Max-Planck-Institute for Aeronomy, D-37191 Katlenburg-Lindau, Germany
solanki@linmpi.mpg.de
"Long-term changes in solar irradiance"
Measurements of solar irradiance with the necessary precision to reveal the
sun's intrinsic variability started in 1978. These measurements have
revealed dips in solar brightness due to the passage of sunspots across the
solar disc on a solar rotation time scale and a remarkable increase of the
solar irradiance at solar activity maximum. In order to uncover a possible
connection between solar irradiance variations and climate it is necessary
to extend the irradiance record to earlier times with the help of models.
A brief introduction to the results of the measurements and our current understanding of the variability they reveal is given, followed by an overview of the efforts to reconstruct irradiance or the underlying magnetic field at earlier times.