Annales Geophysicae (May 1999)

A straightforward estimation of the maximum sunspot number for cycle 23

  • B. Mendoza,
  • B. Mendoza,
  • J. Ramírez

DOI
https://doi.org/10.1007/s00585-999-0639-7
Journal volume & issue
Vol. 17
pp. 639 – 641

Abstract

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Using the annual number of geomagnetically quiet days (aa < 20 γ) for the year after the solar minimum, this precursor method predicts that the maximum sunspot number for cycle 23 will be 140 ± 32, indicating that cycle 23 will be similar to cycles 21 and 22.Key words. Solar physics · astrophysics and astronomy (magnetic fields; general)