MULTIMODAL SOLITON OF INTERNAL WAVES

The analytical expressions for first and second approximations of the stationary internal wave KdV equation were found for a rather common l aw of continuous fluid stratification. The vertical profile of the Bru nt-Vaisala frequency simulating the picnocline (seasonal or main) was described using three-parametric family of curves. Analysis of the ana lytical solution was carried out. It is shown that the second order co rrection to the main first approximation unimodal solution (mode with number n) consist of the sum of modes. The modes with the numbers n 1 and n - 1 (neighboring to the main mode) have the largest amplitudes . The analytical solution describing the internal wave soliton as comp lex multimodal object is consistent with the results of nimerical calc ulation. During the evolution of the initial large amplitude soliton i n the framework of complete system of equations the energy leakage fro m the initial wave to the group of the neighboring modes takes place. It leads to the formation of the multimodal solitary wave on the final stage of evolution.