HR: 1340h
AN: SA53B-1167    [Abstracts]
TI: Saturn's Ionosphere: Modeling Plasma Densities and Temperatures, Comparisons with Cassini
AU: * Moore, L
EM: moore@bu.edu
AF: Boston University, 725 Commonwealth Ave. Dept. of Astronomy, Boston, MA 02215 United States
AU: Mendillo, M
EM: mendillo@bu.edu
AF: Boston University, 725 Commonwealth Ave. Dept. of Astronomy, Boston, MA 02215 United States
AU: Mueller-Wodarg, I
EM: i.mueller-wodarg@imperial.ac.uk
AF: Boston University, 725 Commonwealth Ave. Dept. of Astronomy, Boston, MA 02215 United States
AU: Mueller-Wodarg, I
EM: i.mueller-wodarg@imperial.ac.uk
AF: Imperial College London, Space and Atmospheric Physics Group Prince Consort Road, London, SW7 2BW United Kingdom
AB: The Saturn-Thermosphere-Ionosphere-Model (STIM), a global circulation model (GCM) of Saturn's upper atmosphere, is used to calculate plasma densities and temperatures for a variety of latitudes and local times. Electron density profiles near the equator are compared with recent radio occultations from the Radio Science Subsystem (RSS) aboard Cassini. The measurements reveal a dawn/dusk asymmetry in both peak density -- roughly 1000 electrons/cc at dawn and 6000 electrons/cc at dusk -- and peak height -- around 2400 km at dawn and 1900 km at dusk. The observations are best reproduced by STIM when a significant flux of water is introduced into Saturn's atmosphere, at least 1 million H2O molecules per square cm per sec. Other implications of such a water flux, as well as current estimates of water in the Saturn system are discussed. In addition, modeled plasma temperatures are compared with temperatures inferred from the topside electron densities of the Cassini radio occultations under a variety of assumptions.
DE: 0335 Ion chemistry of the atmosphere (2419, 2427)
DE: 2419 Ion chemistry and composition (0335)
DE: 5729 Ionospheres (2459)
DE: 6929 Ionospheric physics (1240, 2400)
DE: 6934 Ionospheric propagation (0689, 2487, 3285, 4275, 4455)
SC: SPA-Aeronomy [SA]
MN: Fall Meeting 2005