Articles | Volume 17, issue 5
Ann. Geophys., 17, 639–641, 1999
https://doi.org/10.1007/s00585-999-0639-7

Special issue: Solar System Plasmas

Ann. Geophys., 17, 639–641, 1999
https://doi.org/10.1007/s00585-999-0639-7

  31 May 1999

31 May 1999

A straightforward estimation of the maximum sunspot number for cycle 23

B. Mendoza and J. Ramírez B. Mendoza and J. Ramírez
  • Insituto de Geofisica UNAM, Ciudad Universitaria, 04510 México D.F., MEXICO
  • E-mail: blanca@tonatiuh.igeofcu.unam.mx

Abstract. 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)

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