Co-occurrence of ozone and PM2.5 pollution in urban/non-urban areas in eastern China from 2013 to 2020: Roles of meteorology and anthropogenic emissions

Huibin Dai; Hong Liao; Ye Wang; Jing Qian

doi:10.1016/j.scitotenv.2024.171687

Co-occurrence of ozone and PM_2.5 pollution in urban/non-urban areas in eastern China from 2013 to 2020: Roles of meteorology and anthropogenic emissions

Sci Total Environ. 2024 May 10:924:171687. doi: 10.1016/j.scitotenv.2024.171687. Epub 2024 Mar 13.

Authors

Huibin Dai¹, Hong Liao², Ye Wang³, Jing Qian¹

Affiliations

¹ Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing 210044, China.
² Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing 210044, China. Electronic address: hongliao@nuist.edu.cn.
³ Key Laboratory of Meteorological Disaster, Ministry of Education (KLME)/Joint International Research Laboratory of Climate and Environment Change (ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD), Nanjing University of Information Science and Technology, Nanjing 210044, China.

PMID: 38485008
DOI: 10.1016/j.scitotenv.2024.171687

Abstract

We applied a three-dimensional (3-D) global chemical transport model (GEOS-Chem) to evaluate the influences of meteorology and anthropogenic emissions on the co-occurrence of ozone (O₃) and fine particulate matter (PM_2.5) pollution day (O₃-PM_2.5PD) in urban and non-urban areas of the Beijing-Tianjin-Hebei (BTH) and Yangtze River Delta (YRD) regions during the warm season (April-October) from 2013 to 2020. The model captured the observed O₃-PM_2.5PD trends and spatial distributions well. From 2013 to 2020, with changes in both anthropogenic emissions and meteorology, the simulated values of O₃-PM_2.5PD in the urban (non-urban) areas of the BTH and YRD regions were 424.8 (330.1) and 309.3 (286.9) days, respectively, suggesting that pollution in non-urban areas also warrants attention. The trends in the simulated values of O₃-PM_2.5PD were -0.14 and -0.15 (+1.18 and +0.81) days yr^-1 in the BTH (YRD) urban and non-urban areas, respectively. Sensitivity simulations revealed that changes in anthropogenic emissions decreased the occurrence of O₃-PM_2.5PD, with trends of -0.99 and -1.23 (-1.47 and -1.92) days yr^-1 in the BTH (YRD) urban and non-urban areas, respectively. Conversely, meteorological conditions could exacerbate the frequency of O₃-PM_2.5PD, especially in the urban YRD areas, but less notably in the urban BTH areas, with trends of +2.11 and +0.30 days yr^-1, respectively, owing to changes in meteorology only. The increases in T2m_max and T2m were the main meteorological factors affecting O₃-PM_2.5PD in most BTH and YRD areas. Furthermore, by conducting sensitivity experiments with different levels of pollutant precursor reductions in 2020, we found that volatile organic compound (VOC) reductions primarily benefited O₃-PM_2.5PD decreases in urban areas and that NO_x reductions more notably influenced those in non-urban areas, especially in the YRD region. Simultaneously, reducing VOC and NO_x emissions by 50 % resulted in considerable O₃-PM_2.5PD decreases (58.8-72.6 %) in the urban and non-urban areas of the BTH and YRD regions. The results of this study have important implications for the control of O₃-PM_2.5PD in the urban and non-urban areas of the BTH and YRD regions.

Keywords: Emission reductions; Meteorology; Ozone and PM(2.5) pollution.