HR: 0800h
AN: P11A-0245    [Abstracts]
TI: Ionopause Features of Mars as observed by the Radio Science Experiment MaRS on Mars Express
AU: Peter, K
EM: peter@geo.uni-koeln.de
AF: Rheinisches Institut für Umweltforschung, Abteilung Planetenforschung, Universität zu Köln, Aachener Str. 209, Cologne, 50931, Germany
AU: * Pätzold, M
EM: paetzold@geo.uni-koeln.de
AF: Rheinisches Institut für Umweltforschung, Abteilung Planetenforschung, Universität zu Köln, Aachener Str. 209, Cologne, 50931, Germany
AU: Häusler, B
EM: Bernd.Haeusler@unibw-muenchen.de
AF: Institut für Raumfahrttechnik, Universität der Bundeswehr München, Werner- Heisenberg-Weg 39, Neubiberg, 85577, Germany
AU: Tellmann, S A
EM: tellmann@geo.uni-koeln.de
AF: Rheinisches Institut für Umweltforschung, Abteilung Planetenforschung, Universität zu Köln, Aachener Str. 209, Cologne, 50931, Germany
AU: Tyler, G L
EM: len.tyler@stanford.edu
AF: Department of Electrical Engineering, Stanford University, Serra Mall, Stanford, CA 94305, United States
AB: The ionopause of a planet is defined as the boundary between the ionosphere and the solar wind regime. It was first described for Venus when a sharp decrease in electron density towards very small values was found at certain altitudes. So far, the ionopause at Mars has not been well observed. One reason is that the noise of the Viking profiles was relatively high and did not drop below 500 el/cc. The MGS data base is inconclusive concerning the ionopause. The highly elliptical orbit of Mars Express allows us to investigate the electron density of Mars up to an altitude of about 1500 km. We want to define the ionopause feature at Mars as an electron density gradient starting well above the topside ionospheric main peak, tending to decrease the electron density towards noisy values around zero. The Radio Science Experiment MaRS on Mars Express sounded the Martian atmosphere and ionosphere during four occultation seasons starting from April 2004. So far, more than 400 vertical profiles of the ionospheric electron density could be derived covering both hemispheres and almost all local times. This presentation will show the high variability of the ionopause structures of Mars.
DE: 2459 Planetary ionospheres (5435, 5729, 6026)
SC: Planetary Sciences [P]
MN: 2007 Fall Meeting