Solar Physics

, Volume 291, Issue 9–10, pp 2951–2965 | Cite as

The Impact of the Revised Sunspot Record on Solar Irradiance Reconstructions

  • G. KoppEmail author
  • N. Krivova
  • C. J. Wu
  • J. Lean
Sunspot Number Recalibration


Reliable historical records of the total solar irradiance (TSI) are needed to assess the extent to which long-term variations in the Sun’s radiant energy that is incident upon Earth may exacerbate (or mitigate) the more dominant warming in recent centuries that is due to increasing concentrations of greenhouse gases. We investigate the effects that the new Sunspot Index and Long-term Solar Observations (SILSO) sunspot-number time series may have on model reconstructions of the TSI. In contemporary TSI records, variations on timescales longer than about a day are dominated by the opposing effects of sunspot darkening and facular brightening. These two surface magnetic features, retrieved either from direct observations or from solar-activity proxies, are combined in TSI models to reproduce the current TSI observational record. Indices that manifest solar-surface magnetic activity, in particular the sunspot-number record, then enable reconstructing historical TSI. Revisions of the sunspot-number record therefore affect the magnitude and temporal structure of TSI variability on centennial timescales according to the model reconstruction methods that are employed. We estimate the effects of the new SILSO record on two widely used TSI reconstructions, namely the NRLTSI2 and the SATIRE models. We find that the SILSO record has little effect on either model after 1885, but leads to solar-cycle fluctuations with greater amplitude in the TSI reconstructions prior. This suggests that many eighteenth- and nineteenth-century cycles could be similar in amplitude to those of the current Modern Maximum. TSI records based on the revised sunspot data do not suggest a significant change in Maunder Minimum TSI values, and from comparing this era to the present, we find only very small potential differences in the estimated solar contributions to the climate with this new sunspot record.


Total solar irradiance TSI Solar variability Climate change 



We gratefully acknowledge the support of NASA’s SORCE (NAS5-97045) and SIST (NNX15AI51G) for this effort. J. Lean appreciates collaboration with Odele Coddington in developing the NOAA Solar Irradiance CDR. The authors also appreciate helpful suggestions from the referee. The SILSO data are courtesy of WDC-SILSO, Royal Observatory of Belgium, Brussels. Figure 1 includes data from (NIMBUS7/ERB, ERBS/ERBE, NOAA9, and NOAA10); (ACRIM1, ACRIM2, and ACRIM3); the VIRGO team via ; (SORCE/TIM); the PICARD/PREMOS team (personal communication), A. Fehlmann, 2014; and (TCTE/TIM).

Disclosure of Potential Conflicts of Interest

The authors declare that they have no conflicts of interest.


