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| Titel |
On the connection between stratospheric water vapour changes and widespread severe denitrification in the Arctic |
| VerfasserIn |
Farahnaz Khosrawi, Jo Urban, Stefan Lossow, Gabi Stiller, Donal Murtagh |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250075322
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| Zusammenfassung |
| Water vapour is one of the most important greenhouse gases and plays a key role in the
chemistry of the upper troposphere and lower stratosphere (UT/LS). Any changes in
atmospheric water vapour bring important implications for the global climate. Long-term
ground-based and satellite measurements indicate an increase of stratospheric water vapour
abundance by an average of 1Â ppmv during the last 30Â years (1980-2010). Increases in
stratospheric water vapour cool the stratosphere but warm the troposphere. Both the cooling
of the stratosphere and the increase in water vapour enhance the potential for the formation of
polar stratospheric clouds. More than a decade ago it already was suggested that a cooling of
stratospheric temperatures by 1Â K or an increase of 1Â ppmv of stratospheric water vapor
could promote denitrification, the permanent removal of nitrogen species from the
stratosphere by solid polar stratospheric cloud particles. In fact, during the two recent
Arctic winter 2009/2010 and 2010/2011 the strongest denitrification in the recent
decade was measured by Odin/SMR. In the latter winter denitrification lead also to
severe ozone depletion with similar extensions as the Antarctic “ozone hole”. In
this study, the correlation between observed water vapour trends and the recent
temperature evolution in the Arctic together with trace gas measurements and PSC
observations are considered to investigate a possible connection between the increase in
stratospheric water vapour and polar stratospheric cloud formation/denitrification. |
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