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| Titel |
A climatology of surface ozone in the extra tropics: cluster analysis of observations and model results |
| VerfasserIn |
O. A. Tarasova, C. A. M. Brenninkmeijer, P. Jöckel, A. M. Zvyagintsev, G. I. Kuznetsov |
| 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 ; 7, no. 24 ; Nr. 7, no. 24 (2007-12-12), S.6099-6117 |
| Datensatznummer |
250005277
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| Publikation (Nr.) |
 copernicus.org/acp-7-6099-2007.pdf |
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| Zusammenfassung |
| Important aspects of the seasonal variations of surface ozone are discussed.
The underlying analysis is based on the long-term (1990–2004) ozone records
of the Co-operative Programme for Monitoring and Evaluation of the
Long-range Transmission of Air Pollutants in Europe (EMEP) and the World
Data Centre of Greenhouse Gases, which provide data mostly for the Northern
Hemisphere. Seasonal variations are pronounced at most of the 114 locations
at all times of the day. A seasonal-diurnal variations classification using
hierarchical agglomeration clustering reveals 6 distinct clusters: clean
background, rural, semi-polluted non-elevated, semi-polluted semi-elevated,
elevated and polar/remote marine. For the "clean background" cluster the
seasonal maximum is observed in March-April, both for night and day. For
those sites with a double maximum or a wide spring-summer maximum, the
spring maximum appears both for day and night, while the summer maximum is
more pronounced for daytime and hence can be attributed to photochemical
processes. The spring maximum is more likely caused by dynamical/transport
processes than by photochemistry as it is observed in spring for all times
of the day. We compare the identified clusters with corresponding data from
the 3-D atmospheric chemistry general circulation model ECHAM5/MESSy1
covering the period of 1998–2005. For the model output as for the
measurements 6 clusters are considered. The simulation shows at most of the
sites a spring seasonal maximum or a broad spring-summer maximum (with
higher summer mixing ratios). For southern hemispheric and polar remote
locations the seasonal maximum in the simulation is shifted to spring, while
the absolute mixing ratios are in good agreement with the measurements. The
seasonality in the model cluster covering background locations is
characterized by a pronounced spring (April–May) maximum. For the model
clusters which cover rural and semi-polluted sites the role of the
photochemical production/destruction seems to be overestimated. Taking into
consideration the differences in the data sampling procedure, the comparison
demonstrates the ability of the model to reproduce the main regimes of
surface ozone variations quite well. |
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