针对2011年12月初北京及华北持续近一周的严重大雾天气这一热点事件,从城市群大雾过程气溶胶区域影响的视角,基于"973"项目"北京及周边地区大气-水-土环境污染机理与调控原理"的研究工作,就北京及周边地区大雾天气与大气气溶胶区域影响的关系等方面进行了讨论.研究表明,北京城市大雾前低空SO2和NO2浓度存在"积聚"与"突增"现象.北京及周边地区冬季雾日数和气溶胶光学厚度则呈正相关,并具有"同位相"的年际变化趋势.研究同时发现北京及其南部周边的冬季气溶胶高值区呈南北向带状分布,其与北京周边居民户数高值区有所吻合,反映了冬季北京城市气溶胶颗粒物的远距离影响源区及大尺度输送效应.统计分析指出,冬季北京气溶胶颗粒物PM10、PM2.5主要影响成分是SO2和NOX,且有关研究也表明,电厂、采暖和工业面源是SO2的三大本地排放源,而机动车、电厂、工业为NOX的三大本地排放源,上述大气PM10、PM2.5主成分污染源亦与雾水样本化学分析结果相吻合,即冬季由于燃煤在生活能源中的比例较大,北京雾水中硫元素和碳元素的含量都较高.因此,北京冬季大雾不仅与北京城区气溶胶及其污染排放影响存在相关关系,而且与北京周边天津、河北、山东等地气溶胶及大气污染物的远距离输送和气溶胶区域影响效应有着重要的联系.因此,北京雾霾天气及相关大气污染的治理工作首先要着眼于局地污染物的减排,但同时如何做好区域大气污染的协同治理也是不容忽视的问题.
Aiming at the hotspot event of the heavy fog process which persisted a week in Beijing and North China in early December of 2011,from the viewpoint of regional impact of aerosol on heavy fog in the city agglomeration and based on the research works of the Major State Basic Research Development Program 973 Project named "Air,Water and Soil Environmental Pollution Mechanism and Its Regulating-Controlling Principles in Beijing and Its Ambient Area",the relationship between heavy fog and regional impact of aerosol in Beijing and its ambient area were discussed.The results suggest that before the fog onset over Beijing,the pollutants like SO2 and NO2 have been accumulated at a lower level and show an abrupt increase.In Beijing and its peripheral area,winter fog days are positively correlated with aerosol optical depth(AOD) and there is "in-phase" character of the interannual variations of them.It indicates that the variations of aerosol have impacts on changes of fog days in this area.It can be found from the distributive feature of the AOD that the high value area(Beijing and its south peripheral area) exhibits a relatively stable south-north zonal pattern,i.e.the AOD high value range of the Beijing might extend to Hebei,Henan,Shandong and Shanxi provinces,etc.,and the spatial distribution of the high value area of AOD is associated with that of the high value area of resident family number.It suggests that the emission sources for winter Beijing atmospheric aerosols particle might be remotely traced to the south peripheral greater-scale spatial range and the large scale transportation also have some effects.Statistical analysis results show that the impacts of SO2 and NOX dominate in the component structure of winter PM10 and PM2.5 aerosol particle,which accords with the relevant research results about the local emission sources of air pollution in Beijing that power plants,heating,and industrial surface source were three major local emission sources of SO2,and automobiles,power plants and industries