Solar irradiance variations due to active regions

Questions regarding changes in solar irradiance due to activity are important, since such changes may have a significant effect on the earth's climate. Solar irradiance measurements conducted outside the earth's atmosphere and, therefore, not affected by it have become possible by utilizing for such measurements satellites, such as the Nimbus 7 and the Solar Maximum Mission satellite (ACRIM experiment). The present investigation has the objective to show that a combination of sunspots and faculae is capable of representing the observed variations in the values of ACRIM data to a satisfactory degree, given the current level of uncertainties in the ground-based data.