  The Voyager 1 and 2 Ultraviolet Spectrometer (UVS) solar and stellar
occultation dataset 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, nor complete, analysis, and the results derived from the initial
analyses over thirty 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. From the Voyager UVS data, we have determined vertical
profiles for H2, H, CH4, C2H2 , C2H4, and C2H6, as well as temperature. Our
analysis also provides explanations for the two different thermospheric
temperatures derived in earlier analyses (400-450 K versus 800 K) and for the
unusual shape of the total density profile noted by Hubbard et al. (1997).
Aside from inverting the occultation data to retrieve densities and
temperatures, we have investigated the atmospheric structure through a series
of photochemical models to infer the strength of atmospheric mixing and other
physical and chemical properties of Saturn's mesopause region during the
Voyager flybys. We find that the data exhibit considerable variability in the
vertical profiles for methane, suggesting variations in vertical winds or the
eddy diffusion coefficient as a function of latitude and/or time in Saturn's
upper atmosphere. 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 three decades.