  1. Allen, C.W.: 1976, Astrophysical Quantities, 3rd edn. Athlone, Oxford. Google Scholar
  2. Balmaceda, L.A., Solanki, S.K., Krivova, N.A., Foster, S.: 2009, A homogeneous database of sunspot areas covering more than 130 years. J. Geophys. Res. 114, A07104. ADSCrossRefGoogle Scholar
  3. Balmaceda, L.A., Solanki, S.K., Krivova, N.A., Foster, S.: 2010, Reply to comment by P. Foukal on “A homogeneous database of sunspot areas covering more than 130 years”. J. Geophys. Res. 115, A09103. ADSCrossRefGoogle Scholar
  4. Brandt, P.N., Stix, M., Weinhardt, H.: 1994, Modelling solar irradiance variations with an area dependent photometric sunspot index. Solar Phys. 152, 119.  DOI. ADSCrossRefGoogle Scholar
  5. Clette, F., Svalgaard, L., Vaquero, J.M., Cliver, E.W.: 2015, Revisiting the sunspot number. A 400-year perspective on the solar cycle. Space Sci. Rev. 186(1–4), 35.  DOI. ADSGoogle Scholar
  6. Coddington, O., Lean, J.: 2015, Climate algorithm theoretical basis document: total solar irradiance and solar spectral irradiance. CRDP-ATBD-0612, Available from
  7. Coddington, O., Lean, J.L., Pilewskie, P., Snow, M., Lindholm, D.: 2015, A solar irradiance climate data record. Bull. Am. Meteorol. Soc.  DOI. Google Scholar
  8. Dasi-Espuig, M., Jiang, J., Krivova, N.A., Solanki, S.K.: 2014, Modelling total solar irradiance since 1878 from simulated magnetograms. Astron. Astrophys. 570, A23.  DOI. ADSCrossRefGoogle Scholar
  9. Delaygue, G., Bard, E.: 2011, An Antarctic view of beryllium-10 and solar activity for the past millennium. Clim. Dyn. 36, 2201.  DOI. CrossRefGoogle Scholar
  10. Eddy, J.: 1976, The Maunder minimum. Science 192, 4245. CrossRefGoogle Scholar
  11. Ermolli, I., Matthes, K., Dudok de Wit, T., Krivova, N.A., Tourpali, K., Weber, M., et al.: 2013, Recent variability of the solar spectral irradiance and its impact on climate modelling. Atmos. Chem. Phys. 13, 394.  DOI. CrossRefGoogle Scholar
  12. Fligge, M., Solanki, S.K.: 1997, Inter-cycle variations of solar irradiance: sunspot areas as a pointer. Solar Phys. 173, 427.  DOI. ADSCrossRefGoogle Scholar
  13. Foukal, P.: 1981, Sunspots and changes in the global output of the Sun. In: Cram, L.E., Thomas, J.H. (eds.) Proc. the Physics of Sunspots, 1981, Sunspot, NM, A83-18101, 391. Google Scholar
  14. Foukal, P.: 2014, An explanation of the differences between the sunspot area scales of the Royal Greenwich and Mt. Wilson observatories, and the SOON program. Solar Phys. 289, 1517.  DOI. ADSCrossRefGoogle Scholar
  15. Fröhlich, C.: 2006, Solar irradiance variability since 1978: revision of the PMOD composite during solar cycle 21. Space Sci. Rev. 125, 53.  DOI. ADSCrossRefGoogle Scholar
  16. Fröhlich, C., Lean, J.: 1998, The Sun’s total irradiance: cycles, trends and climate change uncertainties since 1976. Geophys. Res. Lett. 25, 4377. ADSCrossRefGoogle Scholar
  17. Gray, L.J., Beer, J., Geller, M., Haigh, J.D., Lockwood, M., Matthes, K., et al.: 2010, Solar influences on climate. Rev. Geophys. 48, RG4001.  DOI. ADSCrossRefGoogle Scholar
  18. Haigh, J.: 2007, The Sun and the Earth’s climate. Living Rev. Solar Phys. 4, 2.  DOI. ADSMathSciNetCrossRefGoogle Scholar
  19. Hartmann, D.L.: 1994, Global Physical Climatology, International Geophysics Series 56, Academic Press, London. CrossRefGoogle Scholar
  20. Hathaway, D.H., Wilson, R.M., Reichmann, E.J.: 2002, Group sunspot numbers: sunspot cycle characteristics. Solar Phys. 211, 357.  DOI. ADSCrossRefGoogle Scholar
