Internal wave observations off Punta Tuna, Puerto Rico

Internal waves in the northeastern Caribbean Sea off the south coast of Puerto Rico have been observed in a series of 381 vertical temperature profiles to a depth of 275 m. Internal waves with periods varying from one hour to the inertial period of the Caribbean Sea were observed. The surface tides in this region are of very small amplitude, less than 0.20 m. The observed internal tides in the upper 100 m are distinctly semi-diurnal in nature with a maximum amplitude of 30 m. At depths greater than 100 m the tides become more diurnal in nature with comparable amplitudes. These internal tides produce anomalies in the sea surface elevation comparable in magnitude to the dynamic height ranges reported for the region in atlases. The origin of the internal tides is somewhat problematical. These internal tides represent a significant sink for astronomical tidal energy