Global Patterns of Cloud Distribution

Global distribution of clouds.  The band of clouds in the center is the "intertropical convergence zone".  The clouds are concentrated there because of rising airmasses at the equator (condensation, cloud formation), and because the converging air masses are rich in moisture.

A view of the south polar regions.  The image shows a series of large low-pressure (cyclone) systems in the sub-polar region. The quite regular distribution of these cyclones is at least in part due to the fact that this region is located entirely over the oceans.  If there were a mix of land and sea areas, such as in the northern hemisphere, weather patterns would be more irregular.