- 1Engineering Research Center of Clean and Low-carbon Technology for Intelligent Transportation, Ministry of Education, School of Environment, Beijing Jiaotong University, Beijing 100044, China (yanyulong@bjtu.edu.cn)
- 2School of Environment, Beijing Jiaotong University, Beijing 100044, China(yanyulong@bjtu.edu.cn)
- 3MOE Key Laboratory of Resources and Environmental System Optimization, College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China(yueyuan03070@163.com)
- 4School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA(ywang@eas.gatech.edu)
Tropospheric ozone (O3) is a typical secondary pollutant and produced by a series of chemical reactions of precursors such as nitrogen oxides (NOx) and volatile organic compounds (VOCs) under light conditions. The emission of precursors in industrial cities is large and complex, and the relationship between O3 and its precursors is not clear, making it is challenged to identify the key factors and source influencing O3 formation. This study used observation-based-model (OBM), based on the precursors’ observation data and chemical mechanism, to analyze O3 sensitivities to VOCs and NOx during summer in a typical industrial city in China. In our research, higher concentrations of O3 precursors were observed during O3 polluted periods in summertime indicating that precursor accumulation contributed to the higher max net (O3) (16.6 ppbv∙h-1) and HOx· concentrations. The important reactions in ROx· recycling was mainly dominated by the precursors of NO, NO2 and alkene, which were mainly discharged from sources caused by the developed industry. Analyses of relative incremental reactivity (RIR) indicated that O3 production during polluted period is in a chemical transition regime and was sensitive to both VOCs (RIR=0.39) and NOx (RIR=0.56), particularly emphasizing the crucial of phased control of O3 precursors. Results from PMF analysis indicated that gasoline vehicle emissions were the major contributor to VOCs (27.0%), followed by coal combustion (20.3%), diesel vehicle emissions (15.9%), industrial processes (15.1%). For NOx, coal combustion (44.0%) and diesel vehicle emissions (35.2%) had the largest contribution, followed by industrial processes (12.5%) and gasoline vehicle emissions (8.3%). Based on PMF results and OBM, O3 source was analyzed used RIR method in this study, and industrial process (36.7%) and biogenic source (24.6%) were the major sources of O3. The sensitivities of O3 formation to these sources depend on if both VOC and NOx sensitivities are considered. Previous studies only considered the influence of VOCs on O3 formation when analyzing the source of O3, but this study indicated that the influence of NOx in industrial cities on O3 formation should not be ignored. Meanwhile, considering only VOCs but not NOx in the analysis of O3 sources will underestimate the emission proportion of anthropogenic sources and overestimate the proportion of biogenic sources, resulting in inaccurate results. Industrial cities are typical cities in transition areas, and the sensitivity of O3 to both VOCs and NOx should also be taken into account when analyzing the source of O3 in transition areas, which can ensure the accuracy of source analysis results. In addition, emission reduction of VOCs and NOx simultaneously should be considered in the control of O3 in transition areas. This study provides an improved direction for the source analysis of O3 in industrial cities and even cities in transition areas.
How to cite: Yan, Y., Niu, Y., Yue, K., Dong, J., Wu, J., Wang, Y., and Peng, L.: Formation sensitivity and source analysis of tropospheric ozone in a typical industrial city in China based on the observation data coupled with chemical mechanism, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6097, https://doi.org/10.5194/egusphere-egu25-6097, 2025.
