Evaluations of WRF-CMAQ/CAMx Performance in East Asia Focusing on the Seoul Metropolitan Area

Abstract

Comparative study of two chemical transport models of CMAQ and CAMx with WRF (Weather Research and Forecasting) model under the identical conditions of meteorological field as well as emission inventory was carried out to evaluate their performances to predict atmospheric aerosols in East Asia focusing on the Seoul Metropolitan Area. Predicted concentrations of PM10, PMC (particulate matter with less than 10 μm and larger than 2.5 μm), PM2.5, sulfate, nitrate, organic carbon, elemental carbon and soil component were compared with those measured in Korea especially with intensive measurements in the SMA. CMAQ and CAMx generally depicted the variation of temporal trend and spatial distribution of the aerosols components but the PM10 and PMC were intrinsically underestimated by both models due to inherent uncertainty and lack of information for emission data of fugitive soil dusts. CAMx has a tendency to predict higher PM species concentrations than those of CMAQ. According to soccer plots of fractional bias vs. fractional gross error in annual PM chemical species, both CMAQ and CAMx, however, are acceptable in the range of between good performance and average performance. It is inferred from this study that the main reasons to induce differences between CMAQ and CAMx in predicting PM species are due to dry deposition mechanism and nesting method. © Springer Science+Business Media Dordrecht 2014.