HR: 16:15h
AN: P34A-04    [Abstracts]
TI: Waves in Titan's thermosphere
AU: * Mueller-Wodarg, I C
EM: i.mueller-wodarg@imperial.ac.uk
AF: Space and Atmospheric Physics Laboratory, Imperial College London, Prince Consort Road, London, SW7 2BW United Kingdom
AU: Yelle, R V
EM: yelle@lpl.arizona.edu
AF: Lunar and Planetary Laboratory, University of Arizona, 1629 E. University Blvd., Tucson, AZ 85721-0092 United States
AU: Borggren, N
EM: borggren@lpl.arizona.edu
AF: Lunar and Planetary Laboratory, University of Arizona, 1629 E. University Blvd., Tucson, AZ 85721-0092 United States
AU: Waite, H
EM: hunterw@umich.edu
AF: Department of Atmospheric, Oceanic, and Space Sciences, University of Michigan, Street, Ann Arbor, MI 48109-2143
AB: Observations by Cassini's INMS instrument during the Titan A flyby on Oct 26, 2004 provided first in-situ observations of Titan's upper atmosphere between around 1075 and 1800 km altitude. From the observed densities of N₂ and CH₄ we derived thermospheric temperatures, which on average have an isothermal value of around 148 K. However, we also found strong perturbations around this mean with amplitudes of up to 10 K and wavelengths of between 60 and 220 km. Since the spacecraft during its flyby moved both horizontally and vertically, these perturbations can in principle be interpreted as horizontally or vertically propagating waves. We will discuss this issue and present a spectral analysis to characterize their global properties. A similar investigation will be presented for the T5 flyby in April 2005 and comparisons will be made. Finally, suggestions will be presented regarding the origin of these waves and their importance as sources of momentum and energy for the background atmosphere.
DE: 6007 Atmospheres--structure and dynamics
DE: 6280 Saturnian satellites
SC: Planetary Sciences [P]
MN: 2005 Joint Assembly