大振幅内部孤立波の伝播過程における非線形現象

Abstract

Nonlinear interaction between internal waves including very large amplitude waves has been numerically simulated using nonlinear internal-wave equations based on a variational principle. When an internal solitary wave is reflected at a vertical wall, the amplification factor of wave amplitude becomes lager as the ratio of the amplitude of incident wave to the limit amplitude of internal solitary wave is moderate, where the kinetic energy is predominant in the wave energy. As the amplitude of internal wave is close to the limit amplitude of internal solitary wave, the internal wave shows linear characteristics, such that the kinetic energy nearly equals to the available potential energy. Internal waves of very large amplitude propagating over an upslope or a downslope have also been examined, where the energy of the main wave is almost conserved.