Dissipation of Eddy Kinetic Energy in the ICON-O Model

This study provides an analysis of the ocean Lorentz Energy Cycle (LEC) simulated with an ICON- O configuration of 5km horizontal resolution. Since most processes relevant for eddy dissipation cannot be resolved even with 5km horizontal resolution, parameterizations are required to dissipate the energy. Typical parameterizations used in ocean models are bottom friction, vertical viscous dissipation and horizontal biharmonic dissipation. 
Here, we focus on all sources, sinks and fluxes of geostrophic eddy kinetic energy. To this end, we filter geostrophic turbulent eddies from internal waves by (a) approximating geostrophic pressure by a five day time average and (b) by using quasi-geostrophic equations to diagnose the geostrophic energetics. We find that the production of QG EKE is dominated by the baroclinic pathway. Horizontal and spatial energy pressure fluxes transport the produced energy to bottom and western margins. There it is dissipated mainly by horizontal friction, followed by bottom and vertical friction. Sensitivity simulations with altered friction parameters show, that dissipation changes marginally with respect to these alterations.