Low resolution rotating radiative-convective equilibria in large domains

Rotating radiative-convective equilibrium, using the column physics and resolution of GCMs, is proposed as a useful framework for studying the tropical storm-like vortices produced by global models. We illustrate these equilibria using the column physics and dynamics of the GFDL AM2.0 model at resolutions of approximately 200, 100, and 50 km, in a large 20,000 x 20,000 km horizontally homogeneous domain with fixed sea surface temperature and uniform Coriolis parameter. The large domain allows a number of tropical storms to exist simultaneously. Once equilibrium is attained, storms often persist for hundreds of days and rarely merge. The number of storms decreases as sea surface temperatures increase, while the average intensity increases. As the background rotation is decreased, the number of storms also decreases. We discuss possible theories for storm number as a function of model parameters. These computations suggest hypotheses to be addressed in the future with cloud-resolving simulations of rotating radiative-convective equilibria.