On a spectrum of nonlinear internal waves in the oceanic coastal zone

Abstract. This paper studies the internal wave band of temperature fluctuation spectra in the coastal zone of Pacific ocean. It is observed that on the central Mexican Pacific Shelf in the high-frequency band of temperature spectra the spectral exponent tends to ~ω^-1 at the time of spring tide and ω^-2 at the time of neap tide. On the western shelf of the Japan/East Sea, in the Ω<<ω<< N_* range, where N_* is the representative buoyancy frequency and Ω is the inertial frequency, the rate tends to ~ω^-3. These features of spectra are simulated by the model spectrum of nonlinear internal waves in the shallow water. Interaction of high-frequency internal waves with an internal wave of semidiurnal frequency is considered. It is shown that as a result of the interaction the spectrum of high-frequency internal waves take the universal form and the spectral exponent tends to ~ω^-1.