title: [Analysis of the impact of two typical air pollution events on the air quality of Nanjing].
abstract: Nanjing and the surrounding area have experienced two consecutive serious air pollution events from late October to early November in 2009. The first event was long-lasting haze pollution, and the second event was resulted from the mixed impact of crop residue burning and local transportation. The effects of regional transport and local sources on the two events were discussed by cluster analysis, using surface meteorological observations, air pollution index, satellite remote sensing of fire hot spots data and back trajectory model. The results showed that the accumulation-mode aerosol number concentrations were higher than those of any other aerosol modes in the two pollution processes. The peak value of aerosol particle number concentrations shifted to large particle size compare with the previous studies in this area. The ratio of SO4(2-)/NO3(-) was 1.30 and 0.99, indicating that stationary sources were more important than traffic sources in the first event and the reverse in the second event. Affected by the local sources from east and south, the particle counts below 0.1 microm gradually accumulated in the first event. The second event was mainly affected by a short-distance transport from northeast and local sources from southwest, especially south, the concentration of aerosol particles was higher than those in other directions, indicating that the sources of crop residue burning were mainly in this direction.
authors.affiliation: Key Laboratory of Meteorological Disaster of Ministry of Education, Nanjing University of Information Science and Technology, Nanjing 210044, China. wf2775@gmail.com
authors.forename: Fei
authors.initials: F
authors.lastname: Wang
authors.forename: Bin
authors.initials: B
authors.lastname: Zhu
authors.forename: Han-Qing
authors.initials: HQ
authors.lastname: Kang
authors.forename: Jin-Hui
authors.initials: JH
authors.lastname: Gao
authors.forename: Yin
authors.initials: Y
authors.lastname: Wang
authors.forename: Qi
authors.initials: Q
authors.lastname: Jiang
mesh_terms: D000336:Aerosols / Q000032:analysis*; D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000032:analysis; D002681:China; D004784:Environmental Monitoring / Q000379:methods*; D017745:Incineration; D009566:Nitrates / Q000032:analysis; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis; D013458:Sulfur Dioxide / Q000032:analysis; D001335:Vehicle Emissions / Q000032:analysis*
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D009566:Nitrates; D052638:Particulate Matter; D001335:Vehicle Emissions; D013458:Sulfur Dioxide