A layer of ozone detected in the nightside upper atmosphere of Venus

Franck Montmessin (1) , Jean-Loup Bertaux (1) , Franck Lefèvre (1) , Emmanuel Marcq (1) , Denis Belyaev (1, 2) , J.-C. Gérard (3) , O. Korablev (2) , Anna Fedorova (2) , Vincent Sarago (1) , A. C. Vandaele (4)

1 PLANETO - LATMOS
2 IKI - Space Research Institute of the Russian Academy of Sciences
3 LPAP - Laboratoire de Physique Atmosphérique et Planétaire
4 BIRA-IASB - Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique

To date, ozone has only been identified in the atmospheres of Earth and Mars. This study reports the first detection of ozone in the atmosphere of Venus by the SPICAV ultraviolet instrument onboard the Venus Express spacecraft. Venusian ozone is characterized by a vertically confined and horizontally variable layer residing in the thermosphere at a mean altitude of 100 km, with local concentrations of the order of 107-108 molecules.cm-3. The observed ozone concentrations are consistent with values expected for a chlorine-catalyzed destruction scheme, indicating that the key chemical reactions operating in Earth's upper stratosphere may also operate on Venus.

Mots clés: Atmospheric Chemistry; Atmospheric composition; Occultations; Venus; Atmosphere; Spectroscopy

Domaines: Planétologie et astrophysique de la terre [astro-ph.EP]; Planétologie et astrophysique de la terre [astro-ph.EP]

Franck Montmessin, Jean-Loup Bertaux, Franck Lefèvre, Emmanuel Marcq, Denis Belyaev, et al.. A layer of ozone detected in the nightside upper atmosphere of Venus. Icarus, 2011, 216 (1), pp.82-85. ⟨10.1016/j.icarus.2011.08.010⟩. ⟨hal-00618964⟩