Elucidating the effects of covid-19 lockdowns in the UK on the o3-nox-voc relationship

Simple item page
dc.contributor.authorShallcross, Dudley
dc.contributor.authorHolland, Rayne
dc.contributor.authorSeifert, Katya
dc.date.accessioned2024-09-16T13:18:48Z
dc.date.available2024-09-16T13:18:48Z
dc.date.issued2024
dc.description.abstractThe unprecedented reductions in anthropogenic emissions over the COVID-19 lockdowns were utilised to investigate the response of ozone (O3) concentrations to changes in its precursors across various UK sites. Ozone, volatile organic compounds (VOCs) and NOx (NO+NO2) data were obtained for a 3-year period encompassing the pandemic period (January 2019–December 2021), as well as a pre-pandemic year (2017), to better understand the contribution of precursor emissions to O3 fluctuations. Compared with pre-lockdown levels, NO and NO2 declined by up to 63% and 42%, respectively, over the lockdown periods, with the most significant changes in pollutant concentrations recorded across the urban traffic sites. O3 levels correspondingly increased by up to 30%, consistent with decreases in the [NO]/[NO2] ratio for O3 concentration response. Analysis of the response of O3 concentrations to the NOx reductions suggested that urban traffic, suburban background and suburban industrial sites operate under VOC-limited regimes, while urban background, urban industrial and rural background sites are NOx-limited. This was in agreement with the [VOC]/[NOx] ratios determined for the London Marylebone Road (LMR; urban traffic) site and the Chilbolton Observatory (CO; rural background) site, which produced values below and above 8, respectively. Conversely, [VOC]/[NOx] ratios for the London Eltham (LE; suburban background) site indicated NOx-sensitivity, which may suggest the [VOC]/[NOx] ratio for O3 concentration response may have had a slight NOx-sensitive bias. Furthermore, O3 concentration response with [NO]/[NO2] and [VOC]/[NOx] were also investigated to determine their relevance and accuracy in identifying O3-NOx-VOC relationships across UK sites. While the results obtained via utilisation of these metrics would suggest a shift in photochemical regime, it is likely that variation in O3 during this period was primarily driven by shifts in oxidant (OX; NO2 + O3) equilibrium as a result of decreasing NO2, with increased O3 transported from Europe likely having some influence.
dc.identifier.citationHolland, R., Seifert, K., Saboya, E., Khan, M.A.H., Derwent, R.G. and Shallcross, D.E., 2024. Elucidating the Effects of COVID-19 Lockdowns in the UK on the O3-NOx-VOC Relationship. Atmosphere, 15(5), p.607.
dc.identifier.urihttps://doi.org/10.3390/atmos15050607
dc.identifier.urihttps://hdl.handle.net/10566/16160
dc.language.isoen
dc.publisherMultidisciplinary Digital Publishing Institute (MDPI)
dc.subjectCOVID-19
dc.subjectNOx-sensitivity
dc.subjectO3-NOx-VOC relationship
dc.subjectOxidant
dc.subjectRural background site
dc.titleElucidating the effects of covid-19 lockdowns in the UK on the o3-nox-voc relationship
dc.typeArticle

Files

Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
shallcross_elucidating_the_effects_of_covid-19_2024.pdf
Size:
5.28 MB
Format:
Adobe Portable Document Format
Download
License bundle
Now showing 1 - 1 of 1
No Thumbnail Available
Name:
license.txt
Size:
1.71 KB
Format:
Item-specific license agreed upon to submission
Description:
Download

Collections

Research Articles (Chemistry)