Surface waves excitation by internal wave

The paper describe theoretically the experimentally observed effects of interaction on the basis of nonlinear SW(surface wave) modulation wave model. The SW generation in the IW field can be analyzed including higher-order dispersion into the surface wave description. A uniformly valid steady model of the IW(internal wave) interaction with nonlinear Stokes surface waves, including both the deep SW amplitude-frequency modulation will be considered under the conditions closed to the group resonance. Such a model can be constructed with allowance for the SW nonlinear dispersive properties that involves inevitably the impact of amplitude variations on the SW frequency in an inhomogeneous medium. An analysis of quasi resonant conditions, at which SWs are strongly modulated by the IW train, allows establishment of quantitative parameters of the interaction. The problem is studied in the adiabatic approximation neglecting energy sources and sinks, for example, caused by wind and viscosity. This allows a pure representation of the role of nonlinearity when describing some fundamentally new observed experimental effects.