[Spatiotemporal Distributions and Variations in Summertime Ozone Photochemical Production Regimes over Shanxi].
Huan Jing Ke Xue
; 45(8): 4432-4439, 2024 Aug 08.
Article
em Zh
| MEDLINE
| ID: mdl-39168663
ABSTRACT
Satellite-based formaldehydeï¼HCHOï¼columns and tropospheric nitrogen dioxide columns were observed using the Ozone Monitoring Instrumentï¼OMIï¼ï¼and groundbased observations of ozoneï¼O3ï¼for May-August from 2013 to 2022 were connected to calculate the threshold values of the HCHO to NO2 ratioï¼FNRï¼in Shanxi Province. Thenï¼the spatiotemporal distributions and variations in summertime ozone photochemical production regimes were analyzed. The results showed thatï¼â The volatile organic compoundï¼VOCï¼ -sensitive regime areaï¼FNR < 2.3ï¼was obviously reducedï¼while the VOCs-NOx transitional regimeï¼FNR between 2.3-4.1ï¼area increased in the early years and then decreasedï¼ and NO x -sensitive regime area expanded significantly in summer from 2013 to 2022 over Shanxi Province. â¡ The increased summertime FNR during 2013 to 2019 was associated with the co-effect of increased HCHO columns and decreased tropospheric NO2 columns. The Shanxi Province was generally under an NOx regime since 2016ï¼which reflected the remarkable effect of NO x emission reductionsï¼howeverï¼there was a shift from a VOC-sensitive regime to a VOCs-NOx transitional regimeï¼in which O3 pollution aggravation was widespread under the background of decreased NOx emissions. The decrease in O3 concentration during 2020 to 2022 followed the synergistical declines in HCHO columns and tropospheric NO2 columns. ⢠The O3 weekend effects were reversed in Linfen and Yuncheng but were persistent in the other nine cities. Satellite-based weekend HCHO and NO2 levels were higher than those on weekdays in some cities of Shanxi Provinceï¼indicating that the O3 weekend effect was not only dependent on the changes of precursors emissions but was also closely related to O3 photochemical production sensitivity. The results indicated the necessity of simultaneous controls in NOx emissions and VOCs emissions for ozone abatement plans over Shanxi Province. In additionï¼Taiyuanï¼Yangquanï¼Yunchengï¼and Jincheng should continue to promote reduction in NOx emissions.
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MEDLINE
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Zh
Ano de publicação:
2024
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Article