Simulation And Analysis Of Wintertime Typical Particulate Matter Pollution Episodes In Beijing

WRF-Chem numerical simulation combined with monitoring data were used to study particulate matter (PM10and PM2.5) in Beijing and the surrounding area in Dec,2006.We analyzed the future of typical pollution process and regional transport of particulate matter pollution around Beijing by scenario analysis. The results indicates that WRF-Chem can better of simulation PM10,PM2.5and meteorological field in Beijing and around area in winter, the pollutants correlation coefficient is between0.84and0.90by analyzed monitoring value and simulation value. The simulation results for meteorological fields are better on Beijing and Tianjin, while Shijiazhuang is slightly poor. Generally, the model can simulation particulate matter and meteorological fields change characteristics in Beijing and its surrounding areas in Dec2006successfully. The model reproduced the typical particulate matter pollution process on Dec23-262006. We analyzed this formation of pollution process by different angles of near-ground and500m height, and found400-800m height is the high value area for particulate matter transportation flux by simulation the vertical profiles, and analyzed the typical particulate matter pollution mechanism by combining trends of weather situation and the meteorological elements (temperature, wind speed, PBL height, water vapor pressure and relative humidity). Analyzed the particulate matter contribution rate to Beijing by the surrounding area except Beijing, Tianjin, Hebei and Shanxi, Separately, found the influence of pollution sources by surrounding area of Beijing is prominent, average PM10contribution rate of35.6%,PM2.5of34.9%. Hebei province has the greatest effect on particulate matter pollution to Beijing, followed by Shanxi and Tianjin. We found that near-ground conveying belt can easily causes local pollution and short distance pollution transports in Beijing, while500m height is the important region transportation level with longer distance and stronger flux transportation than near-ground by analyzing back forward trajectory, near-ground and500m analysis. Therefore, if source area of transportation has centralized pollution sources, it’s an important reason to cause air pollution in Beijing area.