Long-term drift of the coronal source magnetic flux and the total solar irradiance

Lockwood, M. ORCID: https://orcid.org/0000-0002-7397-2172 and Stamper, R. (1999) Long-term drift of the coronal source magnetic flux and the total solar irradiance. Geophysical Research Letters, 26 (16). pp. 2461-2464. ISSN 0094-8276 doi: 10.1029/1999GL900485

Abstract/Summary

We test the method of Lockwood et al. [1999] for deriving the coronal source flux from the geomagnetic aa index and show it to be accurate to within 12% for annual means and 4.5% for averages over a sunspot cycle. Using data from four solar constant monitors during 1981-1995, we find a linear relationship between this magnetic flux and the total solar irradiance. From this correlation, we show that the 131% rise in the mean coronal source field over the interval 1901-1995 corresponds to a rise in the average total solar irradiance of {\Delta}I = 1.65 +/- 0.23 Wm^{-2}.