downscaled high-resolution regional ocean numerical model. Both the Kuroshio and tides contribute to the field of currents in the study area. The model results show strong internal tidal energy fluxes over the ridge, exceeding 3.5 kW m−1, which are higher than the fluxes along the Japanese mainland. The flux in the upstream side of the Kuroshio is enhanced by an interaction of internal waves and currents. The tidal forcing induces 92% of the total internal wave energy flux, exhibiting the considerable dominance of tides in internal waves. The tidal forcing enhances the kinetic energy, particularly in the northern area of the ridge where the Kuroshio Current is not a direct influence. The tidal forcing contributes to roughly 30% of the total kinetic energy in the study area.