A unified parameterization of turbulence and clouds

 

Author

Vincent Larson — University of Wisconsin, Milwaukee

Category

General Topics – Cloud

Description

Creating and publishing climate projections is fruitless unless the underlying climate models are trustworthy. Trust in a climate model is enhanced by internal consistency of model assumptions. Consistency, in turn, is aided by unifying cloud parameterizations. To this end, we have constructed a climate model, named CAM-CLUBB-SILHS, that unifies the description of turbulence and all cloud types, including stratocumulus, shallow cumulus, and deep cumulus clouds. In this model, CLUBB predicts an evolving subgrid distribution of turbulence and cloud-related properties. SILHS draws samples from this distribution and feeds them into a microphysics parameterization. The model is unified in the sense that all turbulence and cloud calculations see the same multivariate subgrid probability density function. The model also unifies the description of microphysics because it uses a single microphysics parameterization for all microphysical calculations. Global simulations using CAM-CLUBB-SILHS will be presented.