| Title: | Attenuated sensitivity of ozone to precursors in Beijing-Tianjin-Hebei region with the continuous NO(x) reduction within 2014-2018 |
| Author(s): | Wei W; Wang X; Wang X; Li R; Zhou C; Cheng S; |
| Address: | "Department of Environmental Science and Engineering, Beijing University of Technology, Beijing 100124, China; Key Laboratory of Beijing on Regional Air Pollution Control, Beijing 100124, China. Electronic address: weiwei@bjut.edu.cn. Department of Environmental Science and Engineering, Beijing University of Technology, Beijing 100124, China. Department of Environmental Science and Engineering, Beijing University of Technology, Beijing 100124, China; Key Laboratory of Beijing on Regional Air Pollution Control, Beijing 100124, China. Center for Satellite Application on Ecology and Environment, Beijing 100094, China" |
| DOI: | 10.1016/j.scitotenv.2021.152589 |
| ISSN/ISBN: | 1879-1026 (Electronic) 0048-9697 (Linking) |
| Abstract: | "Facing the elevated surface summer O(3) over North China in recent years with the continuous NO(x) reduction, we conducted the ozone-precursor sensitivity study in summer (July) in Beijing-Tianjin-Hebei region (BTH) under the 2018 and 2014 emissions, based on WRF-Chem model. On 2018 emission condition, 30% precursor reduction simulations presented the positive contribution of VOCs and the negative contribution of NO(x) to daytime O(3). The occurrence probabilities of VOCs-sensitive, NO(x)-titration, mixed sensitive, NO(x)-sensitive, and non-sensitive regimes respectively reached 3-49%, 2-82%, 0-7%, 0-6% and 14-82% in the urban grids, and 2-32%,1-19%, 1-6%, 0-5% and 54-86% in the rural grids. For several widely used photochemical indicators, their values in VOCs-sensitive regime were well separated from those in NO(x)-sensitive regime, but the NO(x)-sensitive values were very similar to the non-sensitive values, which implied the inefficiency of these indicators in indicating NO(x)-sensitive regime. Finally, VOCs-sensitive regime was discerned based on the indicator HCHO/NO(2), occupying about a third of areas in morning and dusk but shrinking to about a tenth of areas in 11:00-16:00 in BTH. And these areas apparently decreased from 2014 emission to 2018 emission. However, the rest areas of this region were under non-sensitive regime but not NO(x)-sensitive regime, for the noticeable O(3) drop never happened in NO(x) reduction scenario. Meanwhile, the modeled O(3)/PAN in the areas under non-sensitive regime exceeded 60, which also implied the minor impact of local photochemistry on O(3) there. Additionally, the responses of daytime O(3) to precursor emissions in the urban grids were calculated, declining by 20.8% for NO(x) and 6.9% for VOCs from 2014 to 2018. Therefore, to solve the ozone pollution problem of BTH, the cross-region strategy coupled with the VOCs and NO(x) co-control will be essential" |
| Keywords: | *Air Pollutants/analysis Beijing China Environmental Monitoring Environmental Pollution *Ozone/analysis *Volatile Organic Compounds/analysis Indicator North China Ozone Photochemical production Sensitive precursor; |
| Notes: | "MedlineWei, Wei Wang, Xingfeng Wang, Xiaoqi Li, Rui Zhou, Chunyan Cheng, Shuiyuan eng Netherlands 2021/12/27 Sci Total Environ. 2022 Mar 20; 813:152589. doi: 10.1016/j.scitotenv.2021.152589. Epub 2021 Dec 23" |