  21. Hoyt, D.V., Eddy, J.A.: 1982, An atlas of variations in the solar constant caused by sunspot blocking and facular emissions from 1874 to 1981, National Center for Atmospheric Research. NCAR technical note TN-194+STR, Boulder, Colorado. Google Scholar
  22. Hoyt, D.V., Schatten, K.H.: 1998, Group sunspot numbers: a new solar activity reconstruction. Solar Phys. 181, 491.  DOI. ADSCrossRefGoogle Scholar
  23. Hoyt, D.V., Schatten, K.H., Nesmes-Ribes, E.: 1994, The one hundredth year of Rudolf Wolf’s death: do we have the correct reconstruction of solar activity? Geophys. Res. Lett. 21, 2067. ADSCrossRefGoogle Scholar
  24. Ineson, S., Scaife, A.A., Knight, J.R., Manners, J.C., Dunstone, N.J., Gray, L.J., Haigh, J.D.: 2011, Solar forcing of winter climate variability in the Northern Hemisphere. Nat. Geosci.  DOI. Google Scholar
  25. Jiang, J., Cameron, R., Schmitt, D., Schüssler, M.: 2010, Modeling the Sun’s open magnetic flux and the heliospheric current sheet. Astrophys. J. 709, 301. ADSCrossRefGoogle Scholar
  26. Kopp, G., Lawrence, G.: 2005, The total irradiance monitor (TIM): instrument design. Solar Phys. 230(1), 91.  DOI. ADSCrossRefGoogle Scholar
  27. Kopp, G., Lean, J.L.: 2011, A new, lower value of total solar irradiance: evidence and climate significance. Geophys. Res. Lett. 38, L01706.  DOI. ADSCrossRefGoogle Scholar
  28. Kren, A.C.: 2015, Investigating the role of the Sun, the quasi-biennial oscillation, and the pacific decadal oscillation on decadal climate variability of the stratosphere, University of Colorado at Boulder (thesis). Google Scholar
  29. Krivova, N.A., Balmaceda, L., Solanki, S.K.: 2007, Reconstruction of solar total irradiance since 1700 from the surface magnetic flux. Astron. Astrophys. 467, 335. ADSCrossRefGoogle Scholar
  30. Krivova, N.A., Solanki, S.K., Unruh, Y.C.: 2011, Towards a long-term record of solar total and spectral irradiance. J. Atmos. Solar-Terr. Phys. 73, 223. ADSCrossRefGoogle Scholar
  31. Krivova, N.A., Vieira, L.E.A., Solanki, S.K.: 2010, Reconstruction of solar spectral irradiance since the Maunder minimum. J. Geophys. Res. 115, A12112.  DOI. ADSCrossRefGoogle Scholar
  32. Lean, J.: 2000, Evolution of the Sun’s spectral irradiance since the Maunder minimum. Geophys. Res. Lett. 27, 2425. ADSCrossRefGoogle Scholar
  33. Lean, J.L.: 2010, Cycles and Trends in Solar Irradiance and Climate, Wiley Interdisciplinary Reviews. Climate Change 1.  DOI.
  34. Lean, J.L., Rind, D.H.: 2008, How natural and anthropogenic influences alter global and regional surface temperatures: 1889 to 2006. Geophys. Res. Lett. 35, L18701.  DOI. ADSCrossRefGoogle Scholar
  35. Lean, J., Skumanich, A., White, O.R.: 1992, Estimating the Sun’s radiative output during the Maunder minimum. Geophys. Res. Lett. 19, 1591. ADSCrossRefGoogle Scholar
  36. Lean, J.L., Cook, J., Marquette, W., Johannesson, A.: 1998, Magnetic sources of the solar irradiance cycle. Astrophys. J. 492, 390. ADSCrossRefGoogle Scholar
  37. Lean, J.L., White, O.R., Livingston, W.C., Picone, J.M.: 2001, Variability of a composite chromospheric irradiance index during the 11-year activity cycle and over longer time periods. J. Geophys. Res. 106, 10645. ADSCrossRefGoogle Scholar
  38. Lean, J., Rottman, G., Harder, J., Kopp, G.: 2005, SORCE contributions to new understanding of global change and solar variability. Solar Phys. 230, 27.  DOI. ADSCrossRefGoogle Scholar
