On the long-term secular increase in sunspot number

A two-parameter secular fit is extended to the sum of the monthly mean sunspot numbers over the entire cycle, R(sum), and the mean sunspot number for the cycle, R(mean). Both R(sum) and R(mean) are shown to be highly correlated with the maximum amplitude of the sunspot cycle, R(max). Application of the theory to cycle 22 indicates that the present cycle will have an R(max) of 74 + or - 49.0.