A GPU‐Based Ocean Dynamical Core for Routine Mesoscale‐Resolving Climate Simulations

Abstract

We describe an ocean hydrostatic dynamical core implemented in Oceananigans optimized forGraphical Processing Unit (GPU) architectures. On 64 A100 GPUs, equivalent to 16 computational nodes incurrent state‐of‐the‐art supercomputers, our dynamical core can simulate a decade of near‐global oceandynamics per wall‐clock day at an 8‐km horizontal resolution; a resolution adequate to resolve the ocean'smesoscale eddy field. Such efficiency, achieved with relatively modest hardware resources, suggests thatclimate simulations on GPUs can incorporate fully eddy‐resolving ocean models. This removes a major sourceof systematic bias in current IPCC coupled model projections, the parameterization of ocean eddies, andrepresents a major advance in climate modeling. We discuss the computational strategies, focusing on GPU‐specific optimization and numerical implementation details that enable such high performance.