Newland, MJ, Bryant, DJ, Dunmore, RE et al. (28 more authors) (2021) Low-NO atmospheric oxidation pathways in a polluted megacity. Atmospheric Chemistry and Physics, 21 (3). pp. 1613-1625. ISSN 1680-7316
Abstract
The impact of emissions of volatile organic compounds (VOCs) to the atmosphere on the production of secondary pollutants, such as ozone and secondary organic aerosol (SOA), is mediated by the concentration of nitric oxide (NO). Polluted urban atmospheres are typically considered to be “high-NO” environments, while remote regions such as rainforests, with minimal anthropogenic influences, are considered to be “low NO”. However, our observations from central Beijing show that this simplistic separation of regimes is flawed. Despite being in one of the largest megacities in the world, we observe formation of gas- and aerosol-phase oxidation products usually associated with low-NO “rainforest-like” atmospheric oxidation pathways during the afternoon, caused by extreme suppression of NO concentrations at this time. Box model calculations suggest that during the morning high-NO chemistry predominates (95 %) but in the afternoon low-NO chemistry plays a greater role (30 %). Current emissions inventories are applied in the GEOS-Chem model which shows that such models, when run at the regional scale, fail to accurately predict such an extreme diurnal cycle in the NO concentration. With increasing global emphasis on reducing air pollution, it is crucial for the modelling tools used to develop urban air quality policy to be able to accurately represent such extreme diurnal variations in NO to accurately predict the formation of pollutants such as SOA and ozone.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © Author(s) 2021. This work is distributed under the Creative Commons Attribution 4.0 License. |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Chemistry (Leeds) > Physical Chemistry (Leeds) |
Funding Information: | Funder Grant number NERC (Natural Environment Research Council) NE/N006895/1 |
Depositing User: | Symplectic Publications |
Date Deposited: | 02 Mar 2021 13:05 |
Last Modified: | 02 Mar 2021 13:05 |
Status: | Published |
Publisher: | Copernicus Publications |
Identification Number: | 10.5194/acp-21-1613-2021 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:171665 |