Generalized Transport Characterizations for Short Oceanic Internal Waves in a Sea of Long Waves

Abstract

Internal waves in the ocean interact in triads. Early work emphasized the importance of extreme-scale separated interactions in which two large wavenumber waves interact with one small wavenumber wave. More recent efforts have called this early paradigm into question. We use wave turbulence kinetic equation and the ray-tracing WKB technique to derive two versions of the corresponding Fokker-Planck (generalized diffusion) equation. We then use these Fokker-Planck equations to estimate the spectral energy flux towards dissipation (high wave numbers) we obtain different results: spectral transport of the kinetic equation Fokker-Planck equation is an order of magnitude larger than either observations or reported ray tracing estimates. This apparent contradiction stems from the difference between Eulerian and ray-path descriptions of these scale-separated interactions.