OS34A-01 Calibrated OMIP simulations with Oceananigans

Abstract: We present century long global ocean and sea-ice simulations run with Oceananigans, the ocean component of the Earth System Model developed by the Climate Modeling Alliance. Oceananigans is a fast and friendly software written in the Julia language and optimized for GPUs. The simulations are run following the Ocean Model Intercomparison Project design protocol. Leveraging the computational efficiency of Oceananigans, we compare OMIP simulations run at 1, 1/4, and 1/10 of a degree to document the impact of mesoscale motions on the global ocean circulation and stratification.

We also illustrate how we use Ensemble Kalman Filters to calibrate the OMIP solutions. The calibration optimizes nondimensional parameters in the boundary layer model and air-sea fluxes to keep the solution close to available global observations. We evaluate the calibration approach by comparing the calibrated parameters with theories and large eddy simulations of the processes they are supposed to represent.