Performance Evaluation of Ultra-High-Resolution Climate Simulations

Currently production climate simulations typically occur at rather coarse resolution, withO(100 km) separation between grid points. This choice of resolution is a direct result of limited computing resources. While 100 km resolution is sufficient to resolve global and large continental scale features and trends in the climate system, it is insufficient to resolve regional features. Encouraged by the recent advent of very large-scale compute platforms, we have developed a more scalable and flexible coupling infrastructure that allows for significant increases in resolution and processor counts. Our new coupler infrastructure has enabled the coupling of an atmosphere and land model with either a ∼ 25 km (0.25◦) or ∼ 50 km (0.5◦) separation between grid points to an ocean and sea ice model with ∼ 10 km (0.1◦) separation between grid points. We describe the performance and scalability of ultra-high-resolution climate simulations on as many as 6380 cores on multiple large parallel compute platforms.