GENERATION OF INTERNAL WAVES OVER A SHELF

Experiments are performed in a 13-m cylindrical tank co study the gene ration of interfacial internal waves by barotropic sinusoidal waves pa ssing over a slope. At each tidal cycle, there are two waves generated , one propagating onshore and the other propagating offshore. The ampl itude of the waves increases with increasing forcing and evolves as no nlinear waves if the shelf width is smaller than the wavelength of the baroclinic tide. Rotation does not modify the generating mechanism bu t the amplitude of the generated waves decreases with increasing rotat ion rate; also no internal waves are generated when the forcing period is larger than the inertial period, and at high rotation rate, there are only dispersive waves propagating from the shelf break region. The experiments covered a large range of internal Froude number, Rossby n umber and temporal Rossby number and compare well with in situ observa tions. (C) 1998 Elsevier Science B.V. All rights reserved.