An Atlas of Variations in the Solar Constant Caused by Sunspot Blocking and Facular Emissions From 1874 to 1981

The purpose of this atlas is to present such a reconstruction for a period of slightly more than a century, for the use of atmospheric and solar physicists for whom a reconstruction may be of value. As stressed in later sections of this report, the atlas reconstructs only the short-term variations in S that have now been demonstrated to follow from day-to-day changes in surface solar activity. Moreover the reconstruction is based on the physically-improbable approximation of an infinite storage time within the sun: i.e., that the solar radiant flux blocked by sunspots is never released. As we point out in Section 3 and Appendix 3, however, the best observations now available fit this assumption rather well, suggesting that the storage time within the sun must be of the time scale of months or more. In time, after longer and better measurements of S from space have been accumulated the real storage time for blocked solar flux may be better defined. It is also possible that other, longer-term drifts or modulations in S., due perhaps to other solar mechanisms, will be established. In the interim, however, an atlas of the sort given here represents the best approximations that can now be given.