Current scientific models of the solar dynamo can be adjusted to reproduce the 11-year solar cycle. Longer periodicities may be predicted by the models, but at this stage the models are not sufficient to reproduce all of the changes observed in the solar cycle. The solar dynamo generates the magnetic field that causes the solar cycle (also called the 22-year solar cycle, the 11-year sunspot cycle, or the magnetic cycle).
Some important questions about the source of irradiance variations:
A longitudinal magnetogram from the MDI instrument on SoHO on October 30, 2001. White regions have an outward (Northern) polarity while black regions are an inward (Southern) polarity. The tilts are due to the differential rotation of the Sun.
All of these changes in solar irradiance are linked to changes in the solar magnetic field. Even the smallest magnetic features can have an observable connection to the irradiance output. The magnetic field is generated in the solar interior. Therefore, to fully understand the mechanisms which cause irradiance variations, we require: