HR: 09:15h
AN: P31D-06    [Abstracts]
TI: OMEGA Mars Express: Water Vapour Daily Variability on the South Pole
AU: * Melchiorri, R
EM: riccardo.melchiorri@obspm.fr
AF: LESIA OBSPM, 5, place Jules Janssen, Meudon, 92195, France
AU: Encrenaz, T
EM: therese.encrenaz@obspm.fr
AF: LESIA OBSPM, 5, place Jules Janssen, Meudon, 92195, France
AU: Drossart, P
EM: pierre.drossart@obspm.fr
AF: LESIA OBSPM, 5, place Jules Janssen, Meudon, 92195, France
AU: fouchet, t
EM: thierry.fouchet@obspm.fr
AF: LESIA OBSPM, 5, place Jules Janssen, Meudon, 92195, France
AU: forget, f
EM: forget@lmd.jussieu.fr
AF: LMD Paris6, 4, place Jussieu, Paris, 75005, France
AU: Titov, D
EM: titov@mps.mpg.de
AF: MAX Planck, Max-Planck-Str. 2 Katlenburg-, Lindau, 37191, Germany
AU: maltagliati, l
EM: maltagliati@mps.mpg.de
AF: MAX Planck, Max-Planck-Str. 2 Katlenburg-, Lindau, 37191, Germany
AU: Altieri, F
EM: francesca.altieri@iasf-roma.inaf.it
AF: INAF, via del fosso del Cavaliere 100, Roma, 00100, Italy
AU: Bellucci, G
EM: giancarlo.bellucci@iasf-roma.inaf.it
AF: INAF, via del fosso del Cavaliere 100, Roma, 00100, Italy
AU: Langevin, Y
EM: yves.langevin@ias.u-psud.fr
AF: IAS, Orsay, Université Paris XII, Orsay, 91405, France
AU: Bibring, j
EM: jean-pierre.bibring@ias.u-psud.fr
AF: IAS, Orsay, Université Paris XII, Orsay, 91405, France
AB: We report on an analysis of the Water vapour on the South Pole for the period LS=250°-270°. This period and region is characterized by a temperature and pressure that vary around the saturation point of the water. We observe an enhancement of the water vapour during the day, going from 5 - 10 ppt-µm in the morning side to 15 - 18 ppt-µm in the evening. This may suggest the following scenario: in the morning the water ice is condensed on/under the surface; as soon as it is illuminated by the Sun, the temperature difference makes it sublimate; the production continues up to the evening with a "quasi" constant slope (0.5 ppt-µm/hour); the evening observations are characterized by a homogeneity of the water vapour which could be explained by a mixing of the atmosphere which redistributes the sublimated morning water vapour in a few hours. The lack of data in the late evening does not allow to argue on a possible condensation during the night and even if no water ice is detected by OMEGA on the ground, it is the most plausible explanation to the low value of water vapour content in the early morning.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0325 Evolution of the atmosphere (1610, 8125)
DE: 0343 Planetary atmospheres (5210, 5405, 5704)
SC: Planetary Sciences [P]
MN: 2007 Fall Meeting