Long-term changes in Saturn's atmospheric belts and zones

An analysis of more than 200 photographs of Saturn taken in three spectral ranges from 1890 to 1984, has been performed in order to detect possible seasonal changes in the latitudinal position of the atmospheric belts and in their morphological structure. Annual saturnigraphic latitudes of the belts do not show a systematic trend associated to the seasonal forcing. Structural changes seem to be sporadic and more common to the equatorial belts and zone, a region occupied by a high speed zonal jet. In some occasions they appeared related to activity in form of white clouds (probably of convective origin)