Forecast of an exceptionally large even‐numbered solar cycle

Abstract

Using the "dynamo theory" method to predict solar activity, an accurate prediction was made for solar cycle 21 by Schatten, Scherrer, Svalgaard, and Wilcox [1978]. The method had been first tested with data from 8 solar cycles. Using the same dynamo technique for solar cycle 22, a value for the smoothed sunspot number of 170 ± 25 is obtained. This large sunspot number is expected to peak in 1990 ± 1 year. The F10.7 radio flux is expected to reach a smoothed value of 210 ± 25 flux units. Since this value is larger than values obtained with prediction schemes based upon "statistical" and "periodicity" methods, it provides a useful test for the current methodology, based upon the strength of the Sun's polar field near solar minimum. The predicted degree of solar activity is expected to enhance the density and temperature of the earth's thermosphere to values somewhat larger than those found in solar cycle 21. This will have an impact on the orbital lifetime of low altitude satellites.