The University of Washington Shallow Convection and Moist Turbulence Schemes and Their Impact on Climate Simulations with the Community Atmosphere Model

Abstract This paper describes a new version of the University of Washington shallow cumulus parameterization. The new version includes improved treatments of lateral mixing rates into cumulus updrafts, the evaporation of precipitation and of the interaction of cumuli with the underlying subcloud layer, and a treatment of the convective inhibition-based mass-flux closure that is more numerically stable and is suitable for the long time steps of global climate models. The paper also documents its performance when combined with a new moist turbulence parameterization in simulations with version 3.5 of the Community Atmosphere Model (CAM3.5). A single-column simulation of nonprecipitating trade cumulus shows…

• UO
  University of Washington