An Analytical Model Connecting Tropical MCS Convective Cores to Stratiform Region Growth Rates

Tropical mesoscale convective system (MCS) cloud shields have significant impacts on atmospheric radiation and water budgets. In this presentation, we discuss work on improving our understanding of these cloud shields at the system scale via development of a simple analytical source – sink model for MCS cloud shield areas (whose terms were informed by multiple satellite and ground-based data products and WRF simulations). The source – sink model was applied to tropics-wide systems (~40,000 systems in total for March – Dec 2014), and it was found that despite its simplicity, the analytical model works equally well for systems over land and ocean and for systems characterized by varying degrees of aggregation and longevity. In this presentation, we will discuss the following: how the analytical model source term for stratiform region varies as a function of mesoscale aggregation of convective cores (despite not taking such aggregation into account during model development); use of the model in understanding variations of MCS stratiform anvils in LES experiments; and, plans for use of the model in parameterization of stratiform area in the NASA GISS Earth System Model (ModelE).