Solar Physics

, Volume 153, Issue 1–2, pp 445–448 | Cite as

Periodicities in Forbush decreases and solar activity

  • Probhas Raychaudhuri
Solar Physics Letters


We have studied Forbush decreases (FD) with solar flare data and major solar proton event (SPE) data (E > 10 MeV) for the years 1976–1986 and have found that FD solar flare data exhibit periods around 0.95, 2.4, and 4.75 years at >99% level of confidence (CL), while SPE data exhibit periods around 2.6 and 5.0 years (at >95% CL). Because of a common periodicity around 2.5 years, it is suggested that FD with the solar flare data and major SPE data, together with solar diameter and solar neutrino variations, behave similarly and may have a common origin.


Solar Activity Sunspot Number Solar Neutrino Forbush Decrease Solar Proton Event 
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Copyright information

© Kluwer Academic Publishers 1994

Authors and Affiliations

  • Probhas Raychaudhuri
    • 1
  1. 1.Department of Applied MathematicsCalcutta UniversityCalcuttaIndia

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