Modeling the biogenic isoprene emission and its impact on ozone pollution in Zhejiang province, China

Chenxi Lou; Fei Jiang; Xudong Tian; Qiaoli Zou; Yanhua Zheng; Yang Shen; Shuzhuang Feng; Jiansong Chen; Lingyu Zhang; Mengwei Jia; Jiawei Xu

doi:10.1016/j.scitotenv.2022.161212

Modeling the biogenic isoprene emission and its impact on ozone pollution in Zhejiang province, China

Sci Total Environ. 2023 Mar 20:865:161212. doi: 10.1016/j.scitotenv.2022.161212. Epub 2022 Dec 28.

Authors

Chenxi Lou¹, Fei Jiang², Xudong Tian³, Qiaoli Zou³, Yanhua Zheng¹, Yang Shen¹, Shuzhuang Feng¹, Jiansong Chen⁴, Lingyu Zhang¹, Mengwei Jia¹, Jiawei Xu⁵

Affiliations

¹ Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology, International Institute for Earth System Science, Nanjing University, Nanjing 210023, China.
² Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology, International Institute for Earth System Science, Nanjing University, Nanjing 210023, China; Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing 210023, China; Frontiers Science Center for Critical Earth Material Cycling, Nanjing University, Nanjing 210023, China. Electronic address: jiangf@nju.edu.cn.
³ Zhejiang Ecological and Environmental Monitoring Center, Hangzhou 310012, China; Zhejiang Key Laboratory of Ecological and Environmental Monitoring, Forewarning and Quality Control, Hangzhou 310012, China.
⁴ Zhejiang Hangzhou Ecological and Environment Monitoring Center, Hangzhou 310007, China.
⁵ School of Atmospheric Sciences, Nanjing University, Nanjing 210023, China.

PMID: 36586687
DOI: 10.1016/j.scitotenv.2022.161212

Abstract

Isoprene is the most abundantly emitted biogenic volatile organic compound (BVOC), which plays an essential role in producing tropospheric ozone (O₃). However, the simulations of isoprene emissions have not been sufficiently verified over Yangtze River Delta (YRD), and few studies have specifically addressed its impact on O₃ formation. In this study, we simulated the isoprene emissions in Zhejiang Province (ZJ), a region with the largest BVOC emission in YRD, in August 2020 using the Model of Emissions of Gases and Aerosols from Nature (MEGAN) and the latest Moderate Resolution Imaging Spectroradiometer (MODIS) products, and investigated its contributions to O₃ using the Weather Research and Forecasting (WRF)-Community Multiscale Air Quality (CMAQ) model. The model has a good performance on isoprene simulations over urban and suburban areas, with mean biases of -0.16-0.12 ppb, but underestimated the concentrations at forest sites (mainly due to bamboo). Regionally, the simulated formaldehyde concentrations over forests agree well with the satellite observations. In August 2020, the total isoprene emission in ZJ was 125.1 GgC, with higher emissions in western ZJ and relatively lower emissions in eastern coastal regions. The spatial pattern of isoprene concentrations is similar to its emissions, and the maximum daytime average concentrations are above 3.5 ppb. The spatial pattern of its contribution to daily maximum 8 h average O₃ concentrations is significantly different from the emissions and concentrations, which shows a higher impact in northern ZJ (>6 ppb) and relatively lower impact in southern ZJ (1-3 ppb). The mean contribution over ZJ is 8.9 %, with daily variation in the range of 3.1 % to 13.4 %. For different cities, the monthly mean contribution is in the range of 4.6 % to 14.3 %, and the maximum daily contribution reaches about 25 %. These findings help understand the summertime O₃ pollution in ZJ and the YRD region of China.

Keywords: Biogenic isoprene; MEGAN; Ozone pollution; WRF-CMAQ.