Dr. Xiaojun Zheng Published article on Environmental Sciences Europe with the title of "Spatiotemporal characterization of aerosols and trace gases over the Yangtze River Delta region, China: impact of trans-boundary pollution and meteorology". Post-doctoral, Z. Javed as the first author, Prof. D.L. Du and X.J. Zheng as the co-corresponding authors.
Abstract: The spatiotemporal variation of observed trace gases (NO2, SO2, O3) and particulate matter (PM2.5, PM10) were investigated over cities of Yangtze River Delta (YRD) region including Nanjing, Hefei, Shanghai and Hangzhou. Furthermore, the characteristics of diferent pollution episodes, i.e., haze events (visibility 40 µg/m3) and complex pollution episodes (PM2.5 > 35 µg/m3 and O3>160 µg/m3) were studied over the cities of the YRD region. The impact of China clean air action plan on concentration of aerosols and trace gases is examined. The impacts of trans-boundary pollution and diferent meteorological conditions were also examined. The highest annual mean concentrations of PM2.5, PM10, NO2 and O3 were found for 2019 over all the cities. The annual mean concentrations of PM2.5, PM10, and NO2 showed continuous declines from 2019 to 2021 due to emission control measures and implementation of the Clean Air Action plan over all the cities of the YRD region. The annual mean O3 levels showed a decline in 2020 over all the cities of YRD region, which is unprecedented since the beginning of the China’s National environmental monitoring program since 2013. However, a slight increase in annual O3 was observed in 2021. The highest overall means of PM2.5, PM10, SO2, and NO2 were observed over Hefei, whereas the highest O3 levels were found in Nanjing. Despite the strict control measures, PM2.5 and PM10 concentrations exceeded the Grade-1 National Ambient Air Quality Standards (NAAQS) and WHO (World Health Organization) guidelines over all the cities of the YRD region. The number of haze days was higher in Hefei and Nanjing, whereas the complex pollution episodes or concurrent occurrence of O3 and PM2.5 pollution days were higher in Hangzhou and Shanghai. The in situ data for SO2 and NO2 showed strong correlation with Tropospheric Monitoring Instrument (TROPOMI) satellite data.
Acknowledgements: This study was supported by the Jiangsu Funding Program for Excellent Postdoctoral Talent (Grant No. 2022ZB651), National Natural Science Foundation of China [Grant No. 32071521], the Scientifc Research Foundation for Senior Talent of Jiangsu University, China [Grant No. 20JDG067], the Jiangsu Province “Double Innovation PhD” Grant, Special Project of Jiangsu Distinguished Professor [R2018T22], and the Startup Foundation for Introduction Talent of NUIST [2017r107].
DOI: https://doi.org/10.1186/s12302-022-00668-2.
