Magnetospheric Electrons as a Source of Titan's Ionosphere: Model Comparisons with Cassini Data

HR: 11:30h
AN: P52A-05 [Abstracts]
TI: Magnetospheric Electrons as a Source of Titan's Ionosphere: Model Comparisons with Cassini Data
AU: * Cravens, T E
EM: cravens@ku.edu
AF: University of Kansas, Department of Physics and Astronomy, University of Kansas, Lawrence, KS 66045 United States
AU: Robertson, I P
EM: robertin@ku.edu
AF: University of Kansas, Department of Physics and Astronomy, University of Kansas, Lawrence, KS 66045 United States
AU: Keller, C N
EM: charles_n_keller@cornerstone.edu
AF: Cornerstone University, Cornerstone University, Dept. of Physical Sciences, Cornerstone Univ., Grand Rapids, MI 49505 United States
AU: Waite, J H
EM: hunterw@umich.edu
AF: University of Michigan, Dept. of Atmospheric, Oceanic, and Space Sciences, 2455 Hayward, University of Michigan, Ann Arbor, MI 48109-2143 United States
AU: Kasprzak, W T
EM: wayne.kascprzak@gsfc.nasa.gov
AF: NASA Goddard Space Flight Center, NASA Goddard Space Flight Center, Greenbelt, MD 20771 United States
AU: Niemann, H B
EM: Hasso.Niemann@gsfc.nasa.gov
AF: NASA Goddard Space Flight Center, NASA Goddard Space Flight Center, Greenbelt, MD 20771 United States
AU: Yelle, R V
EM: yelle@lpl.arizona.edu
AF: University of Arizona, Lunar and Planetary Laboratory, University of Arizona, 1629 E. University Blvd, Tucson, AZ 85721-0092 United States
AU: Luhmann, J G
EM: jgluhman@sunspot.ssl.berkeley.edu
AF: University of California Berkeley, Space Sciences Laboratory, University of California, Berkeley, CA 94720 United States
AU: Ledvina, S
EM: ledvina@ssl.berkeley.edu
AF: University of California Berkeley, Space Sciences Laboratory, University of California, Berkeley, CA 94720 United States
AU: McNutt, R L
EM: ralph_mcnutt@jhuapl.edu
AF: Applied Physics Laboratory, Johns Hopkins University, Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723 United States
AU: Ip, W
EM: wingip@astro.ncu.edu.tw
AF: National Central University, National Central University Taiwan, Chung-Li, 32054 Taiwan
AU: De La Haye, V
EM: vdelah@engin.umich.edu
AF: University of Michigan, Dept. of Atmospheric, Oceanic, and Space Sciences, 2455 Hayward, University of Michigan, Ann Arbor, MI 48109-2143 United States
AU: M〕ler-Wordag, I
EM: i.Muellerwodarg@imperial.ac.uk
AF: Imperial College, Space and Atmospheric Physics Group, Imperial College, London, SW7 2BW United Kingdom
AU: Coates, A J
EM: ajc@mssl.ucl.ac.uk
AF: University College London, Mullard Space Science Laboratory Holmbury St Mary, Dorking, Surrey RH5 6NT, Holmbury St Mary, RH5 6NT United Kingdom
AB: The Cassini Ion and Neutral Mass Spectrometer (INMS) onboard the Cassini Orbiter measured the neutral composition and structure of the upper atmosphere during 3 encounters. The INMS measured the ionospheric composition only on the outbound leg of the T5 pass, when the spacecraft was on the nightside. Possible ionization sources for this nightside ionosphere include transport from the dayside, or (more likely) electron impact ionization associated with precipitation of magnetospheric electrons. We use a model of Titan's ionosphere, which includes ion chemistry, suprathermal electron transport, and electron energetics to investigate how the ionosphere responds to magnetospheric inputs. In particular, model results seem to suggest that magnetospheric electrons with energies between about 25 eV and 800 eV are needed to explain the ion density profiles measured by the INMS. The model is also used to interpret the ion composition seen by the INMS and to test the ion chemistry scheme used.
DE: 2455 Particle precipitation
DE: 5408 Aurorae and airglow
DE: 5435 Ionospheres (2459)
DE: 5443 Magnetospheres (2756)
DE: 6025 Interactions with solar wind plasma and fields
SC: Planetary Sciences [P]
MN: Fall Meeting 2005