A Simple Parameterization of the Large-Scale Effects of Cumulus Convection

Abstract

A parameterization of the effects of deep cumulus convection on the large-scale heat and water budget is proposed. It is based on a simple prediction of the convective mass flux, and a global treatment of the detrainment by relaxation of the large-scale values of the temperature and the moisture towards a single cloud profile. The performances of the scheme and its sensitivity to some details of the formulation are tested, both in one-dimensional semi-prognostic computations and in three-dimensional forecasts. Abstract A parameterization of the effects of deep cumulus convection on the large-scale heat and water budget is proposed. It is based on a simple prediction of the convective mass flux, and a global treatment of the detrainment by relaxation of the large-scale values of the temperature and the moisture towards a single cloud profile. The performances of the scheme and its sensitivity to some details of the formulation are tested, both in one-dimensional semi-prognostic computations and in three-dimensional forecasts.