TRR 181 Seminar "Coarse-Graining as a technique to learn about sub-grid scale fluxes – applied to kinetic and internal energy fluxes."

The TRR 181 seminar is held by Bastian Sommerfeld (Leibniz Institute for Atmospheric Physics, PhD in M4) on June 13, 11 am at Universität Hamburg, Grindelberg 5, room 008.

Abstract

In climate simulation applications, parameterizations are omnipresent and a necessity to numerically simulate climate, wheater and ocean dynamics. The go-to approach is to use diffusive parameterizations to account for various sub-grid scale effects. Many advanced parametrization techniques like the Dynamical Smagorinsky Diffusion or backscatter approaches build on the core assumption of non-local non-organized sub-grid scale fluxes. This study aims to verify this core assumption using a coarse-graining technique to make commonly diffusively parametrized processes such as the turbulent shear production term visible. Early results indicate very organized and localized structures of turbulent shear production and hence the diffusive assumption may potentially be flawed. This may be of large consequence to our understanding of entropy production in climate models and to the entirety of dynamics modeling.