Gross Moist Stability Assessment during TOGA COARE: Amplification and Decay of Convection

We examine evidence for the idea that on any given day, a quantity known as the gross moist stability (GMS) is closely related to whether deep convection is amplifying or decaying. TOGA COARE field campaign data is used to develop and test this idea. Sub-critical GMS values are associated with growth, while super-critical values are associated with decay. Vertical advection (convergence), horizontal advection, radiative and evaporation can all play a role and we examine their relative importance during day-to-day variations in deep convective activity. Vertical motion profiles turn out to play a key role through their influence on vertical advection or convergence of moist static energy.