A Stochastic Mixing Model for Nonprecipitating Cumulus Clouds

Abstract

Recent work suggests that nonprecipitating cumulus clouds must be considered as aggregates of many parcels always moving toward buoyancy equilibrium, but otherwise subject to a multiplicity of fates. For example, some parcels originating at low levels seem to ascend to their level of undilute neutral buoyancy before mixing with the environment, while others mix at intermediate levels. We present a model for a cumulus cloud incorporating these ideas. In spite of the apparent simplicity of the model, it compares favorably with observations.