气流输送对乌鲁木齐市PM10、PM2.5和PM1.0质量浓度的影响

应用聚类分析法,对乌鲁木齐市2009-2010年逐日气流72 h后向轨迹按季节进行分类,结合对应时段的PM10、PM2.5和PM1.0观测数据,分析了不同气流输送轨迹对研究区3粒径段气溶胶浓度的影响.结果表明:冬季,气流对研究区气溶胶的搬运、稀释作用明显,气溶胶浓度平均值与对应气流移动速度成反比；春季,流经沙漠区的气流分组对应气溶胶浓度平均值偏高,且气溶胶谱分布向粗模态移动；夏季,大气清洁,携带城市气溶胶的西北气流对研究区气溶胶浓度平均值影响较大,未携带外源物质的几组气流流速与气溶胶浓度基本呈负相关；秋季,研究区受外源气溶胶影响不大,且气流对污染物的输送、稀释作用也不强烈,各分组气溶胶浓度差别不大.

The Influences of Airflow on the Concentrations of PM10,PM2.5 and PM1.0 in Urumqi,Xinjiang,China

With a cluster analysis on the 72 h back trajectories of the daily ariflow and the observed data of PM10, PM2.5 and PM1.0 in Urumqi city in each season during 2009-2010, we explored the effects of the airflows on the concentrations of the three PMs. The results showed that: In winter, the air pollutent could be carried away or diffused by the airflow, the mass concentration of the particle aerosols with different size had a negative correlation with the airflow speeds. In spring, the airflows passing through the desert areas could carry dust aerosols to the study city, making the particle spectrum distribution move to the corse fraction. In summer, the atmosphere was clean, the NW airflows, which carried urban aerosols, had great influences on the background concentration, while the airflow from the other directions, which didn't carry extra-sourced contamination, basicly had a negative correlation with the aerosol concentrations. In autumn, the extra-sourced contamination didn't had great influences on the city, and the air flows were not so strong, so there were no significant differences between the concentrations of the three PMs.