Xu W.,Beijing Environmental Protection Monitoring Center |
Li Y.,Beijing Environmental Protection Monitoring Center |
Sun R.,Beijing Environmental Protection Monitoring Center |
Dong X.,Beijing Environmental Protection Monitoring Center |
Qiu Q.,Beijing Environmental Protection Monitoring Center
Huanjing Kexue Xuebao/Acta Scientiae Circumstantiae | Year: 2014
An air pollution episode occurred in Beijing from 18 to 21 March 2011. This study analyzed the synoptic situation, transport pathway of dust, and variation characteristics of air pollutant concentration with pollutants and meteorological measurement data, lidar observation and a backward trajectory model. Results showed that after lifted up at the source regions, the sand-dust first transported through Beijing, then stuck at Bohai Bay and Korean peninsula. Pushed by the Bohai weak high pressure system, the sand-dust flew back to Beijing and led to severe air pollution. During the backflow process, the increase of PM10 firstly appeared in the east of Beijing, then moved to the central urban area, and arrived the west of Beijing finally. The concentration of PM10 was above 350 μg·m-3 for consecutive 16 hours, with the maximum value up to 571 μg·m-3. The hourly concentration of SO2 and NO2 changed synchronously with PM10. In addition to the contribution of sand-dust during the backflow pollution process, anthropogenic emissions from surrounding areas were another important factor.