Significant decreases in the volatile organic compound concentration, atmospheric oxidation capacity and photochemical reactivity during the National Day holiday over a suburban site in the North China Plain

Yang, Yuan; Wang, Yonghong; Yao, Dan; Zhao, Shanshan; Yang, Shuang-Hong; Ji, Dongsheng; Sun, Jie; Wang, Yinghong; Liu, Zirui; Hu, Bo; Zhang, Renjian; Wang, Yuesi

doi:10.1016/j.envpol.2020.114657

Cited by 38 publications

(14 citation statements)

References 113 publications

(107 reference statements)

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“…During the sampling period, the average values of the total OH reactivity was 45.3 s −1 . In general, the OH reactivity assessed in this paper was much higher than those determined in Shanghai , Chongqing , Shanghai (Zhu et al, 2020) and New York (Ren et al, 2006), but was comparable or lower than those in Xianghe (Yang et al,2020a) and Backgarden (Lou et al, 2010). In Zhengzhou, NO2 made the largest contribution to the total OH reactivity (54%), followed by VOCs (17%), NO (16%), CO (11%), SO2 (3%) and O3 (1%).…”

Section: Oh Reactivity Of Measured Speciescontrasting

confidence: 46%

Measurement report: Intra-, inter-annual variability and source apportionment of VOCs during 2018–2020 in Zhengzhou, Central China

Shang

Wang

et al. 2022

Preprint

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Abstract. Ambient volatile organic compounds (VOCs) were measured continuously to investigate their characteristics, sources, atmospheric oxidation capacity (AOC) and chemical reactivity from January 2018 to December 2020 at an urban site in Zhengzhou, China. In this study, the total concentration of observed VOCs was 38.2 ± 15.6 ppbv during the sampling period, with the characteristics that alkanes were the major VOC species, accounting for 60 % of total VOCs. During the sampling period, the inter-annual variation of VOCs gradually reduced from 45.0 ± 25.2 ppbv in 2018 to 36.7 ± 22.0 ppbv in 2019, and to 30.5 ± 15.4 ppbv in 2020. Ethane, ethene, and propane were the top three abundant species during the three-year observation period. The results showed that total AOC, dominated by OH radical reactions, was 7.4 × 107 molecules cm−3 s−1. The total OH reactivity was 45.3 s−1, and mainly contributed by NOx. The AOC and •OH reactivity exhibited well-defined seasonal and inter-annual patterns. Therefore, the control strategy should focus on key species among inter-annual and seasonal variations. Meanwhile, diagnostic ratios of VOC species indicated VOCs in Zhengzhou were greatly affected by vehicle emissions and liquefied petroleum gas/natural gas (LPG/NG). Positive matrix factorization analysis showed six sources were identified, consisting of industrial sources, solvent use, vehicle exhaust, LPG/NG, coal+biomass burning and biogenic sources. Vehicle emissions, solvent use and LPG/NG made the largest contributions to VOC emission in all three years. The proportion of the contribution of vehicle emissions and LPG/NG has increased with each passing year. However, the proportion of industrial and solvent sources presented a decreasing trend, which is speculated that the policy control effect is remarkable. The effect of VOCs on ozone formation suggests that vehicle emission and solvent utilization were still key sources. Therefore, it is necessary to formulate effective strategies for reducing ground-level O3, and those sources mentioned above should be strictly controlled by the regulatory authorities.

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Section: Oh Reactivity Of Measured Speciescontrasting

confidence: 46%

Measurement report: Intra-, inter-annual variability and source apportionment of VOCs during 2018–2020 in Zhengzhou, Central China

Shang

Wang

et al. 2022

Preprint

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“…Note that the NO x emissions are usually lower by about 10% during the Chinese New Year with less business and industrial activities (Ding et al, 2017). The timeline of NO x emissions in Beijing shows a slightly different pattern with a relatively low reduction during the COVID‐19 lockdown but already strong emission reductions during the politically important “two‐sessions” meeting in March 2019, the most important political meeting of China, and especially the celebration of 70th national anniversary of China around 1 October 2019, when many factories were closed and strict emission regulations were enforced (Yang et al, 2020). Figure 3 also shows that the NO x emissions start to increase again in March, in line with the step‐by‐step recovery of the human activities.…”

Section: Nox Emissions Reductionsmentioning

confidence: 99%

NOx Emissions Reduction and Rebound in China Due to the COVID‐19 Crisis

Ding

Eskes

et al. 2020

Geophysical Research Letters

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During the COVID-19 lockdown (24 January-20 March) in China low air pollution levels were reported in the media as a consequence of reduced economic and social activities. Quantification of the pollution reduction is not straightforward due to effects of transport, meteorology, and chemistry. We have analyzed the NO x emission reductions calculated with an inverse algorithm applied to daily NO 2 observations from TROPOMI onboard the Copernicus Sentinel-5P satellite. This method allows the quantification of emission reductions per city and the analysis of emissions of maritime transport and of the energy sector separately. The reductions we found are 20-50% for cities, about 40% for power plants, and 15-40% for maritime transport depending on the region. The reduction in both emissions and concentrations shows a similar timeline consisting of a sharp reduction (34-50%) around the Spring festival and a slow recovery from mid-February to mid-March.

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“…Note that the NO x emissions are usually lower by about 10% during the Chinese New Year with less business and industrial activities (Ding et al, 2017). The timeline of NO x emissions in Beijing shows a slightly different pattern with a relatively low reduction during the COVID-19 lockdown but already strong emission reductions during the politically important "two-sessions" meeting in March 2019, the most important political meeting of China, and especially the celebration of 70th national anniversary of China around 1 October 2019, when many factories were closed and strict emission regulations were enforced (Yang et al, 2020). Figure 3 also shows that the NO x emissions start to increase again in March, in line with the step-by-step recovery of the human activities.…”

Section: 1029/2020gl089912mentioning

confidence: 99%