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| Titel |
IASI observations of seasonal and day-to-day variations of tropospheric ozone over three highly populated areas of China: Beijing, Shanghai, and Hong Kong |
| VerfasserIn |
G. Dufour, M. Eremenko, J. Orphal, J.-M. Flaud |
| 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 ; 10, no. 8 ; Nr. 10, no. 8 (2010-04-23), S.3787-3801 |
| Datensatznummer |
250008372
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| Publikation (Nr.) |
 copernicus.org/acp-10-3787-2010.pdf |
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| Zusammenfassung |
| IASI observations of tropospheric ozone over the Beijing, Shanghai and Hong
Kong areas during one year (2008) have been analysed, demonstrating the
capability of space-borne infrared nadir measurements to probe seasonal
and even day-to-day variations of lower tropospheric ozone (0–6 km partial
columns) on the regional scale of highly populated areas. The monthly
variations of lower tropospheric ozone retrieved from IASI clearly show the
influence of the Asian summer monsoon that brings clean air masses from the
Pacific during summer. They exhibit indeed a sharp ozone maximum in late
spring and early summer (May–June) followed by a summer minimum. The time
periods and the intensities of the maxima and of the decreases are
latitude-dependent: they are more pronounced in Hong Kong and Shanghai than
in Beijing. Moreover, IASI provides the opportunity to follow the spatial
variations of ozone over the surroundings of each megacity as well as its
daily variability. We show here that the large lower tropospheric ozone
amounts (0–6 km partial columns) observed with IASI are mainly downwind the
highest populated areas in each region, thus possibly suggesting the
anthropogenic origin of the large ozone amounts observed. Finally, an
analysis of the mean ozone profiles over each region – for selected days
with high ozone events – in association with the analysis of the
meteorological situation shows that the high ozone amounts observed during
winter are likely related to descents of ozone-rich air from the
stratosphere, whereas in spring and summer the tropospheric ozone is likely
enhanced by photochemical production in polluted areas and/or in air masses
from fire plumes. |
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