DINO: A Diabatic Model of Pole-to-Pole Ocean Dynamics to Assess Subgrid Parameterizations across Horizontal Scales

Abstract. Climate models are limited in resolution by computational constraints. The ocean component is currently resolved at spatial scales between approximately 10 to 100 km, which is too coarse to adequately capture the mesoscale. Eddies at these scales play a major role in the global energy cycle, and therefore it is crucial that they are accurately parameterized. In this context, we propose DINO (DIabatic Neverworld Ocean), an ocean-only model configuration of intermediate complexity designed as a test protocol for eddy parameterizations across a range of horizontal scales. It allows for affordable simulations, even at very high resolution, while crucial aspects of the global ocean like the Meridional Overturning Circulation (MOC), Subtropical and Subpolar gyres, or the Antarctic Circumpolar Current (ACC) are maintained. We compare key metrics across eddy-resolving (1/16°), eddy-permitting (1/4°) and eddy parameterizing (1°) simulations to showcase the evaluation of eddy parameterizations in two ways: by testing their impact on the mean state and by directly diagnosing the missing eddy fluxes from coarse-grained high-resolution experiments.