Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
Atmos. Chem. Phys., 17, 10633-10649, 2017
https://doi.org/10.5194/acp-17-10633-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
11 Sep 2017
The levels, variation characteristics, and sources of atmospheric non-methane hydrocarbon compounds during wintertime in Beijing, China
Chengtang Liu1,3,*, Zhuobiao Ma1,3,*, Yujing Mu1,2,3,4, Junfeng Liu1,2,3, Chenglong Zhang1,2,3, Yuanyuan Zhang1,2,3, Pengfei Liu1,3, and Hongxing Zhang1,5 1Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
2Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
3University of Chinese Academy of Sciences, Beijing 100085, China
4National Engineering Laboratory for VOCs Pollution Control Material & Technology, University of Chinese Academy of Sciences, Beijing 100049, China
5Beijing Urban Ecosystem Research Station, Beijing, 100085, China
*These authors contributed equally to this work.
Abstract. Atmospheric non-methane hydrocarbon compounds (NMHCs) were measured at a sampling site in Beijing city from 15 December 2015 to 14 January 2016 to recognize their pollution levels, variation characteristics, and sources. We quantified 53 NMHCs, and the proportions of alkanes, alkenes, acetylene, and aromatics to the total NMHCs were 49.8–55.8, 21.5–24.7, 13.5–15.9, and 9.3–10.7 %, respectively. The variation trends in the NMHC concentrations were basically identical and exhibited remarkable fluctuation, which was mainly ascribed to the variation in meteorological conditions, especially wind speed. The diurnal variations in NMHCs on clear days exhibited two peaks during the morning and evening rush hours, whereas the rush hours' peaks diminished or even disappeared on the haze days, implying that the relative contribution of the vehicular emissions to atmospheric NMHCs depended on the pollution status. Two evident peaks of the propane ∕ propene ratios appeared in the early morning before sun rise and at noontime on clear days, whereas only one peak occurred in the afternoon during the haze days, which were attributed to the relatively fast reactions of propene with OH, NO3, and O3. Based on the chemical kinetic equations, the daytime OH concentrations were calculated to be in the range of 3. 47 × 105–1. 04 × 106 molecules cm−3 on clear days and 6. 42 × 105–2. 35 × 106 molecules cm−3 on haze days. The nighttime NO3 concentrations were calculated to be in the range of 2. 82 × 109–4. 86 × 109 molecules cm−3 on clear days. The correlation coefficients of typical hydrocarbon pairs (benzene ∕ toluene, o-xylene ∕ m,p-xylene, isopentane ∕ n-pentane, etc.) revealed that vehicular emissions and coal combustion were important sources for atmospheric NMHCs in Beijing during the wintertime. Five major emission sources for atmospheric NMHCs in Beijing during the wintertime were further identified by positive matrix factorization (PMF), including gasoline-related emissions (gasoline exhaust and evaporation), coal combustion, diesel exhaust, acetylene-related emissions, and consumer and household products. Coal combustion (probably domestic coal combustion) was found to make the greatest contribution (29.6–33.4 %) to atmospheric NMHCs during haze days.

Citation: Liu, C., Ma, Z., Mu, Y., Liu, J., Zhang, C., Zhang, Y., Liu, P., and Zhang, H.: The levels, variation characteristics, and sources of atmospheric non-methane hydrocarbon compounds during wintertime in Beijing, China, Atmos. Chem. Phys., 17, 10633-10649, https://doi.org/10.5194/acp-17-10633-2017, 2017.
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Short summary
NMHCs were measured during wintertime in Beijing to recognize their pollution levels, variation characteristics, and sources. The difference of the diurnal variations in NMHCs between clear days and haze days indicated that the relative contribution of vehicular emissions to NMHCs depended on the pollution status. Both the correlation coefficients of hydrocarbon pairs and PMF analysis revealed that coal combustion was an important source for atmospheric NMHCs, especially on haze days.
NMHCs were measured during wintertime in Beijing to recognize their pollution levels, variation...
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