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| Titel |
Mesospheric NO2 production due to relativistic electron precipitation from 2007 till 2011 |
| VerfasserIn |
Felix Friederich, Miriam Sinnhuber, Bernd Funke, Thomas von Clarmann, Gabriele Stiller, Johannes Orphal |
| 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 |
250076165
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| Zusammenfassung |
| Electrons of the radiation belts and the aurora can precipitate into the Earth’s atmosphere.
Depending on their energy they intrude into different altitudes and can excitate, ionize, and
dissociate molecular nitrogen. Subsequent (ion-)chemical reactions result in an
effective NOx-production (NOx=NO+NO2). NOx is produced mostly by auroral
electrons in the thermosphere at ca. 110 km altitude. But relativistic electrons from the
radiation belts can also reach the stratosphere. However, in the stratosphere and lower
mesosphere, no direct NOx-production due to electron precipitation has been detected
yet.
We use NO2 observations from the Michelson Interferometer for Passive Atmospheric
Sounding (MIPAS) on Envisat in the altitude range from 40 km to 60 km in order to search
for direct NOx-production. We show that the AP index correlates with the nighttime NO2
abundance between 44 km and 54 km altitude at 65±5°N geomagnetic latitude. At these
altitudes the NO2 ratio of nighttime NOx is between 80 % and 100 %. Because of
the correlation between AP index and nighttime NO2, we conclude, that there is
direct NOx-production caused by relativistic electrons about 0.5 ppb at the most. |
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