2011: Assessing possible dynamical effects of condensate in high resolution climate simulations

In areas of heavy precipitation, condensed water species can add signif-3 icant mass to an atmospheric column. This mass can create positive pres-4 sure anomalies of up to several hPa at the surface. This pressure is expected5 to force a divergent component in the low-level flow that may have an im-6 pact on the evolution of the precipitating system. In this study we examine7 results from a cloud resolving model simulation of tropical convection to es-8 timate the pressure induced by condensates. A simple parameterization of9 this condensate loading as a function of surface rain rate is derived and im-10 plemented in the National Center for Atmospheric Research’s Community11 Atmosphere Model version 5 (CAM5). Our results suggest that at horizon-12 tal resolutions of 25 km condensate loading is an important factor in con-13 trolling the frequency of intense rain rates in the model.1