E3SM-MMF replaces E3SM’s atmospheric convection parameterization with a 2D cloud-resolving model that runs within each grid point. This keeps the global model running at 25–100 km resolutions while the MMF convection models run at 1–3 km. The coarser resolution for the global model allows for several hundred years-long simulation campaigns to be completed in a reasonable timeframe while also significantly improving cloud resolution. Image: ECP/E3SM-MMF.