title: Annual and diurnal variations of gaseous and particulate pollutants in 31 provincial capital cities based on in situ air quality monitoring data from China National Environmental Monitoring Center.
abstract: Long-term air quality data with high temporal and spatial resolutions are needed to understand some important processes affecting the air quality and corresponding environmental and health effects. The annual and diurnal variations of each criteria pollutant including PM2.5 and PM10 (particulate matter with aerodynamic diameter less than 2.5 μm and 10 μm, respectively), CO (carbon monoxide), NO2 (nitrogen dioxide), SO2 (sulfur dioxide) and O3 (ozone) in 31 provincial capital cities between April 2014 and March 2015 were investigated by cluster analysis to evaluate current air pollution situations in China, and the cities were classified as severely, moderately, and slightly polluted cities according to the variations. The concentrations of air pollutants in winter months were significantly higher than those in other months with the exception of O3, and the cities with the highest CO and SO2 concentrations were located in northern China. The annual variation of PM2.5 concentrations in northern cities was bimodal with comparable peaks in October 2014 and January 2015, while that in southern China was unobvious with slightly high PM2.5 concentrations in winter months. The concentrations of particulate matter and trace gases from primary emissions (SO2 and CO) and NO2 were low in the afternoon (~16:00), while diurnal variation of O3 concentrations was opposite to that of other pollutants with the highest values in the afternoon. The most polluted cities were mainly located in North China Plain, while slightly polluted cities mostly focus on southern China and the cities with high altitude such as Lasa. This study provides a basis for the formulation of future urban air pollution control measures in China.
authors.affiliation: Key Laboratory of Land Surface Process and Climate Change in Cold and Arid Regions, Cold & Arid Regions Environmental & Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China. Electronic address: zhaosp@lzb.ac.cn.
authors.forename: Suping
authors.initials: S
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Land Surface Process and Climate Change in Cold and Arid Regions, Cold & Arid Regions Environmental & Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Yu
authors.affiliation: Key Laboratory of Desert and Desertification, Cold & Arid Regions Environmental & Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China; Dunhuang Gobi and Desert Ecological and Environmental Research Station, Cold & Arid Regions Environmental & Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China.
authors.forename: Daiying
authors.initials: D
authors.lastname: Yin
authors.affiliation: The College of Environmental Science & Engineering, Nankai University, Tianjin 300071, China.
authors.forename: Jianjun
authors.initials: J
authors.lastname: He
authors.affiliation: Weather Modification Office, Qinghai Provincial Meteorological Bureau, Xining 810001, China.
authors.forename: Na
authors.initials: N
authors.lastname: Liu
authors.affiliation: Key Laboratory of Desert and Desertification, Cold & Arid Regions Environmental & Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China; Dunhuang Gobi and Desert Ecological and Environmental Research Station, Cold & Arid Regions Environmental & Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China.
authors.forename: Jianjun
authors.initials: J
authors.lastname: Qu
authors.affiliation: Key Laboratory of Desert and Desertification, Cold & Arid Regions Environmental & Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China; Dunhuang Gobi and Desert Ecological and Environmental Research Station, Cold & Arid Regions Environmental & Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China.
authors.forename: Jianhua
authors.initials: J
authors.lastname: Xiao
mesh_terms: D000388:Air / Q000032:analysis* / Q000592:standards; D000393:Air Pollutants / Q000032:analysis*; D002248:Carbon Monoxide / Q000032:analysis; D002681:China; D002947:Cities; D004784:Environmental Monitoring / Q000379:methods*; D005740:Gases / Q000032:analysis*; D015386:Hazardous Substances / Q000032:analysis; D009585:Nitrogen Dioxide / Q000032:analysis; D010126:Ozone / Q000032:analysis; D052638:Particulate Matter / Q000032:analysis*; D012621:Seasons; D013458:Sulfur Dioxide / Q000032:analysis; D014507:Urbanization
chemical_list: D000393:Air Pollutants; D005740:Gases; D015386:Hazardous Substances; D052638:Particulate Matter; D013458:Sulfur Dioxide; D010126:Ozone; D002248:Carbon Monoxide; D009585:Nitrogen Dioxide
keywords: Air pollution; Annual variation; China; Cluster analysis; Diurnal variation