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Solar Physics

, Volume 125, Issue 1, pp 143–155 | Cite as

On the level of skill in predicting maximum sunspot number: A comparative study of single variate and bivariate precursor techniques

  • Robert M. Wilson
Article

Abstract

Precursor prediction techniques have generally performed well in predicting the maximum amplitude of sunspot cycles, based on cycles 10–21. Single variate methods based on minimum sunspot amplitude have reliably predicted the size of the sunspot cycle 9 out of 12 times, where a reliable prediction is defined as one having an observed maximum amplitude within the prediction interval (determined from the average error). On the other hand, single variate methods based on the size of the geomagnetic minimum have reliably predicted the size of the sunspot cycle 8 of 10 times (geomagnetic data are only available since about cycle 12). Bivariate prediction methods have, thus far, performed flawlessly, giving reliable predictions 10 out of 10 times (bivariate methods are based on sunspot and geomagnetic data). For cycle 22, single variate methods (based on geomagnetic data) suggest a maximum amplitude of about 170 ± 25, while bivariate methods suggest a maximum amplitude of about 140 ± 15; thus, both techniques suggest that cycle 22 will be of smaller maximum amplitude than that observed during cycle 19, and possibly even smaller than that observed for cycle 21. Compared to the mean cycle, cycle 22 is presently behaving as if it is a + 2.6σ cycle (maximum amplitude about 225). It appears then that either cycle 22 will be the first cycle not to be reliably predicted by the combined precursor techniques (i.e., cycle 22 is an anomaly, a statistical outlier) or the deviation of cycle 22 relative to the mean cycle will substantially decrease over the next 18 months. Because cycle 22 is a large amplitude cycle, maximum smoothed sunspot number is expected to occur early in 1990 (between December 1989 and May 1990).

Keywords

Maximum Amplitude Sunspot Number Prediction Interval Reliable Prediction Sunspot Cycle 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. Bray, R. J. and Loughhead, R. E.: 1964, Sunspots, Chapman & Hall, London.Google Scholar
  2. Brown, G. M.: 1988, Nature 333, 121.Google Scholar
  3. Brown, G. M. and Simon, P. A.: 1986, in P. A. Simon, G. Heckman, and M. A. Shea (eds.), Solar-Terrestrial Predictions: Proceedings of a Workshop at Meudon, France, June 18–22, 1984, NOAA Space Environment Laboratory, Boulder, Colorado, p. 1.Google Scholar
  4. Eddy, J. A.: 1977, in O. R. White (ed.), The Solar Output and Its Variation, Colorado Associated University Press, Boulder, Colorado, p. 51.Google Scholar
  5. Gonzalez, G. and Schatten, K. H.: 1987, Solar Phys. 114, 189.Google Scholar
  6. Greer, M. S. and Hirman, J. W.: 1989, Eos, Trans. AGU 70, 186.Google Scholar
  7. Hirman, J. W., Heckman, G. R., Greer, M. S., and Smith, J. B.: 1988, Eos, Trans. AGU 69, 962.Google Scholar
  8. Howard, R.: 1977, in A. Bruzek and C. J. Durrant (eds.), Illustrated Glossary for Solar and Solar-Terrestrial Physics, D. Reidel Publ. Co., Dordrecht, Holland, p. 7.Google Scholar
  9. Kane, R. P.: 1978, Nature 274, 139.Google Scholar
  10. Kane, R. P.: 1987, Solar Phys. 108, 415.Google Scholar
  11. Langley, R.: 1971, Practical Statistics Simply Explained, revised ed., Dover Publ., Inc., New York.Google Scholar
  12. Lapin, L. L.: 1978, Statistics for Modern Business Decisions, second ed., Harcourt Brace Jovanovich, Inc., New York.Google Scholar
  13. Meadows, A. J.: 1970, Early Solar Physics, Pergamon Press, London.Google Scholar
  14. McKinnon, J. A.: 1987, Report UAG-95, World Data Center A, Boulder, Colorado.Google Scholar
  15. Ohl, A. I.: 1976, Soln. Dannye No. 9, 73.Google Scholar
  16. Ohl, A. I. and Ohl, G. I.: 1979, in R. F. Donnelly (ed.), Solar-Terrestrial Predictions Proceedings, NOAA Space Environment Laboratory, Boulder, Colorado, p. 258.Google Scholar
  17. Sargent, H. H., III: 1978, in Twenty-Eighth IEEE Vehicular Technology Conference, IEEE, Inc., New York, p. 490.Google Scholar
  18. Schove, D. J.: 1983, Sunspot Cycles, Hutchinson Ross Publ. Co., Stroudsburg, Pennsylvania.Google Scholar
  19. Schatten, K. H. and Sofia, S.: 1987, Geophys. Res. Letters 14, 632.Google Scholar
  20. Thompson, R.: 1988, J. Australian Phys. 25, 17.Google Scholar
  21. Waldmeier, M.: 1961, The Sunspot-Activity in the Years 1610–1960, Schulthess & Co., Zürich.Google Scholar
  22. Wilson, R. M.: 1984, NASA TP-2325, NASA Marshall Space Flight Center, Huntsville, Alabama.Google Scholar
  23. Wilson, R. M.: 1987, Solar Phys. 112, 1.Google Scholar
  24. Wilson, R. M.: 1988a, Solar Phys. 115, 397.Google Scholar
  25. Wilson, R. M.: 1988b, Geophys. Res. Letters 15, 125.Google Scholar
  26. Wilson, R. M.: 1988c, J. Geophys. Res. 93, 10011.Google Scholar
  27. Wilson, R. M.: 1988d, Solar Phys. 117, 179.Google Scholar
  28. Wilson, R. M.: 1988e, Nature 335, 773.Google Scholar

Copyright information

© Kluwer Academic Publishers 1990

Authors and Affiliations

  • Robert M. Wilson
    • 1
  1. 1.Space Science Laboratory, NASA Marshall Space Flight CenterHuntsvilleU.S.A.

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