Sublimation of the Martian CO2 seasonal South Polar Cap.

• Published in: Planetary and Space Science
• Main Authors: Schmidt, F., Schmidt, B., Doute, S., Forget, F., Jian, J.J., Martin, P., Langevin, Y., Bibring, J.P.
• Other Authors: Interactions et dynamique des environnements de surface (IDES), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), European Space Astronomy Centre (ESAC), European Space Agency (ESA), Université Joseph Fourier - Grenoble 1 (UJF), Laboratoire de Planétologie de Grenoble (LPG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École des Ponts ParisTech (ENPC)-École polytechnique (X)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Institute of Astronomy Taiwan (IANCU), National Central University Taiwan (NCU), Institut d'astrophysique spatiale (IAS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2010
• Subjects: [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology; South Pole; South pole
• Online Access: https://hal.archives-ouvertes.fr/hal-00530185; https://doi.org/10.1016/j.pss.2010.03.018

International audience The polar condensation/sublimation of CO2, that involve about one fourth of the atmosphere mass,is the major Martian climatic cycle.Early observations in visible and thermal infrared have shown that the sublimation of the Seasonal South Polar Cap (SSPC) is not symmetric around the geographic South Pole. Here we use observations by OMEGA/Mars Express in the near-infrared to detect un ambiguously the presence of CO2 at the surface, and to estimate albedo. Second,we estimate the sublimation of CO2 released in the atmosphere and show that there is a two-stepprocess.FromLs¼180° to 220°, the sublimation is nearly symmetric with a slight advantage for the cryptic region.After Ls¼220° the anti-cryptic region sublimation is stronger. Those two phases are not balanced such that there is 22% +- 9 more mass the anti-cryptic region,arguing for more snow precipitation. We compare those results with the MOLA height measurements. Finally we discus simplications for the Martian atmosphere about general circulation and gas tracers,e.g.Ar.