HR: 1340h
AN: P33C-0257    [Abstracts]
TI: Heating of the Upper Atmosphere and the Expansion of the Corona of Titan
AU: * Michael, M
EM: mm2eq@virginia.edu
AF: Materials Science and Engineering, University of Virginia, Charlottesville, VA 22904 United States
AU: Johnson, R E
EM: rej@virginia.edu
AF: Materials Science and Engineering, University of Virginia, Charlottesville, VA 22904 United States
AU: Shematovich, V I
EM: shematov@inasan.rssi.ru
AF: Institute of Astronomy, RAS, Moscow, 119017 Russian Federation
AU: La Haye, V D
EM: vdelah@umich.edu
AF: University of Michigan, University of Michigan, Ann Arbor, MI 48109 United States
AU: Waite, H
EM: hunterw@umich.edu
AF: University of Michigan, University of Michigan, Ann Arbor, MI 48109 United States
AU: Wong, M C
EM: mauwong@jpl.nasa.gov
AF: Jet Propulsion Laboratory, Jet Propulsion Laboratory, Pasadena, CA 91109 United States
AU: Sittler, E C
EM: Edward.C.Sittler@nasa.gov
AF: Goddard Space Flight Center, NASA, Greenbelt, MD 20771 United States
AU: Ledvina, S
EM: ledvina@ssl.berkeley.edu
AF: Space Science Laboratory, University of California, Berkeley, CA 94720 United States
AU: Luhmann, J G
EM: jgluhman@ssl.berkeley.edu
AF: Space Science Laboratory, University of California, Berkeley, CA 94720 United States
AU: Leblanc, F
EM: francois.leblanc@aerov.jussieu.fr
AF: Service d'Aeronomie, CNRS, verrieres, 91371 France
AB: The atmosphere of Titan and its plasma environment are of much interest due to the recent observations by the Cassini spacecraft. It is well established that the upper atmosphere of Titan is continuously bombarded by pick-up ions and deflected ambient magnetospheric ions (Shematovich et al 2003). The deposition of energy, escape of atoms and molecules, and heating of the upper atmosphere of Titan are studied using a Direct Simulation Monte Carlo method (Michael et al 2005). It is found that the globally averaged flux of deflected magnetospheric ions and pick-up ions deposit more energy in the exobase region of Titan than solar radiation. The energy deposition in this region determines the non-thermal corona, the atmospheric loss, and the production of a neutral torus. It is found that the inclusion of the molecular pickup ions is critical to accurately determining the amount of energy deposited close to the exobase (Michael and Johnson 2005). Depending on the nature of the local interaction with the magnetosphere, the plasma flow through the exobase region and heating of the exobase region can increase the content of the corona (Michael and Johnson 2005). We compare the model results with the observational data of a number of instruments onboard Cassini spacecraft. References Michael, M., Johnson, R.E., Leblanc, F., Liu, M., Luhmann, J.G., Shematovich, V. I., Ejection of Nitrogen from Titan's atmosphere by magnetospheric ions and pickup Ions. Icarus, 175, 263-267, 2005. Michael, M., Johnson, R.E., Energy deposition of pickup ions and heating of Titan's atmosphere, Planet. Space Sci., In press, 2005. Shematovich, V.I., Johnson, R.E., Michael, M., Luhmann, J.G., Nitrogen loss from Titan. J. Geophys. Res., 108, 5086, 10.1029/2003JE002096, 2003.
DE: 0328 Exosphere
DE: 0343 Planetary atmospheres (5210, 5405, 5704)
DE: 2152 Pickup ions
DE: 2736 Magnetosphere/ionosphere interactions (2431)
DE: 6281 Titan
SC: Planetary Sciences [P]
MN: Fall Meeting 2005