DIRECT NUMERICAL-SIMULATION OF THE ROLL-OFF RANGE OF INTERNAL WAVE SHEAR SPECTRA IN THE OCEAN

Oceanic internal gravity waves play an important role in the dynamics of the ocean, providing a link in the overall energy cascade from larg e forcing scales to small dissipation scales. Quantifying the cascade of energy available for mixing processes in the ocean interior, for ex ample, is essential to accurate modeling of the oceanic general circul ation. In the present study, based on an extensive numerical model tha t resolves most of the internal wave spectrum, the dynamics of the pro cess by which internal waves dissipate their energy in the deep ocean are investigated. Putting all the calculated results together, we prop ose here a model for the dynamic balance of the internal wave spectrum wherein a downscale energy flux into the high vertical wavenumber nea r-inertial portion of the spectrum is balanced by energy dissipation a t critical layers formed by high vertical wavenumber near-inertial flo ws.