title: Ground-level ozone in the Pearl River Delta and the roles of VOC and NO(x) in its production.
abstract: In many regions of China, very rapid economic growth has been accompanied by air pollution caused by vehicle emissions. In one of these regions, the Pearl River Delta, the variations of ground-level ozone and its precursors were investigated. Overall, the ambient concentrations of NO(2) increased quickly between 1995 and 1996, but then slightly decreased due to stringent nitrogen oxide (NO(x)) emission controls. Nonetheless, ambient NO(2) levels in the Pearl River Delta remained high. The regional average concentrations of volatile organic compounds (VOCs) were 290 ppbC in summer and 190 ppbC in autumn. Local emissions and long-distance transportation of pollutants play important roles in the regional distribution of VOCs. Ambient O(3) production is significant in urban areas and also downwind of cities. The relative incremental reactivities (RIRs), determined by an observation-based model, showed that ground-level ozone formation in the Guangzhou urban area is generally limited by the concentrations of VOCs, but there are also measurable impacts of NO(x).
authors.affiliation: State Joint Key Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China. mshao@pku.edu.cn
authors.forename: Min
authors.initials: M
authors.lastname: Shao
authors.forename: Yuanhang
authors.initials: Y
authors.lastname: Zhang
authors.forename: Limin
authors.initials: L
authors.lastname: Zeng
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Tang
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.forename: Liuju
authors.initials: L
authors.lastname: Zhong
authors.forename: Boguang
authors.initials: B
authors.lastname: Wang
mesh_terms: D000388:Air / Q000032:analysis*; D000397:Air Pollution / Q000032:analysis*; D002681:China; D002980:Climate; D005843:Geography; D009569:Nitric Oxide / Q000032:analysis; D009585:Nitrogen Dioxide / Q000032:analysis; D009589:Nitrogen Oxides / Q000032:analysis*; D009930:Organic Chemicals / Q000032:analysis*; D010126:Ozone / Q000032:analysis*; D045483:Rivers / Q000737:chemistry*; D012621:Seasons; D013696:Temperature; D013997:Time Factors; D014835:Volatilization
chemical_list: D009589:Nitrogen Oxides; D009930:Organic Chemicals; D009569:Nitric Oxide; D010126:Ozone; D009585:Nitrogen Dioxide