Jovian Wind Periodicity Revisited

Prior analysis of Jupiter's zonal wind field offered slight evidence of periodicity on short time scales, though time coverage was marginal (Simon-Miller et al. 2007 Icarus 186, 192-203). Though the winds are measured through tracking of tropospheric clouds, it was hoped that some relation could be found between stratospheric temperature oscillations (the Quasi-Quadrennial Oscillation) and tropospheric winds. However, complicating the analysis was the fact that the pressure levels of the tracked cloud features are unknown, and are spatially and temporally variable. Thermal wind analysis for a few of the dates showed cloud level variations could easily account for most of the wind speed variability, except at 7 deg. S latitude. New images, acquired in 2006 and 2007, have allowed the extension of the zonal wind time base, improving the periodogram analysis. We will present results based on our newest zonal wind and temperature profiles.