P20 Performance of the WRF-Chem-RTFDDA system in simulating dust and visibility over the Middle East

Zhang, Yongxin, Yubao Liu, Gregory Roux, Rong-Shyang Sheu, Linlin Pan, National Center for Atmospheric Research, and Dorita Rostkier-Edelstein, Israel Institute for Biological Research

The combination of WRF-Chem and RTFDDA (Real-Time Four Dimensional Data Assimilation), WRF-Chem-RTFDDA, provides an ideal modeling system for simulating and forecasting dust storms due to (a) WRF-Chem's capability of simulating the emission, transport, mixing, and chemical transformation of trace gases and aerosols simultaneously with the meteorology, and (b) RTFDDA's capability of continuously assimilating both conventional and nonconventional observations and thus providing realistic initial conditions for improved dust analyses and forecasts. In this work, the integrated WRF-Chem-RTFDDA system is applied over the Middle East and its performance in simulating dust and visibility for two dust cases is evaluated using available observations both from surface stations and satellite measurements. The possible reasons for the model biases will be explored through sensitivity experiments.