Jupiter cloud structure from Galileo images: Regional cloud systems

P.J. Gierasch, D.J. Banfield, M. Bell, E.A. Ustinov (Cornell), A. Vasavada, A.P. Ingersoll (Caltech), M.J.S. Belton (NOAO), Galileo Imaging Team

Large areas on Jupiter are laterally homogeneous to a high degree. Examples are the core of the Great Red Spot, the dark collar surrounding the Red Spot, and the core of a typical five micron bright spot. Galileo data from many of these regions exists with a wide range of observing and illumination angles, and at a set of wavelengths representing strong and weak methane bands plus a nearby methane continuum. These sets of data show that the general vertical structure is an upper troposphere haze over a thicker cloud, which in turn overlies a deep haze. The elevation and albedo of the upper troposphere haze varies greatly from region to region. For example, the elevation is particularly high in the core of the Red Spot, and particularly low in the dark ring surrounding the Red Spot. The optical depth of the denser cloud beneath the haze also varies from region to region, and is very small near five micron hot spots. This cloud, regionally, is remarkably uniform in height (pressure level). It is probably ammonia condensate. Maps of cloud properties are presented.