Volume 17, No. 1, January 2017, Pages 262-277 PDF(5.36 MB)
Performance Evaluation of the WRF-Chem Model with Different Physical Parameterization Schemes during an Extremely High PM2.5 Pollution Episode in Beijing
Dongsheng Chen1,2, Xin Xie1, Ying Zhou1, Jianlei Lang1, Tingting Xu3, Nan Yang1, Yuehua Zhao1, Xiangxue Liu1
1 Key Laboratory of Beijing on Regional Air Pollution Control, Beijing University of Technology, Beijing 100124, China
2 Visiting scholar at Department of Environmental Sciences, Faculty of Science and Engineering, Macquarie University, NSW 2109, Australia
3 Department of Environmental Science, Peking University, Beijing 1000871, China
- Different physical parameterization schemes applied in WRF-Chem was explored.
- This study investigated a high PM2.5 pollution episode that occurred in January, 2013.
- For PM2.5, the YSU PBL, Goddard SW and GFDL LW schemes combination performed best.
To understand the impacts of different combinations of planetary boundary layer (PBL), short-wave (SW) and long-wave (LW) radiation schemes on the simulation results of meteorological variables and PM2.5 concentrations under extremely heavy pollution conditions, the Weather Research and Forecasting model with Chemistry (WRF-Chem) model was applied in Beijing to investigate a high PM2.5 pollution episode that occurred in January, 2013. Four PBL schemes, two SW schemes and three LW schemes with a total of 12 ensemble experiments were conducted in this study. The simulated meteorological variables including the temperature at 2 m (T2), the wind speed at 10 m (WS10) and the relative humidity (RH) were compared with their actual observations and the PM2.5 concentrations. A correlation analysis between the PM2.5 and T2, WS10 and RH values was also explored. The results indicated that there were no ideal scheme combinations that were most suitable for all meteorological variable simulations during this heavy pollution episode in Beijing. With the same emissions input, the simulation results of the WRF-Chem model that were configured with different physical parameterization schemes may vary significantly. As for the PM2.5 simulation, the combination of the YSU PBL, Goddard SW and GFDL LW schemes showed the greatest consistency with the observed values. Although the PBL schemes have the dominant impacts on the simulations of meteorological variables, the selection of LW and SW schemes is of the same importance.
Heavy haze pollution; Numerical simulation; Physical parameterization schemes.