title: Quantifying sources of elemental carbon over the Guanzhong Basin of China: A consistent network of measurements and WRF-Chem modeling.
abstract: We conducted a year-long WRF-Chem (Weather Research and Forecasting Chemical) model simulation of elemental carbon (EC) aerosol and compared the modeling results to the surface EC measurements in the Guanzhong (GZ) Basin of China. The main goals of this study were to quantify the individual contributions of different EC sources to EC pollution, and to find the major cause of the EC pollution in this region. The EC measurements were simultaneously conducted at 10 urban, rural, and background sites over the GZ Basin from May 2013 to April 2014, and provided a good base against which to evaluate model simulation. The model evaluation showed that the calculated annual mean EC concentration was 5.1 μgC m(-3), which was consistent with the observed value of 5.3 μgC m(-3). Moreover, the model result also reproduced the magnitude of measured EC in all seasons (regression slope = 0.98-1.03), as well as the spatial and temporal variations (r = 0.55-0.78). We conducted several sensitivity studies to quantify the individual contributions of EC sources to EC pollution. The sensitivity simulations showed that the local and outside sources contributed about 60% and 40% to the annual mean EC concentration, respectively, implying that local sources were the major EC pollution contributors in the GZ Basin. Among the local sources, residential sources contributed the most, followed by industry and transportation sources. A further analysis suggested that a 50% reduction of industry or transportation emissions only caused a 6% decrease in the annual mean EC concentration, while a 50% reduction of residential emissions reduced the winter surface EC concentration by up to 25%. In respect to the serious air pollution problems (including EC pollution) in the GZ Basin, our findings can provide an insightful view on local air pollution control strategies.
authors.affiliation: Key Lab of Aerosol Chemistry & Physics, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, 710061, China; Now at Department of Atmospheric Sciences, National Taiwan University, Taipei, 10617, Taiwan.
authors.forename: Nan
authors.initials: N
authors.lastname: Li
authors.affiliation: Now at Department of Atmospheric Sciences, National Taiwan University, Taipei, 10617, Taiwan.
authors.forename: Qingyang
authors.initials: Q
authors.lastname: He
authors.affiliation: Key Lab of Aerosol Chemistry & Physics, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, 710061, China; Center for Excellence in Urban Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China; National Center for Atmospheric Research, Boulder, CO 80303, USA. Electronic address: xxtie@ucar.edu.
authors.forename: Xuexi
authors.initials: X
authors.lastname: Tie
authors.affiliation: Key Lab of Aerosol Chemistry & Physics, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, 710061, China; Institute of Global Environmental Change, Xi'an Jiaotong University, Xi'an, 710049, China.
authors.forename: Junji
authors.initials: J
authors.lastname: Cao
authors.affiliation: Key Lab of Aerosol Chemistry & Physics, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, 710061, China.
authors.forename: Suixin
authors.initials: S
authors.lastname: Liu
authors.affiliation: Key Lab of Aerosol Chemistry & Physics, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, 710061, China.
authors.forename: Qiyuan
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Key Lab of Aerosol Chemistry & Physics, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, 710061, China.
authors.forename: Guohui
authors.initials: G
authors.lastname: Li
authors.affiliation: Key Lab of Aerosol Chemistry & Physics, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, 710061, China; Laboratory of Atmospheric Chemistry, Paul Scherrer Institute, 5232 Villigen, Switzerland.
authors.forename: Rujin
authors.initials: R
authors.lastname: Huang
authors.affiliation: Department of Environmental Sciences and Engineering, Tsinghua University, Beijing, 100084, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhang
mesh_terms: D000336:Aerosols / Q000032:analysis; D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000517:prevention & control; D002244:Carbon / Q000032:analysis*; D002681:China; D004784:Environmental Monitoring / Q000379:methods; D008956:Models, Chemical; D012621:Seasons
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D002244:Carbon
keywords: Elemental carbon; Source apportionment; The Guanzhong Basin; WRF-Chem