A simulation of the OMEGA/Mars Express observations: Analysis of the atmospheric contribution

R. Melchiorri (1) , P. Drossart (1) , T. Fouchet (1) , B. Bézard (1) , F. Forget (2) , Aline Gendrin (3) , J.-P. Bibring (4) , N. Manaud (4) , The Omega Team , Michel Berthe (4) , Y. Langevin (4) , O. Forni (4) , B. Gondet (4) , F. Poulet (4) , G. Poulleau (4) , Alain Soufflot (4) , Nicolas Mangold (4) , G. Bonello (4) , M. Combes (1) , T. Encrenaz (1) , S. Erard (1) , G. Bellucci (5) , F. Altieri (5) , V. Formisano (5) , S. Fonti (6) , F. Capaccioni (7) , P. Cerroni (7) , A. Coradini (7) , Volodia Kottsov (8) , N. Ignatiev (8) , L. V. Moroz (8) , D. Titov (8) , Ludmilla Zasova (8) , P. Pinet (9) , Bernard Schmitt (10) , Christophe Sotin (11) , Ernst Hauber (12) , Harald Hoffmann (12) , R. Jaumann (13) , Uwe Keller , Raymond Arvidson (3) , John F. Mustard (14) , Tom Duxbury (14)

1 LESIA - Laboratoire d'études spatiales et d'instrumentation en astrophysique
2 LMD - Laboratoire de Météorologie Dynamique (UMR 8539)
3 Department of Geological Sciences [Providence]
4 IAS - Institut d'astrophysique spatiale
5 IFSI - Istituto di Fisica dello Spazio Interplanetario
6 Dipartimento di Fisica
7 IASF-Roma - Istituto di Astrofisica Spaziale e Fisica cosmica - Roma
8 IKI - Space Research Institute of the Russian Academy of Sciences
9 UMS 831 - Services communs OMP
10 LPG - Laboratoire de Planétologie de Grenoble
11 LPG - Laboratoire de Planétologie et Géodynamique [UMR 6112]
12 DLR - German Aerospace Center
13 MPS - Max-Planck-Institut für Sonnensystemforschung
14 JPL - Jet Propulsion Laboratory

Spectral images of Mars obtained by the Mars Express/OMEGA experiment in the near infrared are the result of a complex combination of atmospheric, aerosol and ground features. Retrieving the atmospheric information from the data is important, not only to decorrelate mineralogical against atmospheric features, but also to retrieve the atmospheric variability. Once the illumination conditions have been taken into account, the main source of variation on the CO2 absorption is due to the altitude of the surface, which governs atmospheric pressure variation by more than an order of magnitude between the summit of Olympus Mons down to the bottom of Valles Marineris. In this article we present a simplified atmospheric spectral model without scattering, specially developed for the OMEGA observations, which is used to retrieve the local topography through the analysis of the View the MathML source CO2 band. OMEGA atmospheric observations increase the horizontal resolution compared to MOLA altimetry measurements, and therefore complement the mineralogical studies from the same instrument. Finally, residual variations of the pressure can be related to atmospheric structure variation.

Keywords: Line-by-line; Image-spectroscopy; Altimetry; Mars; Mars Express; OMEGA; Planetary atmosphere; Topography

Domains: Sciences of the Universe [physics]; Astrophysics [astro-ph]

R. Melchiorri, P. Drossart, T. Fouchet, B. Bézard, F. Forget, et al.. A simulation of the OMEGA/Mars Express observations: Analysis of the atmospheric contribution. Planetary and Space Science, 2006, 54 (8), pp.774-783. ⟨10.1016/j.pss.2006.04.014⟩. ⟨insu-00364140⟩