  39. Lockwood, M., Owens, M.J., Barnard, L., Usoskin, I.G.: 2016, Tests of sunspot number sequences: 3. Effects of regression procedures on the calibration of historic sunspot data, Solar Phys.  DOI. arXiv. Google Scholar
  40. Radick, R.R., Lockwood, G.W., Skiff, B.A., Baliunas, S.L.: 1998, Patterns of variation among sun-like stars. Astrophys. J. Suppl. 118, 239.  DOI. ADSCrossRefGoogle Scholar
  41. Rottman, G.: 2005, The SORCE mission. Solar Phys. 230, 7.  DOI. ADSCrossRefGoogle Scholar
  42. Solanki, S.K., Krivova, N.A.: 2006, Solar variability of possible relevance for planetary climates. Space Sci. Rev. 125, 25.  DOI. ADSCrossRefGoogle Scholar
  43. Solanki, S.K., Krivova, N.A., Haigh, J.D.: 2013, Solar irradiance variability and climate. Annu. Rev. Astron. Astrophys. 51, 311.  DOI. ADSCrossRefGoogle Scholar
  44. Solanki, S.K., Schüssler, M., Fligge, M.: 2002, Secular variation of the Sun’s magnetic flux. Astron. Astrophys. 383, 706.  DOI. ADSCrossRefGoogle Scholar
  45. Skupin, J., Weber, M., Bovensmann, H., Burrows, J.P.: 2004, The Mg ii solar activity proxy indicator derived from GOME and SCIAMACHY. In: Lacoste, H., Ouwehand, L. (eds.) Proc. ENVISAT & ERS Symposium SP-572, ESA, Noordwijk. Google Scholar
  46. Snow, M.J., Weber, M., Machol, J., Viereck, R., Richard, E.: 2014, Comparison of magnesium ii core-to-wing ratio observations during solar minimum 23/24. J. Space Weather Space Clim. 4, A04.  DOI. CrossRefGoogle Scholar
  47. Steinhilber, F., Beer, J., Fröhlich, C.: 2009, Total solar irradiance during the Holocene. Geophys. Res. Lett. 36, L19704. ADSCrossRefGoogle Scholar
  48. Steinhilber, F., Abreu, J.A., Beer, J., Brunner, I., Christl, M., Fischer, H., et al.: 2012, 9,400 years of cosmic radiation and solar activity from ice cores and tree rings. Proc. Natl. Acad. Sci. USA 109(16), 5967.  DOI. ADSCrossRefGoogle Scholar
  49. Svalgaard, L., Schatten, K.H.: 2016, Reconstruction of the sunspot group number: the backbone method. Solar Phys.  DOI. Google Scholar
  50. Unruh, Y.C., Solanki, S.K., Fligge, M.: 1999, The spectral dependence of facular contrast and solar irradiance variations. Astron. Astrophys. 345, 635. ADSGoogle Scholar
  51. Usoskin, I.G.: 2013, A history of solar activity over millennia. Living Rev. Solar Phys. 10, 1.  DOI. ADSCrossRefGoogle Scholar
  52. Usoskin, I.G., Kovaltsov, G.A., Lockwood, M., Mursula, K., Owens, M., Solanki, S.K.: 2016, A new calibrated sunspot group series since 1749: statistics of active day fractions. Solar Phys.  DOI. Google Scholar
  53. Viereck, R.A., Floyd, L.E., Crane, P.C., Woods, T.N., Knapp, B.G., Rottman, G., et al.: 2004, A composite Mg ii index spanning from 1978 to 2003. Space Weather 2, S10005.  DOI. ADSCrossRefGoogle Scholar
  54. Vieira, L.E.A., Solanki, S.K., Krivova, N.A., Usoskin, I.: 2011, Evolution of the solar irradiance during the Holocene. Astron. Astrophys. 531, A6.  DOI. ADSCrossRefGoogle Scholar
  55. Wang, Y.M., Lean, J.L., Sheeley, N.R. Jr.: 2005, Modeling the Sun’s magnetic field and irradiance since 1713. Astrophys. J. 625, 522.  DOI. ADSCrossRefGoogle Scholar
  56. Yeo, K.L., Krivova, N.A., Solanki, S.K., Glassmeier, K.H.: 2014, Reconstruction of total and spectral solar irradiance from 1974 to 2013 based on KPVT, SoHO/MDI, and SDO/HMI observations. Astron. Astrophys. 570, A85. ADSCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2016

Authors and Affiliations

  1. 1.LASPUniv. of ColoradoBoulderUSA
  2. 2.Max-Planck-Institut für SonnensystemforschungGöttingenGermany
  3. 3.Space Science DivisionNaval Research LaboratoryWashingtonUSA

Personalised recommendations