Characteristics of aerosol size distributions and new particle formation in the summer in Beijing

摘要: [1] The Campaigns of Air Quality Research in Beijing and Surrounding Region 2006 (CAREBeijing-2006) were mainly focused on the influence regional aerosol air pollution Beijing. The urban was characterized detail. particle size distributions also compared to those measured at a site (Yufa) approximately 50 km south Peking University (PKU). At PKU, total number volume concentrations (1.8 ± 0.8) × 104 cm−3 83.5 57.9 μm3 cm−3, respectively. Days three consecutive summers 2004, 2005, classified as polluted days with PM10 over 150 μg m−3 nonpolluted lower PM10. On days, showed maximum about 60 nm Aitken mode particles dominating concentration. contribution accumulation increased, shifting distribution 80 nm. stagnant meteorological conditions, secondary dominated, SO42−, NO3−, NH4+ accounting for 60% mass. Particle both sites similar. Number Yufa 6% 12% lower, respectively; 2% 15% lower. This means that is problem. are metric assessing quality since they most visibility mass Their 5 103 30 Five new formation (NPF) events continuous smooth growth observed PKU during CAREBeijing-2006. These NPF or semiregional. Growth rates ranged from 1.2 5.6 h−1, 1.1 22.4 s−1. NH4+, oxalate might be important contributors events.