| Title: | Characterizing nitrate radical budget trends in Beijing during 2013-2019 |
| Author(s): | Wang H; Lu K; Chen S; Li X; Zeng L; Hu M; Zhang Y; |
| Address: | "State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China; School of Atmospheric Sciences, Sun Yat-sen University, Guangzhou 510275, China; Guangdong Provincial Observation and Research Station for Climate Environment and Air Quality Change in the Pearl River Estuary, Key Laboratory of Tropical Atmosphere-Ocean System, Ministry of Education, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519082, China. State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China. Electronic address: k.lu@pku.edu.cn. State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China" |
| DOI: | 10.1016/j.scitotenv.2021.148869 |
| ISSN/ISBN: | 1879-1026 (Electronic) 0048-9697 (Linking) |
| Abstract: | "Nitrate (NO(3)) radical is an important oxidant in the atmosphere as it regulates the NO(x) budget and impacts secondary pollutant formation. Here, a long-term observational dataset of NO(3)-related species at an urban site in Beijing was used to investigate changes in the NO(3) budget and their atmospheric impacts during 2013-2019, in this period the Clean Air Actions Plan was carried out in China. We found that (1) changes in NO(3) precursors (NO(2) and O(3)) led to a significant increase in NO(3) formation in the surface layer in winter but a decrease in summer; (2) a reduction in NO(x) promoted thermal equilibrium, favoring the formation of NO(3) rather than dinitrogen pentoxide (N(2)O(5)). The simultaneous decrease in PM(2.5), during these years, further weakened the N(2)O(5) heterogeneous uptake; (3) a box model simulation revealed that both the reactions of NO(3) with volatile organic compounds (VOC) and N(2)O(5) uptake were weakened in summer, implying that the policy actions implemented help to moderate secondary aerosol formation caused by NO(3) and N(2)O(5) chemistry in summer; and (4) during winter, both NO(3) + VOC and N(2)O(5) uptake were enhanced. Specifically, for the N(2)O(5) uptake, the rapid increase in NO(3) production, or to some extent, NO(3) oxidation capacity, far outweighed the negative shift effect, leading to a net enhancement of N(2)O(5) uptake in winter, which indicates that the action policy implemented led to an adverse effect on particulate nitrate formation via N(2)O(5) uptake in winter. This may explain the persistent winter particulate nitrate pollution in recent years. Our results highlight the systematic changes in the NO(3) budget between 2013 and 2019 in Beijing, which subsequently affect secondary aerosol formation in different seasons" |
| Keywords: | *Air Pollutants/analysis Beijing Environmental Monitoring *Nitrates/analysis Particulate Matter/analysis Dinitrogen pentoxide Nitrate pollution Nitrate radial budget Trend analysis; |
| Notes: | "MedlineWang, Haichao Lu, Keding Chen, Shiyi Li, Xin Zeng, Limin Hu, Min Zhang, Yuanhang eng Netherlands 2021/07/31 Sci Total Environ. 2021 Nov 15; 795:148869. doi: 10.1016/j.scitotenv.2021.148869. Epub 2021 Jul 7" |
