The Solar Flux and Sunspot Number; A Long-Trend Analysis

  • Babu Ram Tiwari Chinese Academy of Sciences, Beijing
  • Mukul Kumar State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing


We investigate the nature of monthly sunspot numbers and solar flux F10.7 by employing the linear and multiple regression techniques. We observed a brilliant correlation between monthly mean sunspot number and F10.7. We observed that even in deep solar minimum there exist some magnetic activities. We obtained the coefficient of determination R2 to be 0.9533. We estimated the correlation coefficient for solar flux F10.7 and sunspot number to be 0.97. We extrapolated the F10.7 back to the year 1700 and observed a good correspondence between the modelled F10.7 and sunspot nature. We also found a very good correspondence between the modelled and observed solar flux F10.7.

Keywords: Sunspots, Solar cycle, Solar Flux


Download data is not yet available.


  • Bray R. J., Laughhead R.E., Sunspots, The International Astrophysics Series, London: Chapman & Hall, 1964.

  • Cowling T. G., The growth and decay of the sunspot magnetic field, MNRAS, 1946, 106.

  • Alfven H., On the theory of sunspots, Tellus, 8:2 1956.

  • Parker E. N., Hydromagnetic Dynamo Models, The Astrophysical Journal, 1955, 122, 293.

  • Babcock H. W., The topology of the Sun's magnetic field and the 22-year cycle, The Astrophysical Journal, 1961, 133, 572.

  • Leighton R. B., Transport of magnetic fields on the Sun, The Astrophysical Journal, 1964, 140, 1547.

  • Zirin H., Fine Structure of Solar Magnetic Field, Solar Physics, 1972, 22, 34-48.

  • Meyer F., Schmidt H. U., Weiss N. O., Wilson P. R., “The growth and decay of Sunspots”, MNRAS, 1974, 169, 35-57.

  • Southworth G. C., Microwave radiation from the Sun, J. Franklin Inst., 1945, 239, 285-29.

  • Mordvinov A. V., Prediction of monthly mean values of solar activity index F2800 using a multiplicative autoregressive model, CoSka, 1986, 16, 617.

  • Dmitriev A, Minaeva Yu., Orlov Yu., Riazantseva M., Veselovsky I., Solar Activity Forecasting on 1999-2000 by means of artificial neural networks, Reported on EGS XXIV General Assembly, 1999.

  • Zhao J., Han Y. B., Historical dataset reconstruction and a prediction method of solar 10.7 cm radio flux, Chin.J. Astron.Astrophys., 2008, 8

  • Holland R. L., Vaughan W. W., Lagrangian least-square prediction of solar flux F10.7. 1984, 89, 11-16.

How to Cite
B. Tiwari and M. Kumar, “The Solar Flux and Sunspot Number; A Long-Trend Analysis”, Int. Ann. Sci., vol. 5, no. 1, pp. 47-51, Jul. 2018.
Research Article