Effects of Density Front on the Generation and Propagation of Internal Tides

Abstract A numerical model is developed to study the internal tidal motion on the continental margin. The system includes irregular bottom topography and a horizontal density stratification maintained by a mean geostrophic current. Both the propagation and generation processes are examined. In the propagation process, the topographic effect alone will scatter a significant part of the incident wave energy into higher modes, resulting in a beamlike structure for the transmitted wave. For a density front over a flat bottom, energy in the transmitted waves remains largely in the original wave mode, though the wavelength, and hence wave amplitude, varies with local density stratification. When the density front is located over a sloping bottom, the topographic effect is reduced, whereas the frontal effect is not affected. Thus, scattering into higher modes becomes more restricted. In the generation process, internal tides are produced in the upper and lower parts of the slope region due to the interaction bet...