Time series of regular full-disc solar observations acquired in white light and at the Ca II K and Halpha lines provide direct information on magnetic regions on the Sun with an almost complete daily coverage over the last century.
This makes them extremely important for studies of the solar magnetism over long time scales. Here, we first provide an overview of the most prominent archives of...
The solar cycle is driven by the emergence and evolution of active regions on the Sun’s surface, which play a critical role in the Sun's magnetic dynamics. One of the fundamental properties of these regions is the tilt angle, which describes the inclination of a sunspot group’s axis relative to the solar equator. Tilt angles are essential for understanding the solar dynamo, as they contribute...
Direct measurements of solar irradiance started in 1978, which is a rather short period for climate studies.
Irradiance variations on timescales of days and longer are attributed to the evolution of the solar surface magnetic field, which allows irradiance reconstructions for periods that appropriate data describing solar surface magnetism exist.
In particular, such models require...
