@article {LI2024174405,
	title = {Radical chemistry and VOCs-NOx-O3-nitrate sensitivity in the polluted atmosphere of a suburban site in the North China Plain},
	journal = {Science of The Total Environment},
	volume = {947},
	year = {2024},
	pages = {174405},
	abstract = {In this study, the chemical mechanisms of O3 and nitrate formation as well as the control strategy were investigated based on extensive observations in Tai\&$\#$039;an city in the NCP and an observation-constrained box model. The results showed that O3 pollution was severe with the maximum hourly O3 concentration reaching 150~ppb. Higher O3 concentration was typically accompanied by higher PM2.5 concentrations, which could be ascribed to the common precursors of VOCs and NOx. The modeled averaged peak concentrations of OH, HO2, and RO2 were relatively higher compared to previous observations, indicating strong atmospheric oxidation capacity in the study area. The ROx production rate increased from 2.8~ppb~h-1 to 5~ppb~h-1 from the clean case to the heavily polluted case and was dominated by HONO photolysis, followed by HCHO photolysis. The contribution of radical-self combination to radical termination gradually exceeded NO2~+~OH from clean to polluted cases, indicating that O3 formation shifted to a more NOx-limited regime. The O3 production rate increased from 14~ppb~h-1 to 22~ppb~h-1 from clean to heavily polluted cases. The relative incremental reactivity (RIR) results showed that VOCs and NOx had comparable RIR values during most days, which suggested that decreasing VOCs or NOx was both effective in alleviating O3 pollution. In addition, HCHO, with the largest RIR value, made important contribution to O3 production. The Empirical Kinetic Modeling Approach (EKMA) revealed that synergistic control of O3 and nitrate can be achieved by decreasing both NOx and VOCs emissions (e.g., alkenes) with the ratio of 3:1. This study emphasized the importance of NOx abatement for the synergistic control of O3 and nitrate pollution in the Tai\&$\#$039;an area as the sustained emissions control has shifted the O3 and nitrate formation to a more NOx-limited regime.},
	keywords = {ekma, Ozone formation, radical chemistry, RIR, Synergistic control of O and nitrate},
	issn = {0048-9697},
	doi = {https://doi.org/10.1016/j.scitotenv.2024.174405},
	url = {https://www.sciencedirect.com/science/article/pii/S0048969724045534},
	author = {Yang Li and Ye, Can and Ma, Xuefei and Zhaofeng Tan and Yang, Xinping and Zhai, Tianyu and Yuhan Liu and Lu, Keding and Yuanhang Zhang}
}
