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| Titel |
Hydroxyl nightglow on Venus observed by VIRTIS on Venus-Express |
| VerfasserIn |
A. Migliorini, G. Piccioni, P. Drossart, A. Cardesín Moinelo, The VIRTIS-Venus Express Team |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250029482
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| Zusammenfassung |
| Hydroxyl has been recently observed for the first time in the Venusian atmosphere with the
VIRTIS spectrometer on board the Venus-Express spacecraft. The transitions (1-0) around
2.81 microns and (2-0) around 1.46 microns have been detected. The intensity of the two
emissions are respectively about 55 and 480 times less intense than the (0-0) oxygen
transition (Piccioni et al, A&A, 2008). The possible chemical reactions which can produce
hydroxyl on Venus involve O3 and HO2, with the former being the most probable, and
hence OH can be used to indirectly infer the ozone distribution on Venus. VIRTIS
data in limb mode observation were analyzed to derive the mean distribution of
hydroxyl in the night side of Venus and the results are presented here. The typical peak
altitude of the two emissions is set at 95-96 km in limb view, a few km lower than the
oxygen emission at 1.27 um due to the transition (0-0). The peak altitude of the
latter typically occurs at 97-98 km height. The OH full width at half maximum is
in average about 7 km, and sometimes higher. The mean map of (1-0) hydroxyl
distribution around 2.81 microns shows a maximum of emission of about 130 kR
near the anti-solar point at about 1h local time. The study of the (2-0) hydroxyl
distribution at around 1.46 microns results more difficult due to its weak intensity. |
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