Sensitivity Analysis of the Lorentz Energy Cycle 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. We focus on those aspects of the LEC related to the dissipation of mesoscale eddy energy. 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. We analyse how these parameterizations are responsible for the simulated eddy energy dissipation. Dedicated sensitivity experiments estimate uncertainties arising from these parameterizations when typical friction parameters are modified. These experiments allow to assess the impact on the overall energy balance. Furthermore, we discuss how inertial and sub-inertial motions influence the overall energy dissipation. Overall, this study aims to provide the basis for future, more realistic diagnostics and parameterizations of the processes involved in eddy dissipation.