title: Source identification of reactive hydrocarbons and oxygenated VOCs in the summertime in Beijing.
abstract: It is important to identify the sources of reactive volatile organic compounds (VOCs) in Beijing for effective ground-level ozone abatement. In this paper, semihourly measurements of hydrocarbons and oxygenated VOCs (OVOCs) were taken at an urban site in Beijing in August2005. C2-C5 alkenes, isoprene, and C1-C3 aldehydes were determined as "key reactive species" by their OH loss rates. Principal component analysis (PCA) was used to define the major sources of reactive species and to classify the dominant air mass types at the sampling site. Vehicle exhaust was the largest contributor to reactive alkenes. More aged air masses with enriched OVOCs traveled mainly from the east or southeast of Beijing. The OVOC sources were estimated by a least-squares fit approach and included primary emissions, secondary sources, and background. Approximately half of the C1-C3 aldehydes were attributed to secondary sources, while regional background accounted for 21-23% of the mixing ratios of aldehydes. Primary anthropogenic emissions were comparable to biogenic contributions (10-16%).
authors.affiliation: State Joint Key Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.forename: Min
authors.initials: M
authors.lastname: Shao
authors.forename: William C
authors.initials: WC
authors.lastname: Kuster
authors.forename: Paul D
authors.initials: PD
authors.lastname: Goldan
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Li
authors.forename: Sihua
authors.initials: S
authors.lastname: Lu
authors.forename: Joost A
authors.initials: JA
authors.lastname: de Gouw
mesh_terms: D000079:Acetaldehyde / Q000032:analysis; D002070:Butadienes / Q000032:analysis; D002074:Butanones / Q000032:analysis; D002681:China; D045782:Hemiterpenes / Q000032:analysis; D006813:Humidity; D006838:Hydrocarbons / Q000032:analysis*; D017665:Hydroxyl Radical / Q000737:chemistry; D000432:Methanol / Q000032:analysis; D010100:Oxygen / Q000032:analysis*; D010420:Pentanes / Q000032:analysis; D011891:Rain; D012621:Seasons; D013696:Temperature; D013997:Time Factors; D055549:Volatile Organic Compounds / Q000032:analysis*; D014919:Wind
chemical_list: D002070:Butadienes; D002074:Butanones; D045782:Hemiterpenes; D006838:Hydrocarbons; D010420:Pentanes; D055549:Volatile Organic Compounds; C005059:isoprene; D017665:Hydroxyl Radical; C057920:3-buten-2-one; D000079:Acetaldehyde; D010100:Oxygen; D000432:Methanol