Interaction of a Cumulus Cloud Ensemble with the Large-Scale Environment. Part IV: The Discrete Model

Abstract An application of the Arakawa-Schubert (1974) cumulus parameterization to a prognostic model of the large-scale atmospheric circulations is presented. The cloud subensemble thermodynamical properties are determined from the conservation of mass, moist static energy and total water (vapor, suspended liquid water and precipitation). Algorithms for calculating the large-scale forcing and the mass flux kernel are presented. Several methods for solving the discrete version of the integral equation for the cumulus mass flux are discussed. Equations describing the cumulus feedback on the large-scale thermodynamical fields are presented.