Solar Physics

, Volume 273, Issue 1, pp 221–230 | Cite as

A Standard Law for the Equatorward Drift of the Sunspot Zones

  • D. H. HathawayEmail author


The latitudinal location of the sunspot zones in each hemisphere is determined by calculating the centroid position of sunspot areas for each solar rotation from May 1874 to June 2011. When these centroid positions are plotted and analyzed as functions of time from each sunspot cycle maximum, there appear to be systematic differences in the positions and equatorward drift rates as a function of sunspot cycle amplitude. If, instead, these centroid positions are plotted and analyzed as functions of time from each sunspot cycle minimum, then most of the differences in the positions and equatorward drift rates disappear. The differences that remain disappear entirely if curve fitting is used to determine the starting times (which vary by as much as eight months from the times of minima). The sunspot zone latitudes and equatorward drift measured relative to this starting time follow a standard path for all cycles with no dependence upon cycle strength or hemispheric dominance. Although Cycle 23 was peculiar in its length and the strength of the polar fields it produced, it too shows no significant variation from this standard. This standard law, and the lack of variation with sunspot cycle characteristics, is consistent with dynamo wave mechanisms but not consistent with current flux transport dynamo models for the equatorward drift of the sunspot zones.


Solar cycle, observations Sunspots, statistics Sunspots, velocity 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Babcock, H.W.: 1961, Astrophys. J. 133, 572. ADSCrossRefGoogle Scholar
  2. Becker, U.: 1954, Z. Astrophys. 34, 129. ADSGoogle Scholar
  3. Carrington, R.C.: 1858, Mon. Not. Roy. Astron. Soc. 19, 1. ADSGoogle Scholar
  4. Harvey, K.L., White, O.R.: 1999, J. Geophys. Res. 104(A9), 19 759. ADSCrossRefGoogle Scholar
  5. Hathaway, D.H.: 2010, Living Rev. Solar Phys. 7, 1. ADSGoogle Scholar
  6. Hathaway, D.H., Rightmire, L.: 2010, Science 327, 1350. ADSCrossRefGoogle Scholar
  7. Hathaway, D.H., Rightmire, L.: 2011, Astrophys. J. 729, 80. ADSCrossRefGoogle Scholar
  8. Hathaway, D.H., Wilson, R.M., Reichmann, R.J.: 1994, Solar Phys. 151, 177. ADSCrossRefGoogle Scholar
  9. Hathaway, D.H., Nandy, D., Wilson, R.M., Reichmann, R.J.: 2003, Astrophys. J. 589, 665. ADSCrossRefGoogle Scholar
  10. Leighton, R.B.: 1969, Astrophys. J. 156, 1. ADSCrossRefGoogle Scholar
  11. Maunder, E.W.: 1903, Observatory 26, 329. ADSGoogle Scholar
  12. Maunder, E.W.: 1904, Mon. Not. Roy. Astron. Soc. 64, 747. ADSGoogle Scholar
  13. McKinnon, J.A.: 1987, Sunspot Numbers 1610 – 1986 (Based on The Sunspot-Activity in the Years 1610 – 1960, by Prof. M. Waldmeier, Copyright 1961 Swiss Federal Observatory, Zurich, Switzerland). UAG Reports UAG-95, National Geophysical Data Center, NOAA, Boulder. Google Scholar
  14. Nandy, D., Choudhuri, A.R.: 2002, Science 296, 1671. ADSCrossRefGoogle Scholar
  15. Nandy, D., Muñoz-Jaramillo, A., Martens, P.C.H.: 2011, Nature 471, 80. ADSCrossRefGoogle Scholar
  16. Norton, A.A., Gallagher, J.C.: 2010, Solar Phys. 261, 193. ADSCrossRefGoogle Scholar
  17. Press, W.H., Flannery, B.P., Teukolsky, S.A., Vetterling, W.T.: 1986, Numerical Recipes, Cambridge University Press, Cambridge. Google Scholar
  18. Spörer, G.: 1880, Publ. Astrophys. Potsdam 2(5), 1. Google Scholar
  19. Spörer, G.: 1889, Bull. Astron., Ser. I 6, 60. Google Scholar
  20. Waldmeier, M.: 1935, Astron. Mitt. Zurich 14(133), 105. ADSGoogle Scholar
  21. Waldmeier, M.: 1955, Ergebnisse und Probleme der Sonnenforschung, 2nd edn., Geest & Portig, Leipzig. Google Scholar
  22. Waldmeier, M.: 1961, The Sunspot-Activity in the Years 1610 – 1960, Schulthess Co., Swiss Federal Observatory, Zurich. Google Scholar
  23. Yoshimura, H.: 1975, Astrophys. J. 201, 740. MathSciNetADSCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2011

Authors and Affiliations

  1. 1.NASA Marshall Space Flight CenterHuntsvilleUSA

Personalised recommendations