Simulation of the Influence of Aerosol Pollution on Summer Weather in Beijing-Tianjin-Hebei Region Using WRF-chem
应用WRF-chem模式模拟京津冀地区气溶胶污染对夏季气象条件的影响

Among chemistry-aerosol-cloud-radiation-climate, there are complex feedback mechanisms which exist all over the earth systems. The feedback of aerosols may include a direct feedback and an indirect feedback which influences temperature, planetary boundary layer (PBL) and wind speed, as well as precipitation on surface or near surface. With rapid economic development, China’s air pollution becomes more and more serious in the past few decades, and the regional climate has been greatly impacted. Our study aims at exploring the complex feedback between air pollution and climate change in one of the most prosperous regions of China. In this paper, the online Weather Research and Forecasting and Chemistry(WRF-chem)model was used to explore impacts of aerosols pollution on weather conditions in Beijing-Tianjin-Hebei region. The study region is situated at 34°N,109°E with a spatial resolution of 0.5°×0.5°and a dimension of 35×39 grid cells. The major physics options include the Goddard shortwave radiation scheme, the rapid radiative transfer model long-wave radiation scheme, and the Fast-j photolysis rate scheme; the chemical options include the RADM2 and MADE/SORGAM aerosols options. The modeling system was evaluated through comparing the simulation results of PM 10 , temperature of a place 2m above the ground, wind speed at a place 10m above the ground and precipatation with corresponding observations in July 2006. The month-long simulation has shown the aerosol’s direct and indirect clamatic effects on T2, PBL height and wind speed in terms of absolute differences. In Beijing, Tianjin and Shijiazhuang, the changes of T2, PBL height and wind speed are as follows: T2 values reduce by 0.17 ℃ , 0.18 ℃ and 0.23 ℃ respectively; PBL height reduces by up to 32.88m, 27.78m and 41.85m respectively; wind speed increases by 0.067m/s, 0.085m/s and 0.167m/s, respectively. Besides, as a consequence of aerosol’s indirect effects, the total precipitation in Beijing, Tianjin and Shijia-zhuang increases by 0.069mm.