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| Titel |
Modeling and observation of the CO Cameron bands in the upper atmosphere of Mars |
| VerfasserIn |
G. Gronoff, C. Simon Wedlund, C. J. Mertens, M. Barthélémy, R. Lillis |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250069952
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| Zusammenfassung |
| The CO(a3Π- X1Σ+) emission bands, the Cameron bands, have been observed in the
atmospheres of Mars and Venus for a long time. They are mainly produced by dissociation of
the CO2 molecules by photon and electron impacts.
The SPICAM spectrometer onboard Mars express was able to detect these bands by limb
observation of the Martian UV airglow. We present here the comparison of these observations
with the simulations of the Aeroplanets model (a photon and electron transport model,
capable of computing the excited state species production and the resulting emissions; but
also a forward model, able to retrieve the atmospheric parameters through model-simulation
comparisons).
By carefully checking the uncertainties in the Aeroplanets model, we were firstly able to
reassess the discrepancy between the different airglow models and the observations (as seen
in Simon et al. 2009, Cox et al. 2010, Jain and Bhardwaj 2011). An examination of the
sources of uncertainties showed that the division by three of the Cameron band production by
electron impact on CO2 cross section would solve the problem. This division by three is
supported by laboratory reassessment of the Cameron band transition (Gilijamse et al
2007).
The improvement of the accuracy of the Cameron bands simulations gives perspectives
on their use to derive key parameters of the neutral atmosphere such as the exospheric
temperature, the scale height of CO2, and their dependence on the solar longitude
Ls. |
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