Semidiurnal Internal Tides on the Continental Shelf off Abidjan

Abstract

Important semidiurnal internal tides with a maximum displacement of isotherms of about 30 m were observed on the continental shelf, near the submarine canyon Trou-Sans-Fond off Abidjan, Ivory Coast. It is proposed from a two-layer submarine canyon model experiment that the observed internal tides could have been generated by an interaction between the bottom topography of the submarine canyon and oscillatory longshore tidal currents and have propagated away on both sides of the canyon. The estimated wavelength and phase speed of the M2 internal tides of the region were respectively 22 km and 0.5 m s?1. The asymmetric profiles of isotherms and baroclinic currents were explained in terms of the nonlinear effects of the internal waves.