Characteristics of aerosol size distributions and new particle formation in the summer in Beijing
Characteristics of aerosol size distributions and new particle formation in the summer in Beijing
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DOI：
10.1029/2008jd010894
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发表时间：
2009-01
影响因子：
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通讯作者：
Dingli Yue;Min Hu;Zhijun Wu;Zhibin Wang;Song Guo;B. Wehner;A. Nowak;P. Achtert;A. Wiedensohler-A.-Wie
中科院分区：
文献类型：
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作者：
Dingli Yue;Min Hu;Zhijun Wu;Zhibin Wang;Song Guo;B. Wehner;A. Nowak;P. Achtert;A. Wiedensohler-A.-Wie
[1]2006年北京及周边地区空气质量研究活动（CAREBeijing-2006）主要研究区域气溶胶对北京市空气污染的影响。对城市气溶胶进行了详细的表征。颗粒大小分布也进行了比较，在北京大学（北大）的城市站点以南约50公里的区域站点（Yufa）的测量。在北京大学，总粒子数和体积浓度分别为（1.8 ± 0.8）× 104 cm−3和83.5 ± 57.9 μm3 cm−3。2004年、2005年和2006年连续三个夏季的天数被归类为PM10超过150 μg m−3的污染天数和PM10较低的非污染天数。在非污染天，颗粒数粒径分布显示出最大值在约60 nm与艾特肯模式粒子占主导地位的数浓度。在污染天，积累模式的颗粒物的贡献增加，移动的最大数粒径分布超过80 nm。在气象条件停滞的污染日，二次气溶胶占主导地位，SO 42-，NO3-和NH 4+占累积模式颗粒质量的60%以上。两个地点的粒度分布相似。在Yufa的总颗粒的数量和体积浓度分别降低了6%和12%，积累模式的颗粒分别降低了2%和15%。这意味着北京的空气污染主要是一个区域性问题。区域累积模态粒子是评价大气质量的一个重要指标，因为它们对能见度和总质量浓度的影响最大。污染日的数量和体积浓度分别为5 × 103 cm−3和30 μm3 cm−3。在CAREBeijing-2006期间，在北京大学和玉佛学院观测到了5个新的粒子形成事件，这些事件都是连续平稳增长的。这些NPF事件是区域性或半区域性的。PKU的生长速率范围为1.2至5.6 nm h-1，形成速率范围为1.1至22.4 cm-3 s-1。SO 42-、NH 4+和草酸盐可能是NPF事件的重要贡献者。
[1] The Campaigns of Air Quality Research in Beijing and Surrounding Region 2006 (CAREBeijing-2006) were mainly focused on the influence of the regional aerosol on the air pollution in Beijing. The urban aerosol was characterized in detail. The particle size distributions were also compared to those measured at a regional site (Yufa) approximately 50 km south of the urban site at Peking University (PKU). At PKU, total particle number and volume concentrations were (1.8 ± 0.8) × 104 cm−3 and 83.5 ± 57.9 μm3 cm−3, respectively. Days in three consecutive summers of 2004, 2005, and 2006 were classified as polluted days with PM10 over 150 μg m−3 and nonpolluted days with lower PM10. On nonpolluted days, particle number size distributions showed a maximum at about 60 nm with Aitken mode particles dominating number concentration. On polluted days, the contribution of accumulation mode particles increased, shifting the maximum of the number size distribution to over 80 nm. On polluted days with stagnant meteorological conditions, secondary aerosol dominated, with SO42−, NO3−, and NH4+ accounting for over 60% of accumulation mode particle mass. Particle number size distributions at both sites were similar. Number and volume concentrations of total particles at Yufa were 6% and 12% lower, respectively; those of accumulation mode particles were 2% and 15% lower. This means that air pollution in Beijing is mainly a regional problem. The regional accumulation mode particles are a metric for assessing the air quality since they influence most the visibility and total mass concentration. Their number and volume concentrations on polluted days were 5 × 103 cm−3 and 30 μm3 cm−3, respectively. Five new particle formation (NPF) events with continuous smooth growth were observed at both PKU and Yufa during CAREBeijing-2006. These NPF events are regional or semiregional. Growth rates at PKU ranged from 1.2 to 5.6 nm h−1, and formation rates ranged from 1.1 to 22.4 cm−3 s−1. SO42−, NH4+, and oxalate might be important contributors to NPF events.