Years-long Global Storm Resolving Model Simulations in GFDL X-SHiELD

We present years-long simulations from the GFDL eXperimental System for High-resolution prediction on Earth-to-Local Domains, X-SHiELD. Unprecedented years-long integrations at 3.25-km global resolution, in present day and in perturbed climates (4xCO₂, +4K SST) is made possible by X-SHiELD’s efficiency, robustness, and accuracy. These simulations allow explicit convection to be studied as a global phenomenon and to give information about heavy precipitation and severe weather. We describe the fidelity of the mean climate and variability in these simulations; and changes to intense convection, mountain snowpack, clouds, and radiation. We also discuss further use cases for X-SHiELD, ties to weather and subseasonal applications in other SHiELD configurations, and prospects for further development.

Figure: Tracks of 2--5 km Updraft Helicity (UH; green positive, magenta negative) over the Western Pacific during a four-day period in a year-long X-SHiELD simulation. Note that positive (counter-clockwise) UH predominates in the subtropical latitudes while closer to the equator there are roughly equal numbers of both senses of UH rotation. From Harris et al., 2023, JGR-Atmospheres.