Abstract: Intense internal waves are common phenomena on mid-latitude continental shelves when the water column is stratified. In this paper, a nonlinear nonhydrostatic two layer model is used to examine the details of the generation and evolution of these waves. This model indicates that the internal waves are generated by the interaction of the barotropic tide with the shelf break topography. The onshore flow of the tides causes an upward displacement of isopycnals. This disturbance splits into a pair of counter propagating waves. The subsequent offshore flow causes a downward displacement which acts in conjunction with advection to steepen the back face of the onshore propagating wave. Thus an internal onshore propagating shock is developed, which eventually disintegrates into a packet of solitary internal waves (SIW) through a process of nonlinear self-interaction. Meanwhile, the model results are compared with available experiment data.

Key words: nonlinear internal wave, nonhydrostatic, cnoidal wave