6.3 Sensitivity of numerical simulations of a convective system and associated cold pools to WRF physics parameterizations

Lin, Chao, and Zhaoxia Pu, University of Utah

The convective cold pools are caused by the convection systems. At the same time, they have impacts on both the development and initiation of the convective systems. In this study, a major convective case during the Midlatitude Continental Convective Clouds Experiment (MC3E) in April –June 2011 is simulated using mesoscale community Weather Research and Forecasting model (WRF) at high resolution, with triple nested domains at 12km /4km/1.33km grid resolution. Radar observations and surface Mesonet data are used to evaluate the simulation results. It is found that the WRF model is able to produce the reasonable simulation of the convective case. However, the simulations of the convective initiation and cold pools are sensitive to the choice of physics parameterization options in cloud microphysics, surface layer physics and planetary boundary layer (PBL). Specifically, various physical parameterizations result in different time, location and intensity of the convective initiation and evolution, while all experiments did not well assimilate the surface cold pools. Detailed diagnistic results will be presented.