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| Titel |
Surface ozone trend details and interpretations in Beijing, 2001–2006 |
| VerfasserIn |
G. Tang, X. Li, Y. Wang, J. Xin, X. Ren |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 9, no. 22 ; Nr. 9, no. 22 (2009-11-20), S.8813-8823 |
| Datensatznummer |
250007760
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| Publikation (Nr.) |
 copernicus.org/acp-9-8813-2009.pdf |
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| Zusammenfassung |
| Beijing is a megacity situated in the rapidly developing
Beijing-Tianjin-Hebei region of northern China. In this study, we analyze
data on ozone and nitrogen oxide levels obtained at six urban sites in
Beijing between the months of July and September. Our goal is to investigate
average trends and interpretations over the 2001–2006 period. Average
concentrations of NOx (NOx=NO+NO2), O3, and Ox
(Ox=O3+NO2) were 49.2±5.9 ppbv, 26.6±2.8 ppbv, and
60.3±1.9 ppbv, respectively. NOx concentrations decreased linearly at a
rate of 3.9±0.5 ppbv/yr after 2002, while ozone concentrations
increased at a rate of 1.1±0.5 ppbv/yr during 2001–2006, and Ox
concentrations remained nearly constant. The reduction of NOx emissions and
elevated non-methane hydrocarbon (NMHCs) emissions may have contributed to
the increased O3 concentrations in Beijing. When the contributions from
Beijing's urban and surrounding areas were disaggregated via trajectory
cluster analysis, daily maximum and average Ox concentrations attributable
to Beijing's local emissions increased linearly at rates of 1.3±0.6 ppbv/yr
and 0.8±0.6 ppbv/yr, while the Ox concentrations attributable
to regional areas decreased linearly at rates of 0.6±0.3 ppbv/yr and
0.5±0.3 ppbv/yr, respectively. The decrease in Ox concentrations of the
surrounding areas was found to counteract increasing Beijing urban Ox
production, leading to nearly constant Ox concentrations in the Beijing
region over the study period. Our results may be helpful for redefining
government strategies to control the photochemical formation of air
pollutants in the Beijing region. Our conclusions have relevance for
developing megacities worldwide. |
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