Numerical evaluation of the spectral evolution of internal gravity waves due to wave-wave interactions

The kinetic energy spectra of oceanic internal gravity waves (IGWs) from recent field measurements and wave turbulence theory exhibit large variability, deviating from the standard Garrett-Munk (GM) spectrum. An improved understanding of energy cascade across scales by IGWs is needed for better parameterization of smallscale dissipation and ocean mixing. In this work, we conduct direct numerical simulations of the kinetic equation, which describes the spectral evolution of IGWs due to wave-triad interactions in the wave turbulence theory. Dominant mechanisms of energy cascade are identified, and energy fluxes in the wavenumber-frequency space for non-GM spectra are calculated. This will shed light on a new formulation of finescale parameterization incorporating varying spectral slopes of IGWs and a realistic ocean environment.