HR: 0800h
AN: P51B-1436    [Abstracts]
TI: An Updated View of Saturn's Upper Atmosphere From a Reanalysis of the Voyager 1 and 2 UVS Occultations
AU: * Vervack, R J
EM: Ron.Vervack@jhuapl.edu
AF: The Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723-6099 United States
AB: The Voyager 1 and 2 Ultraviolet Spectrometer (UVS) solar and stellar occultation data set represents one of the primary, pre-Cassini sources of information that we have on the neutral upper atmosphere of Saturn. Despite its importance, however, the full set of occultations has never received a consistent analysis, and the results derived from the initial analyses over twenty years ago left questions about the temperature and density profiles unanswered. We have reanalyzed all six of the UVS occultations (three solar and three stellar) to provide an up-to-date, pre-Cassini view of Saturn's upper atmosphere. This analysis has resulted in altitude profiles for H$_2$, H, CH$_4$, C$_2$H$_2$, C$_2$H$_4$, and C$_2$H$_6$ as well as information on the temperature structure. In addition, our analysis provides an explanation for the two different thermospheric temperatures derived in earlier analyses (400-450 K versus 800 K) as well as the unusual shape of the total density profile noted by Hubbard et al. (Icarus, 130, 404-425, 1997). The results of our reanalysis will provide a useful baseline for interpreting new data from Cassini, particularly in the context of change over the past two decades.
DE: 5700 PLANETOLOGY: FLUID PLANETS
DE: 5704 Atmospheres--composition and chemistry
DE: 5707 Atmospheres--structure and dynamics
DE: 6275 Saturn
DE: 0343 Planetary atmospheres (5405, 5407, 5409, 5704, 5705, 5707)
SC: Planetary Sciences [P]
MN: 2004 AGU Fall Meeting