A Preliminary Simulation Study of an East Asian Super Dust Storm by Unstructured Mesh Air Quality Model

Based on the Nested Air Quality Prediction Model System (NAQPMS) developed by the Institute of Atmospheric Physics, Chinese Academy of Sciences (IAP/CAS) and the finite element fluid model (Fluidity) designed by the Applied Modeling and Computation Group, Imperial College of London (AMCG/ICL), an unstructured mesh dust transport model (Fluidity-Dust) has been constructed and employed to simulate and reproduce the outbreak of the Asian super dust storm during 19-22 March 2010 and the evolution of the three-dimensional dynamic process involved in this super dust storm. Results of this study provided new intuitive knowledge and understanding of the dust storm event. The FY-2D satellite dust images and the MODIS (Moderate Resolution Imaging Spectroradiometer) observations of AOD (Aerosol Optical Depth) were used to compare with the simulation results on the whole. To investigate the spatial and temporal distributions of PM10 at different areas, the modeled results were compared with surface PM10 observations at nine Chinese cites, while Japanese lidar measurements were used to evaluate the vertical dust profiles when the dust storm passed by the monitoring sites. Model results have also been compared with the corresponding results of NAQPMS. The comparative analysis showed that the model performed well and could realistically reproduce the evolution of the dust storm. This study laid a foundation for further application of the adaptive mesh technology in real-time tracking simulation of sandstorms in the future. The comparison of different models is an important method to quantify uncertainties in the simulations. Comparative analysis of dust-transport models indicated that the uncertainty in dust flux simulation is the largest source of uncertainty in the numerical simulation of dust storms. We applied these two models that use the same dust deflation module to simulate the same dust event. Results show that different advection schemes and different calculation of deposition have significant impacts on the simulation of the dust storm.