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| Titel |
Unusually strong nitric oxide descent in the Arctic middle atmosphere in early 2013 as observed by Odin/SMR |
| VerfasserIn |
K. Pérot, J. Urban, D. P. Murtagh |
| 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. 15 ; Nr. 14, no. 15 (2014-08-12), S.8009-8015 |
| Datensatznummer |
250118937
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| Publikation (Nr.) |
 copernicus.org/acp-14-8009-2014.pdf |
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| Zusammenfassung |
| The middle atmosphere was affected by an exceptionally strong midwinter
stratospheric sudden warming (SSW) during the Arctic winter 2012/2013. These
unusual meteorological conditions led to a breakdown of the polar vortex,
followed by the reformation of a strong upper stratospheric vortex associated
with particularly efficient descent of air. Measurements by the
submillimetre radiometer (SMR), on board the Odin satellite, show that very
large amounts of nitric oxide (NO), produced by energetic particle
precipitation (EPP) in the mesosphere/lower thermosphere (MLT), could thus
enter the polar stratosphere in early 2013. The mechanism referring to the
downward transport of EPP-generated NOx during winter is generally
called the EPP indirect effect. SMR observed up to 20 times more NO in the
upper stratosphere than the average NO measured at the same latitude,
pressure and time during three previous winters where no mixing between
mesospheric and stratospheric air was noticeable. This event turned out to be
the strongest in the aeronomy-only period of SMR (2007–present). Our study is
based on a comparison with the Arctic winter 2008/2009, when a similar
situation was observed. This outstanding situation is the result of the
combination of a relatively high geomagnetic activity and an unusually
high dynamical activity, which makes this case a prime example to study the
EPP impacts on the atmospheric composition. |
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