Saturn's cloud structure inferred from Cassini ISS

Using high-resolution Cassini ISS images with wavelengths ranging from the ultraviolet to the near infrared, we have retrieved Saturn's atmospheric aerosol structure and properties for a broad range of latitudes in the southern hemisphere. The observations are consistent with two distinct layers of haze above a scattered cloud. Each layer is characterized by a vertical location, an optical thickness, and an effective mean particle size, all of which vary with latitude. The tropospheric haze is optically thickest and extends to the greatest heights (∼40 mbar) over the equator; its top surface is at significantly greater depths (∼150 mbar) at mid-latitudes. The height of the haze correlates well with position of the tropopause as indicated by the temperature field. Beneath this haze, we find a scattered denser cloud responsible for small-scale contrasts at an average depth of 1.75 ± 0.4 bar, with some features as deep as 2.5 bar or greater.