Abstract
A method to predict the amplitude and date of the maximum sunspot number is introduced. The regression analysis of the relationship between the variation rate of monthly sunspot numbers in the initial stage of solar cycles and both of the maximum and the time-length of ascending period of the cycle showed that they are closely correlative. In general, the maximum will be larger and the ascending period will be shorter when the rate is larger. The rate of sunspot numbers in the initial 2 years of the 23rd cycle is thus analyzed based on these grounds and the maximum of the cycle is predicted. For the smoothed monthly sunspot numbers, the maximum will be about 139.2 ±18.8 and the time-length of ascending period will be about 3.31±0.42 years, that is to say, the maximum will appear around the spring of the year 2000. For the mean monthly ones, the maximum will be near 170.1±22.9 and the time-length of ascending period will be about 3.42 ±0.46 years, that is to say, the appearing date of the maximum will be later.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Herman, J. R., Goldberg, R. A., Sun, Weather and Climate, Washington: NASA, 1978.
Obridko, V., Belov, A., Rivin, Y., The main features of solar cycle 22 and some forecasts of cycle 23, in Proc. of Workshop on Solar-Terrestrial Prediction (ed. Hruska, J.Y.), Ottawa: NOAA, USA, 1992, 261.
Thompson, R. J., A technique for predicting the amplitude of the solar cycle, Solar Physics, 1993, 148: 383.
Wang Jialong, Zhang Guiqing, On the progress of long-term and medium-term solar activity predictions, Progress in Geophysics, 1994, 9(Suppl.): 1.
Han Yanben, Wang Jialong, Preliminary verification of sunspot predictions of cycle 23 by the method of similar cycles, Chinese Astronomy & Astrophysics, 1999, 23: 139.
Zhang Guiqing, How strong is solar cycle 23? Acta Astrophysica Sinica, 1999, 19(2): 227.
Coffey, H. E., Solar-Geophysical Data Prompt Reports, 1999, 655: 26.
Author information
Authors and Affiliations
About this article
Cite this article
Han, Y. A method to predict amplitude and date of maximum sunspot number. Chin.Sci.Bull. 45, 1287–1290 (2000). https://doi.org/10.1007/BF03182904
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF03182904