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Sunspot number time series: Exponential fitting and solar behavior

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The annual mean sunspot number time series for the period 1700–1990 A.D. was examined for possible fitting with exponential functions of the form N=NO.exp(Kt) for each phase, where the values of K, analogous to probabilities, are positive for the rising phase and negative for the declining phase. The results obtained suggest the participation of physical processes following macroscopic laws similar to those of explosion or nuclear divergence for sunspot production and of nuclear decay for sunspot disappearance.

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  • Kane, R. P. and Trivedi, N. B.:1991, Pageoph. 135, 463.

    Google Scholar 

  • MacDonald, G. J.:1989, Rev. Geophys. 27, 449.

    Google Scholar 

  • Mundt, M. D., Maguire II, W. B., and Chase, R. R. P.:1991, J. Geophys. Res. 96-A2, 1705.

    Google Scholar 

  • Pasricha, P. K., Aggarwal, S., and Reddy, M.:1991, Ann. Geophysicae, 9, 696.

    Google Scholar 

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Nordemann, D.J.R. Sunspot number time series: Exponential fitting and solar behavior. Sol Phys 141, 199–202 (1992).

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