Geographic distribution of zonal wind and UV albedo at cloud top level from VMC camera on Venus Express: Influence of Venus topography through stationary gravity waves vertical propagation

Jean-Loup Bertaux (1) , Igor V. Khatunstsev (2, 3) , Alain Hauchecorne (4) , Wojciech J. Markiewicz (5) , Emmanuel Marcq (6) , Sébastien Lebonnois (7) , Marina V. Patsaeva (2) , Alexander V. Turin (2)

1 HELIOS - LATMOS
2 MIPT - Moscow Institute of Physics and Technology [Moscow]
3 IKI - Space Research Institute of the Russian Academy of Sciences
4 STRATO - LATMOS
5 MPS - Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research
6 PLANETO - LATMOS
7 LMD - Laboratoire de Météorologie Dynamique (UMR 8539)

Based on the analysis of UV images (at 365 nm) of Venus cloud top collected with VMC camera on board Venus Express [4,5], it is found that the zonal wind speed south of the equator (from 5°S to 15°s) shows a conspicuous variation with geographic longitude of Venus, correlated with underlying relief of Aphrodite Terra. We interpret this pattern as the result of stationary gravity waves produced at ground level by the up lift of air when the horizontal wind encounters a mountain slope. The cloud albedo map at 365 nm varies also in longitude and latitude, perhaps the result of increased vertical mixing associated to wave breaking, and decreased abundance of the UV absorber which makes the contrast in images.

Domaines: Planétologie et astrophysique de la terre [astro-ph.EP]; Instrumentation et méthodes pour l'astrophysique [astro-ph.IM]; Astrophysique stellaire et solaire [astro-ph.SR]

Jean-Loup Bertaux, Igor V. Khatunstsev, Alain Hauchecorne, Wojciech J. Markiewicz, Emmanuel Marcq, et al.. Geographic distribution of zonal wind and UV albedo at cloud top level from VMC camera on Venus Express: Influence of Venus topography through stationary gravity waves vertical propagation. European Planetary Science Congress 2015, Sep 2015, Nantes, France. pp.EPSC2015-87. ⟨insu-01213709⟩