title: Local and regional contributions to fine particulate matter in Beijing during heavy haze episodes.
abstract: In order to alleviate extreme haze pollution, understanding the origin of fine particulate matter (PM2.5) is crucial. In this study, we applied Particulate Matter Source Apportionment Technology (PSAT) in CAMx (Comprehensive Air Quality Model with Extensions) to quantify the impacts of emissions from different regions on PM2.5concentrations in Beijing for haze episodes during January 6-23, 2013. Emission inventory was developed by Tsinghua University. Evolution of local and Regional contributions during local and non-local dominated haze episodes were discussed, separately. In the meanwhile, average contribution of other every city in Jing-Jin-Ji region to PM2.5concentrations larger than 75μgm-3in Beijing urban for each range of local contribution percent was analyzed. The results indicate that local emissions contributed 83.6% of PM2.5at the urban center of Beijing, while regional transport from surrounding cities and parts of Shandong, Henan and Anhui provinces contributed 9.4%; long-range transport contributed the remaining 7.0% mainly from areas >750km away to the south of Beijing during this study period. Compared to non-local-dominated haze episodes, local-dominated heavy haze episodes in Beijing were easily resulted from unfavorable meteorological conditions with much lower PBL and wind velocity. Furthermore, local contribution is more easily to cause a sharp increase or sharp reduction of PM2.5concentration in central Beijing, reflecting that Beijing local has much stronger potential to form extremely heavy haze episodes. The results indicated that controlling local emissions is a much more important measure to alleviate the extreme haze episodes in Beijing, like that on the night of Jan 12, 2013. Furthermore, emission control in Jing-Jin-Ji region, especially in Tangshan, Tianjin, Baoding, Langfang, Shijiazhuang and Cangzhou, as well as Henan and Shandong province, are important to reduce the PM2.5concentrations and the occurrence of haze episodes in Beijing.
authors.affiliation: School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China.
authors.forename: Yangjun
authors.initials: Y
authors.lastname: Wang
authors.affiliation: School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China.
authors.forename: Shengwei
authors.initials: S
authors.lastname: Bao
authors.affiliation: State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China. Electronic address: shxwang@tsinghua.edu.cn.
authors.forename: Shuxiao
authors.initials: S
authors.lastname: Wang
authors.affiliation: School of Civil & Environmental Engineering, Institute of Georgia Technology, Atlanta, GA 30332, USA.
authors.forename: Yongtao
authors.initials: Y
authors.lastname: Hu
authors.affiliation: School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Shi
authors.affiliation: State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
authors.forename: Jiandong
authors.initials: J
authors.lastname: Wang
authors.affiliation: State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Zhao
authors.affiliation: State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
authors.forename: Jingkun
authors.initials: J
authors.lastname: Jiang
authors.affiliation: College of Environmental Science and Engineering, Peking University, Beijing 100084, China.
authors.forename: Mei
authors.initials: M
authors.lastname: Zheng
authors.affiliation: School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China.
authors.forename: Minghong
authors.initials: M
authors.lastname: Wu
authors.affiliation: School of Civil & Environmental Engineering, Institute of Georgia Technology, Atlanta, GA 30332, USA.
authors.forename: Armistead G
authors.initials: AG
authors.lastname: Russell
authors.affiliation: School of Earth and Atmospheric Sciences, Institute of Georgia Technology, Atlanta, GA 30332, USA.
authors.forename: Yuhang
authors.initials: Y
authors.lastname: Wang
authors.affiliation: State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
authors.forename: Jiming
authors.initials: J
authors.lastname: Hao
keywords: Beijing; CAMx; PM(2.5); Source apportionment