 |
| Titel |
Ozone weekend effects in the Beijing–Tianjin–Hebei metropolitan area, China |
| VerfasserIn |
Y. H. Wang, B. Hu, D. S. Ji, Z. R. Liu, G. Q. Tang, J. Y. Xin, H. X. Zhang, T. Song, L. L. Wang, W. K. Gao, X. K. Wang, Y. S. Wang |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 14, no. 5 ; Nr. 14, no. 5 (2014-03-10), S.2419-2429 |
| Datensatznummer |
250118468
|
| Publikation (Nr.) |
 copernicus.org/acp-14-2419-2014.pdf |
|
|
|
|
|
| Zusammenfassung |
The ozone weekend effect (OWE) was first investigated in the metropolitan
area of Beijing–Tianjin–Hebei (BTH), China, using in situ measurements from
the Atmospheric Environment Monitoring Network from July 2009 to August
2011. The results indicate that there is an obvious weekly periodical
variation in the surface ozone concentration. There is a lower ozone
concentration from Wednesday to Friday (weekday) and a higher concentration
from Saturday to Monday (weekend) at all the locations of the study.
NOx also displays a weekly cycle, with the maximum level occurring on
weekdays and the minimum level on weekends, especially later on Sunday night
and early Monday morning. This pattern may be responsible for the higher
concentration of ozone on weekends. Additionally, the vertical variations in
O3 and NOx from the 8 m, 47 m, 120 m and 280 m observation
platforms on the 325 m Beijing meteorological tower displayed obvious weekly
cycles that corresponded to the surface results.
A smaller decrease in volatile organic compounds (VOCs; using CO as a proxy) and much lower NOx
concentrations on the weekend may lead to higher VOC / NOx ratio, which can
enhance the ozone production efficiency in VOC-limited regime areas.
Additionally, a clear weekly cycle in the fine aerosol concentration was
observed, with maximum values occurring on weekdays and minimum values
occurring on weekends. Higher concentrations of aerosol on weekdays can
reduce the UV radiation flux by scattering or absorbing, which leads to a
decrease in the ozone production efficiency. A significant weekly cycle in
UV radiation, consistent with the aerosol concentration, was discovered at
the Beijing meteorological tower site (BJT), validating the assumption. A comprehensive understanding of
the ozone weekend effect in the BTH area can provide deep insights into
controlling photochemical pollution. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|