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https://doi.org/10.5194/egusphere-2023-1358
https://doi.org/10.5194/egusphere-2023-1358
02 Aug 2023
 | 02 Aug 2023

Current status of model predictions on volatile organic compounds and impacts on surface ozone predictions during summer in China

Yongliang She, Jingyi Li, Xiaopu Lyu, Hai Guo, Momei Qin, Xiaodong Xie, Kangjia Gong, Fei Ye, Jianjiong Mao, Lin Huang, and Jianlin Hu

Abstract. Volatile organic compounds (VOCs) play a crucial role in the formation of tropospheric ozone (O3) and secondary organic aerosols. VOC emissions are generally considered to have larger uncertainties compared to other pollutants, such as sulphur dioxide and fine particulate matter (PM2.5). Although predictions of O3 and PM2.5 have been extensively evaluated in air quality modelling studies, there has been limited reporting on the evaluation of VOCs, mainly due to a lack of routine VOCs measurements at multiple sites. In this study, we utilized VOCs measurements from the ATMSYC project at 28 sites across China and assessed the predicted VOCs concentrations using the Community Multiscale Air Quality (CMAQ) model with the widely used Multi-resolution Emission Inventory for China (MEIC). The ratio of predicted to observed total VOCs was found to be 0.74 ± 0.40, with underpredictions ranging from 2.05 to 50.61 ppbv (5.77 % to 85.40 %) at 24 sites. A greater bias in VOCs predictions was observed in industrial cities in the north and southwest, such as Jinan, Shijiazhuang, Lanzhou, Chengdu, and Guiyang. In terms of different VOC components, alkanes, alkenes, non-naphthalene aromatics (ARO2MN), and alkynes were consistently underpredicted, with prediction to observation ratios of 0.53 ± 0.38, 0.51 ± 0.48, 0.31 ± 0.38, and 0.41 ± 0.47, respectively. Sensitivity experiments were conducted to assess the impact of the VOCs prediction bias on O3 predictions. While emission adjustments improved the model performance for VOCs, resulting in a ratio of total VOCs to 0.86 ± 0.47, they also exacerbated O3 overprediction relative to the base case by 0.62 % to 6.27 % across the sites. This study demonstrates that current modelling setups and emission inventories are likely to underpredict VOCs concentrations, and this underprediction of VOCs contributes to lower O3 predictions in China.

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Journal article(s) based on this preprint

10 Jan 2024
Current status of model predictions of volatile organic compounds and impacts on surface ozone predictions during summer in China
Yongliang She, Jingyi Li, Xiaopu Lyu, Hai Guo, Momei Qin, Xiaodong Xie, Kangjia Gong, Fei Ye, Jianjiong Mao, Lin Huang, and Jianlin Hu
Atmos. Chem. Phys., 24, 219–233, https://doi.org/10.5194/acp-24-219-2024,https://doi.org/10.5194/acp-24-219-2024, 2024
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The requested preprint has a corresponding peer-reviewed final revised paper. You are encouraged to refer to the final revised version.

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The evaluation of predicted VOC in current chemical transport model is limited in China due to...
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