Sack Lunch Seminar – Giovanni Dematteis (RPI)

Internal wave turbulence and finescale parameterizations of ocean mixing

Abstract:
The rate of diapycnal mixing, largely due to internal-wave breaking, is a key ingredient to understanding upwelling and horizontal circulation in the deep ocean. We show a first-principles quantification of the downscale energy flux in the internal wavefield, which ultimately feeds the wave-breaking, shear-instability energy sink responsible for mixing and dissipation. The approach is based on the wave kinetic equation that describes the inter-scale energy transfers via 3-wave nonlinear resonant interactions. Our results compare favorably with the phenomenological “finescale parameterization” formula, by which oceanic mixing is commonly implemented in the global circulation models, indicating a way forward for a new generation of process-driven parameterizations.

About this Series: The Atmosphere, Ocean and Climate Sack Lunch Seminar Series is an informal seminar series within PAOC that focuses on more specialized topics than the PAOC Colloquium. Seminar topics include all research concerning the science of atmosphere, ocean and climate. The seminars usually take place on Wednesdays from 12-1pm. The presentations are either given by an invited speaker or by a member of PAOC and can focus on new research or discussion of a paper of particular interest. Contact: sacklunch-committee@mit.edu