In addition to early analysis of the 1990 Saturn storm data
( Barnet et al., 1992), Karkoschka and Tomasko (1993) have
analyzed 300-890 nm images and derived properties for the stratospheric hazes.
This analysis derives large haze optical depths north of 70
latitude,
essentially zero at mid-northern latitudes and about 0.2 at low and mid-southern
latitudes. They propose that latitudinal albedo and color variations in visible
light can be explained by variation in the size of tropospheric aerosols.
Preliminary observations involving near-simultaneous WFPC-1 and meridional FOS spectra were obtained in 1991 in an effort to characterize the latitudinal distribution of trace constituents in the stratosphere. This data set was the forerunner of a set planned for 1995. During 1995, the latitude of the sub-earth and sub-solar points will be near zero. Thus, the northern hemisphere will display the accumulated effects of enhanced insolation while the southern hemisphere will have emerged from the ring shadow and will display the effect of reduced insolation. The edge-on projection of the ring will remove a major obstacle, 889 nm reflection from the water ice in the ring particles, and allow high signal-to-noise images to be acquired in this spectral region where there is strong atmospheric absorption. A concentrated effort will be made to improve our understanding of the vertical structure of this atmosphere.