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| Titel |
Discovery and characterization of an ozone layer in Venus' atmosphere |
| VerfasserIn |
Franck Montmessin, Jean-Loup Bertaux, Franck Lefèvre, Emmanuel Marcq, Denis Belyaev, Jean-Claude Gérard, Oleg Korablev, Anna Fedorova, Vincent Sarago, Ann-Carine Vandaele |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250052711
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| Zusammenfassung |
| The SPICAV instrument onboard the Venus Express spacecraft is a multi-channel suite
covering the far ultraviolet to the mid-infrared. In this presentation, we will focus on the
results obtained by the UV channel during stellar occultations observations. Stellar
occultation technique possesses well-known advantages: self-calibration, low sensitivity to
instrument aging, simple laws of radiative transfer. In addition, occultation with stars permit
to cover a broad range of latitudes at any given season and they provide optimal geometrical
registration. Since Venus Express orbit insertion, several hundreds of occultations have been
performed by SPICAV, yielding profiles of atmospheric constituents between 80 and
140 km. In the SPICAV UV range, CO2Â possesses a broad signature shortward
of 200 nm which allows one to retrieve CO2 concentration and subsequently to
deduce atmospheric pressure and temperature profiles in the upper mesosphere and in
the thermosphere. The Venusian thermosphere shows excessive variability, with
the equivalent of more than three scale heights change in density in less than a
few days. No other spectral signature besides that of CO2Â and haze particles was
expected to appear in SPICAV ultraviolet spectra at this altitude range but a consistent
search was undertaken, revealing the presence of ozone at 100 km ( |
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