【摘要】 颗粒物是北京的首要大气污染物,2006年PM10年均浓度超标60%以上.本研究基于颗粒物质量浓度在线监测和逐日TSP的采样分析,结合地面天气形势,论述了北京大气颗粒物污染的区域性特征.首先,北京大气颗粒物污染过程的形成由以冷锋过境为明显标志的周期性的天气系统决定,天气系统的活动尺度决定了颗粒物污染的区域性.其次,从PM2.5/PM10和Pb/Al比值的变化判别出颗粒物污染过程中随着颗粒物浓度的升高,细颗粒物呈现富集趋势;细颗粒物的富集由粗颗粒物的去除和超细颗粒物的生成(核化过程)、以及二次颗粒物的生成所致;污染过程中颗粒物的老化以及化学组成(Pb/Al)的大幅度变化共同表明了北京大气颗粒物来源的区域性本质.更多还原

【Abstract】 Particulate matter is the primary pollutant of the urban atmosphere in Beijing.PM10 was 60% higher than the national second-class standard in 2006.Based on fast-response aerosol concentrations and elemental compositions in daily TSP,this study revealed the regionality of episodic aerosol pollution.First,surface weather patterns indicated that episodic aerosol pollution was affected by the passing of cold fronts caused by the synoptic cycles covering large areas,which naturally resulted in the regionality of aerosol pollution in Beijing.Second,as the episodes progressed,PM2.5/PM10 and Pb/Al increased,which was associated with the removal of coarse particles,nucleation of nanoparticles,and formation of secondary particles.Thus aerosol became finer and aged,which implies that the aerosol in Beijing is a result of regional sources.更多还原