Analysis of motions of Jupiter's great red SPOT and white ovals

Self-consistent longitude and latitude measurements of Jupiter's Great Red Spot and white ovals made from photographic plates obtained in the course of twenty years of operation of New Mexico State University's planetary patrol program are analyzed. The zonal motions of all four cloud systems are characterized by abrupt accelerations followed by long periods of recovery. The Great Red Spot's 90-day period zonal oscillation has persisted with no significant phase shift throughout the entire time interval, and a new determination of its parameters is presented. No such dominant single-frequency oscillations were found in the zonal motions of the ovals, although weak modes are suggested during limited time intervals. Evidence is presented which may associate the episodic zonal behavior with deep-seated convective activity. A significant degree of meridional interaction between the Great Red Spot and ovals is shown to exist, confirming earlier indications.