HR: 1340h
AN: P33B-1293    [Abstracts]
TI: Flux-rope Structure in the Ionospheres of Venus and Titan
AU: * Wei, H Y
EM: hwei@igpp.ucla.edu
AF: Institute of Geophysics and Planetary Physics, 3846 Slichter Hall, University of California, Los Angeles, CA 90095-1567, United States
AU: Russell, C T
EM: ctrussel@igpp.ucla.edu
AF: Institute of Geophysics and Planetary Physics, 3846 Slichter Hall, University of California, Los Angeles, CA 90095-1567, United States
AU: Zhang, T L
EM: Tielong.Zhang@oeaw.ac.at
AF: Space Research Institute, Space Research Institute, Graz, A-8042, Austria
AU: Dougherty, M K
EM: m.dougherty@ic.ac.uk
AF: The Blackett Laboratory, Dept. of Physics, Imperial College, London, SW7 2BZ, United Kingdom
AU: Luhmann, J G
EM: jgluhman@ssl.berkeley.edu
AF: Space Sciences Laboratory, University of California, Berkeley, San Jose, CA 94720, United States
AU: Wahlund, J -
EM: jwe@irfu.se
AF: Swedish Institute of Space Physics, Uppsala Division, Box 537, Uppsala, SE-751 21, Sweden
AU: Delva, M
EM: Magda.Delva@oeaw.ac.at
AF: Space Research Institute, Space Research Institute, Graz, A-8042, Austria
AU: Ma, Y J
EM: yingjuan@igpp.ucla.edu
AF: Institute of Geophysics and Planetary Physics, 3846 Slichter Hall, University of California, Los Angeles, CA 90095-1567, United States
AB: Magnetic flux ropes, which have the structure of twisted flux tubes, are created in the ionosphere of Venus by its interaction with the solar wind and in that of Titan during it interacting with the flowing magnetized plasma corotating with Saturn. At solar maximum, the Venus ionosphere was found to be generally field free by the PVO eccentric orbiter, and flux ropes are frequently observed in the field-free region below the ionopause. During solar minimum, Venus Express detects a largely magnetized ionosphere, and flux ropes are observed both in the lower ionosphere with no background field and near the ionopause with some background field. The latter appears to be in the early stage of flux-rope formation. Similarly, the repeated low-altitude passes of Cassini through the Titan atmosphere reveal a "strongly" magnetized ionosphere and twisted magnetic field lines are observed which resemble the flux rope in Venus ionosphere during formation. This paper studies the flux-rope structures in Venus ionosphere during solar maximum and solar minimum and in Titan's ionosphere to understand the formation of flux ropes and what controls the orientation and helicity of a flux rope.
DE: 0654 Plasmas
DE: 2400 IONOSPHERE (6929)
DE: 2780 Solar wind interactions with unmagnetized bodies
DE: 6281 Titan
DE: 6295 Venus
SC: Planetary Sciences [P]
MN: 2007 Fall Meeting