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| Titel |
Escape of Mars’ CO2 atmosphere by suprathermal atoms during the past 4 Gyrs |
| VerfasserIn |
Ute Amerstorfer, Hannes Gröller, Herbert Lichtenegger, Helmut Lammer, Feng Tian |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250134038
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| Publikation (Nr.) |
 EGU/EGU2016-14719.pdf |
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| Zusammenfassung |
| The escape of atmospheric particles plays a crucial role in the evolution of the atmosphere of
Mars. Especially, the escape of oxygen and carbon is thought to have influenced its amount of
CO2.
With a Monte-Carlo model we investigate the escape of hot oxygen and carbon from the
martian atmosphere for three points in time in its history corresponding to 3, 10, and 20 times
the present EUV level. We study and discuss different possible sources of hot oxygen and
carbon atoms in the thermosphere and their changing importance with the EUV
flux. We find that the escape due to photodissociation increases with increasing
EUV level, as is a commonly assumed opinion. However, for the escape via other
reactions, e.g. dissociative recombination, this is only true until the EUV level
reaches 10 times the present EUV flux, but then the rates start to decrease. Our
results thus suggest that some escape mechanisms related to the loss of CO2 are
less important than previously thought for atmospheres exposed to higher EUV
radiation.
This work receives funding from the Austrian Science Fund (FWF): P 24247-N16. |
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