title: Impacts of regional transport on black carbon in Huairou, Beijing, China.
abstract: The 22ndAsia-Pacific Economic Cooperation (APEC) Conference was held near Yanqi Lake, Huairou, in Beijing, China during November 10-11, 2014. To guarantee haze-free days during the APEC Conference, the Beijing government and the governments of the surrounding provinces implemented a series of controls. Three months of Aethalometer 880 nm black carbon (BC) measurements were examined to understand the hourly fluctuations in BC concentrations that resulted from emission controls and meteorology changes. Measurements were collected at the University of Chinese Academy of Sciences near the APEC Conference site and in Central Beijing at the Institute of Remote Sensing and Digital Earth of the Chinese Academy of Sciences. Synoptic conditions are successfully represented through analysis of backward trajectories in six cluster groups. The clusters are identified based on air mass transport from various areas such as Inner Mongolia, Russia, three northeastern provinces, and Hebei industrial areas, to the measurement sites. Air pollution control measures during the APEC Conference significantly reduced BC at the conference site (Huairou) and in Central Beijing, with greater reductions in BC concentrations at the conference site than in Central Beijing. The highest BC concentrations in Huairou were associated with air masses originating from Central Beijing rather than from the Hebei industrial region. The success of the control measures implemented in Beijing and the surrounding regions demonstrates that BC concentrations can be effectively reduced to protect human health and mitigate regional climate forcing. This study also demonstrates the need for regional strategies to reduce BC concentrations, since urban areas like Beijing are sources as well as downwind receptors of emissions.
authors.affiliation: College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China. Electronic address: wangyuqin11@mails.ucas.ac.cn.
authors.forename: Yuqin
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Earth and Atmospheric Sciences, Saint Louis University, St. Louis, MO 63108, USA.
authors.forename: Benjamin
authors.initials: B
authors.lastname: de Foy
authors.affiliation: Civil and Environmental Engineering Department, University of Wisconsin-Madison, Madison, WI 53706, USA; Environmental Chemistry and Technology Program, University of Wisconsin-Madison, Madison, WI 53706, USA.
authors.forename: James J
authors.initials: JJ
authors.lastname: Schauer
authors.affiliation: Environmental Chemistry and Technology Program, University of Wisconsin-Madison, Madison, WI 53706, USA; Water Science and Engineering Laboratory, University of Wisconsin-Madison, Madison, WI 53706, USA.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Olson
authors.affiliation: College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Remote Sensing Science, Institute of Remote Sensing Applications, Chinese Academy of Sciences, Beijing, 100094, China.
authors.forename: Zhengqiang
authors.initials: Z
authors.lastname: Li
authors.affiliation: College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China; Huairou Eco-Environmental Observatory, Chinese Academy of Sciences, Beijing, 101408, China; CAS Center for Excellence in Regional Atmospheric Environment, Chinese Academy of Sciences, Xiamen, 361021, China. Electronic address: yxzhang@ucas.ac.cn.
authors.forename: Yuanxun
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D001208:Asia; D000068476:Beijing; D002244:Carbon / Q000032:analysis; D002681:China; D003247:Conservation of Natural Resources; D004784:Environmental Monitoring; D006801:Humans; D007221:Industry; D008956:Models, Chemical; D052638:Particulate Matter / Q000032:analysis; D012426:Russia; D053260:Soot / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter; D053260:Soot; D002244:Carbon
keywords: APEC; BC; CFA; Control and non-control periods; Huairou; RTA