title: Source appointment of fine particle number and volume concentration during severe haze pollution in Beijing in January 2013.
abstract: Extreme haze episodes repeatedly shrouded Beijing during the winter of 2012-2013, causing major environmental and health problems. To better understand these extreme events, particle number size distribution (PNSD) and particle chemical composition (PCC) data collected in an intensive winter campaign in an urban site of Beijing were used to investigate the sources of ambient fine particles. Positive matrix factorization (PMF) analysis resolved a total of eight factors: two traffic factors, combustion factors, secondary aerosol, two accumulation mode aerosol factors, road dust, and long-range transported (LRT) dust. Traffic emissions (54%) and combustion aerosol (27%) were found to be the most important sources for particle number concentration, whereas combustion aerosol (33%) and accumulation mode aerosol (37%) dominated particle volume concentrations. Chemical compositions and sources of fine particles changed dynamically in the haze episodes. An enhanced role of secondary inorganic species was observed in the formation of haze pollution. Regional transport played an important role for high particles, contribution of which was on average up to 24-49% during the haze episodes. Secondary aerosols from urban background presented the largest contributions (45%) for the rapid increase of fine particles in the severest haze episode. In addition, the invasion of LRT dust aerosols further elevated the fine particles during the extreme haze episode. Our results showed a clear impact of regional transport on the local air pollution, suggesting the importance of regional-scale emission control measures in the local air quality management of Beijing.
authors.affiliation: State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry (LAPC), Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, 100029, China.
authors.forename: Zirui
authors.initials: Z
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry (LAPC), Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, 100029, China. wys@mail.iap.ac.cn.
authors.forename: Yuesi
authors.initials: Y
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry (LAPC), Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, 100029, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Hu
authors.affiliation: State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry (LAPC), Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, 100029, China.
authors.forename: Dongsheng
authors.initials: D
authors.lastname: Ji
authors.affiliation: State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry (LAPC), Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, 100029, China.
authors.forename: Junke
authors.initials: J
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry (LAPC), Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, 100029, China.
authors.forename: Fangkun
authors.initials: F
authors.lastname: Wu
authors.affiliation: Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100085, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Wan
authors.affiliation: College of Atmospheric Science, Lanzhou University, Lanzhou, 730000, China.
authors.forename: Yonghong
authors.initials: Y
authors.lastname: Wang
mesh_terms: D000336:Aerosols / Q000032:analysis; D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000706:statistics & numerical data; D000068476:Beijing; D004391:Dust / Q000032:analysis*; D004784:Environmental Monitoring; D005163:Factor Analysis, Statistical; D010316:Particle Size; D012621:Seasons; D012905:Smog / Q000032:analysis*; D001335:Vehicle Emissions / Q000032:analysis; D014887:Weather
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D004391:Dust; D012905:Smog; D001335:Vehicle Emissions
keywords: Haze episodes; Particle number size distribution; Positive matrix factorization; Source apportionment