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| Titel |
Summertime tropospheric-ozone variability over the Mediterranean basin observed with IASI |
| VerfasserIn |
C. Doche, G. Dufour, G. Foret, M. Eremenko, J. Cuesta, M. Beekmann, P. Kalabokas |
| 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 ; 14, no. 19 ; Nr. 14, no. 19 (2014-10-09), S.10589-10600 |
| Datensatznummer |
250119085
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| Publikation (Nr.) |
 copernicus.org/acp-14-10589-2014.pdf |
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| Zusammenfassung |
| The Mediterranean basin is one of the most sensitive regions in the world
regarding climate change and air quality. This is partly due to the singular
dynamical situation of the Mediterranean basin that leads to tropospheric-ozone concentrations that are among the
highest over the Northern Hemisphere. Six
years of summertime tropospheric ozone observed by the Infrared Atmospheric
Sounding Interferometer (IASI) instrument from 2007 to 2012 have been
analysed to document the variability of ozone over this region. The satellite
observations have been examined together with meteorological analyses (from
ECMWF) to understand the processes driving this variability. Our work
confirmed the presence of a steep west–east ozone gradient in the lower
troposphere with the highest concentrations observed over the eastern part of
the Mediterranean basin. This gradient is mainly explained by diabatic
convection over the Persian Gulf during the Indian monsoon season, which
induces an important subsidence of ozone-rich air masses from the upper to
the lower troposphere over the central and the eastern Mediterranean basin.
IASI observations of ozone concentrations at a 3 km height show a clear
summertime maximum in July that is well correlated to the maximum of downward
transport of ozone-rich air masses from the upper troposphere. Even if this
feature is robust over the six analysed years, we have also investigated
monthly ozone anomalies – one positive (June 2008) and one negative (June and
July 2009) – using daily IASI observations. We show that the relative position
and the strength of the meteorological systems (Azores anticyclone and Middle
Eastern depression) present over the Mediterranean are key factors in
explaining both the variability and the anomalies of ozone in the lower troposphere in
this region. |
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