Solar butterfly diagram (source code)

= Solar butterfly diagram

A solar butterfly diagram plots sunspot occurrence or magnetic flux against latitude and time. New-cycle sunspot belts appear at middle latitudes and migrate toward the equator, producing successive wing-shaped patterns. Magnetic butterfly diagrams additionally show poleward flux transport and polar-field reversals. The diagram constrains both <Parker dynamo wave> propagation and magnetic transport in <flux-transport solar dynamos>.