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| Titel |
Origin of springtime ozone enhancements in the lower troposphere over Beijing: in situ measurements and model analysis |
| VerfasserIn |
J. Huang, H. Liu, J. H. Crawford, C. Chan, D. B. Considine, Y. Zhang, X. Zheng, C. Zhao, V. Thouret, S. J. Oltmans, S. C. Liu, D. B. A. Jones, S. D. Steenrod, M. R. Damon |
| 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 ; 15, no. 9 ; Nr. 15, no. 9 (2015-05-11), S.5161-5179 |
| Datensatznummer |
250119701
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| Publikation (Nr.) |
 copernicus.org/acp-15-5161-2015.pdf |
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| Zusammenfassung |
| Ozone (O3) concentrations in the lower troposphere
(LT) over Beijing have significantly increased over the past 2 decades as
a result of rapid industrialization in China, with important implications
for regional air quality and the photochemistry of the background troposphere.
We characterize the vertical distribution of lower-tropospheric (0–6 km)
O3 over Beijing using observations from 16 ozonesonde soundings
during a field campaign in April–May 2005 and MOZAIC (Measurement of Ozone
and Water Vapor by Airbus In-Service Aircraft) over 13
days in the same period. We focus on the origin of LT O3 enhancements
observed over Beijing, particularly in May. We use a global 3-D chemistry
and transport model (GEOS-Chem CTM; GEOS – Goddard Earth Observing
System) driven by assimilated meteorological
fields to examine the transport pathways for O3 pollution and to quantify
the sources contributing to O3 and its enhancements in the springtime
LT over Beijing. Output from the Global Modeling Initiative (GMI) CTM is
also used. High O3 concentrations (up to 94.7 ppbv) were frequently
observed at the altitude of ~ 1.5–2 km. The CTMs captured the
timing of the occurrences but significantly underestimated their magnitude.
GEOS-Chem simulations and a case study showed that O3 produced in the
Asian troposphere (especially from Asian anthropogenic pollution) made major
contributions to the observed O3 enhancements. Contributions from
anthropogenic pollution in the European and North American troposphere were
reduced during these events, in contrast with days without O3
enhancements when contributions from Europe and North America were
substantial. The O3 enhancements typically occurred under southerly
wind and warmer conditions. It is suggested that an earlier onset of the
Asian summer monsoon would cause more O3 enhancement events in the
LT over the North China Plain in late spring and early
summer. |
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