Energy fluxes in the oceanic internal wavefield

Giovanni Dematteis

The rate of diapycnal mixing, largely due to internal-wave breaking, is a key ingredient to understanding upwelling and horizontal circulation in the ocean. Here, we show a first-principles quantification of the downscale energy flux in the internal wavefield, that ultimately feeds the wave-breaking, shear-instability energy sink responsible for mixing. The approach is based on the wave kinetic equation that describes the modal energy transfers via 3-wave nonlinear resonant interactions. Our results compare favorably with the phenomenological ‘Finescale Parameterization’ formula, by which oceanic mixing is commonly described.

Related paper: https://arxiv.org/abs/2010.06717, https://arxiv.org/abs/2106.02572