Search for Regularities in the Atmosphere of Jupiter

Exploratory studies are made of phenomena occurring in Jupiter's atmosphere in two distinct phenomenal regimes. The first study deals with variations in the planet's visible albedo over long periods of time. Photographic observations spanning the period 1967-1988 were reduced, calibrated relative to the disk average reflectivity of the planet, and arranged in a time series. The time series was then analyzed using periodograms and phase plots. A sharply defined periodicity is found in the North Temperate Belt (23^circN), having a period of 4.9 years. This period is not commensurate with any known periodicity bearing on the dynamics of Jupiter's atmosphere. The Equatorial Zone and South Equatorial Belt, although they exhibit small oscillations with similar periods, are dominated by aperiodic transitions between distinct states. The second study uses infrared observations from the Voyager 1 spacecraft to investigate the thermal structure of Jupiter's stratosphere. Data from the 3 mb and 9 mb pressure levels are separately averaged, grouped by latitude, and analyzed for evidence of longitudinal structure. Fourier transform methods are used to search for spatial periodicities, such as might result from planetary waves. Although some such periodicities are found, they are not considered strong evidence for planetary waves: none of them show the vertical extent or temporal persistence expected of such waves.