TY - JOUR
T1 - Diverse response of surface ozone to COVID-19 lockdown in China
AU - Liu, Yiming
AU - Wang, Tao
AU - Stavrakou, Trissevgeni
AU - Elguindi, Nellie
AU - Doumbia, Thierno
AU - Granier, Claire
AU - Bouarar, Idir
AU - Gaubert, Benjamin
AU - Brasseur, Guy P.
N1 - Funding Information:
This work was supported by the Hong Kong Research Grants Council ( T24-504/17-N and A-PolyU502/16 ) and the National Natural Science Foundation of China ( 91844301 ). B.G. acknowledges support by the National Center for Atmospheric Research , which is a major facility sponsored by the National Science Foundation under cooperative agreement no. 1852977 . We would like to thank Prof. Qiang Zhang from Tsinghua University for providing the emission inventory.
Funding Information:
This work was supported by the Hong Kong Research Grants Council (T24-504/17-N and A-PolyU502/16) and the National Natural Science Foundation of China (91844301). B.G. acknowledges support by the National Center for Atmospheric Research, which is a major facility sponsored by the National Science Foundation under cooperative agreement no. 1852977. We would like to thank Prof. Qiang Zhang from Tsinghua University for providing the emission inventory.
Publisher Copyright:
© 2021 Elsevier B.V.
PY - 2021/10/1
Y1 - 2021/10/1
N2 - Ozone (O3) is a key oxidant and pollutant in the lower atmosphere. Significant increases in surface O3 have been reported in many cities during the COVID-19 lockdown. Here we conduct comprehensive observation and modeling analyses of surface O3 across China for periods before and during the lockdown. We find that daytime O3 decreased in the subtropical south, in contrast to increases in most other regions. Meteorological changes and emission reductions both contributed to the O3 changes, with a larger impact from the former especially in central China. The plunge in nitrogen oxide (NOx) emission contributed to O3 increases in populated regions, whereas the reduction in volatile organic compounds (VOC) contributed to O3 decreases across the country. Due to a decreasing level of NOx saturation from north to south, the emission reduction in NOx (46%) and VOC (32%) contributed to net O3 increases in north China; the opposite effects of NOx decrease (49%) and VOC decrease (24%) balanced out in central China, whereas the comparable decreases (45–55%) in these two precursors contributed to net O3 declines in south China. Our study highlights the complex dependence of O3 on its precursors and the importance of meteorology in the short-term O3 variability.
AB - Ozone (O3) is a key oxidant and pollutant in the lower atmosphere. Significant increases in surface O3 have been reported in many cities during the COVID-19 lockdown. Here we conduct comprehensive observation and modeling analyses of surface O3 across China for periods before and during the lockdown. We find that daytime O3 decreased in the subtropical south, in contrast to increases in most other regions. Meteorological changes and emission reductions both contributed to the O3 changes, with a larger impact from the former especially in central China. The plunge in nitrogen oxide (NOx) emission contributed to O3 increases in populated regions, whereas the reduction in volatile organic compounds (VOC) contributed to O3 decreases across the country. Due to a decreasing level of NOx saturation from north to south, the emission reduction in NOx (46%) and VOC (32%) contributed to net O3 increases in north China; the opposite effects of NOx decrease (49%) and VOC decrease (24%) balanced out in central China, whereas the comparable decreases (45–55%) in these two precursors contributed to net O3 declines in south China. Our study highlights the complex dependence of O3 on its precursors and the importance of meteorology in the short-term O3 variability.
KW - COVID-19
KW - Emission reduction
KW - Meteorological condition
KW - Surface ozone
UR - http://www.scopus.com/inward/record.url?scp=85107683747&partnerID=8YFLogxK
U2 - 10.1016/j.scitotenv.2021.147739
DO - 10.1016/j.scitotenv.2021.147739
M3 - Journal article
AN - SCOPUS:85107683747
SN - 0048-9697
VL - 789
JO - Science of the Total Environment
JF - Science of the Total Environment
M1 - 147739
ER -
