GENERATION OF NONLINEAR INTERNAL TIDES AND SOLITARY WAVES

A set of generalized Boussinesq equations is derived for internal wave s in a two-layer system; the effects of earth's rotation are included by using the f-plane approximation; a forcing mechanism due to the int eraction between a tidal flow and a small finite-amplitude topography is included as well. These equations thus enable the study of the gene ration of nonlinear internal tides and the effects of nonhydrostatic a nd Coriolis dispersion on the evolution of the internal tide. Numerica l solutions of the equations are presented. The three main appearances of the internal tide are considered: a linear periodic wave, a cnoida l-like wave, and a train of solitary wave sequences. In the latter cas e the internal tide appears in a disintegrated form. Special attention is paid to the conditions in which such a disintegration occurs, in p articular to the influence of earth's rotation (Coriolis dispersion). Critical parameters of dispersion are derived in terms of the strength of the forcing; these parameters indicate whether the internal tide a ppears as a coherent or as a disintegrated wave.