Possible period of Jovian activity and possibility of seasons

A study was made of the factors which might be responsible for the long- and short-period variations of the physical and photometric properties of the Jovian atmosphere. The investigation was based on published observational data for the year 1953-1983 relating to the relative brightness distribution along the central meridian of the planet. The spectral ranges considered were 0.51 and 0.37-0.40 microns. During the considered period the greatest reflectivity variations occurred in the southern and northern tropical zones (STrZ and NTrZ), which were alternately the brightest details on the disk.