Chemistry of Atmospheric Fine Particles During the COVID-19 Pandemic in a Megacity of Eastern China
© 2020. The Authors.
| Publié dans: | Geophysical research letters. - 1984. - 48(2021), 2 vom: 28. Jan., Seite 2020GL091611 |
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| Auteur principal: | |
| Autres auteurs: | , , , , , , , , , , , , , , , |
| Format: | Article en ligne |
| Langue: | English |
| Publié: |
2021
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| Accès à la collection: | Geophysical research letters |
| Sujets: | Journal Article COVID‐19 air pollution chemical composition fine particles megacity |
| Résumé: | © 2020. The Authors. Air pollution in megacities represents one of the greatest environmental challenges. Our observed results show that the dramatic NOx decrease (77%) led to significant O3 increases (a factor of 2) during the COVID-19 lockdown in megacity Hangzhou, China. Model simulations further demonstrate large increases of daytime OH and HO2 radicals and nighttime NO3 radical, which can promote the gas-phase reaction and nocturnal multiphase chemistry. Therefore, enhanced NO3 - and SO4 2- formation was observed during the COVID-19 lockdown because of the enhanced oxidizing capacity. The PM2.5 decrease was only partially offset by enhanced aerosol formation with its reduction reaching 50%. In particular, NO3 - decreased largely by 68%. PM2.5 chemical analysis reveals that vehicular emissions mainly contributed to PM2.5 under normal conditions in Hangzhou. Whereas, stationary sources dominated the residual PM2.5 during the COVID-19 lockdown. This study provides evidence that large reductions in vehicular emissions can effectively mitigate air pollution in megacities |
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| Description: | Date Revised 30.03.2024 published: Print-Electronic figshare: 10.6084/m9.figshare.12919013 Citation Status PubMed-not-MEDLINE |
| ISSN: | 0094-8276 |
| DOI: | 10.1029/2020GL091611 |