HR: 11:35h
AN: P42A-06    [Abstracts]
TI: The Nature of the Plasma Density Enhancements near Titan
AU: * Eviatar, A
EM: arkee@daphne.tau.ac.il
AF: Tel Aviv University, Ramat Aviv, Tel Aviv, 40295 Israel
AU: Crary, F J
AF: Southwest Research Institute , 6220 Culebra Rd, San Antonio,, TX 78228 United States
AU: Goldstein, R
AF: Southwest Research Institute , 6220 Culebra Rd, San Antonio,, TX 78228 United States
AU: Sittler, E C
AF: NASA Goddard SFC , MC 692, Greenbelt,, MD 20771-000 United States
AU: Young, D T
AF: Southwest Research Institute , 6220 Culebra Rd, San Antonio,, TX 78228 United States
AB: At the time of the Voyager 1 close encounter with Titan, enhancements of density and sharp decreases of electron temperature were observed by the PLS instrument. These were interpreted by Eviatar et al.(1982, JGR, 87, 8091) as plumes drawn out of the ionosphere of Titan by the corotation electric field. A few smaller plumes were identified inside and outside Titan orbit and their displacements correlated with variations in solar wind dynamic pressure observed by Voyager PLS one and two corotation periods earlier. The subplumes were understood to be the remnants of plasma drawn out earlier and the rate of decay was associated with the assimilation of the plume into the ambient plasma. This model was disputed by Goertz (GRL, 1983, 10, 455) who viewed them as blobs of plasmas detached by centrifugal force from the central body of Saturn plasma in the inner magnetosphere. The Voyager PLS instrument was unable to make a firm composition determination which would have resolved the question, although Hartle et al. (JGR, 1982, 87, 1383) did identify an ion of mass to charge ratio 28 in the near-Titan plasma. The Cassini CAPS instrument will be able to determine the composition of the plumes/blobs and to resolve the issue during the Titan encounter of October 26, 2004. Results of the composition analysis will be presented at the December AGU.
DE: 6280 Saturnian satellites
DE: 2756 Planetary magnetospheres (5443, 5737, 6030)
SC: Planetary Sciences [P]
MN: 2004 AGU Fall Meeting