title: [PM₂.₅ Background Concentration at Different Directions in Beijing in 2013].
abstract: PM₂.₅, background concentration at different directions in 2013 in Beijing was analyzed combining the techniques of mathematical statistics, physical identification and numerical simulation (CMAQ4.7.1) as well as using monitoring data of six PM₂.₅ auto-monitoring sites and five meteorological sites in 2013. Results showed that background concentrations of PM₂.₅ at northwest, northeast, eastern, southeast, southern and southwest boundary sites were between 40.3 and 85.3 µg · m⁻³ in Beijing. From the lowest to the highest, PMPM₂.₅ background concentrations at different sites were: Miyun reservoir, Badaling, Donggaocun, Yufa, Yongledian and Liulihe. Background concentration of PM₂.₅ was the lowest under north wind, then under west wind, and significantly higher under south and east wind. Calculated PM₂.₅ background average concentrations were 6.5-27.9, 22.4-73.4, 67.2-91.7, 40.7-116.1 µg · m⁻³ respectively in different wind directions. Simulated PM₂.₅ background concentration showed a clear north-south gradient distribution and the surrounding area had a notable effect on the spatial distribution of PM₂.₅ background concentration in 2013 in Beijing.
authors.forename: Yun-ting
authors.initials: YT
authors.lastname: Li
authors.forename: Niam-liang
authors.initials: NL
authors.lastname: Cheng
authors.forename: Da-wei
authors.initials: DW
authors.lastname: Zhang
authors.forename: Rui-wen
authors.initials: RW
authors.lastname: Sun
authors.forename: Xin
authors.initials: X
authors.lastname: Dong
authors.forename: Nai-di
authors.initials: ND
authors.lastname: Sun
authors.forename: Chen
authors.initials: C
authors.lastname: Chen
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D000068476:Beijing; D004784:Environmental Monitoring; D052638:Particulate Matter / Q000032:analysis*; D012621:Seasons; D014919:Wind
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter