Published online by Cambridge University Press: 27 November 2018
Solar activity is a chaotic process and there are various approximations to forecast its long term and short term variations. But there is no prediction method that predicts the solar activity exactly. In this study, a nonlinear prediction approach was applied to international sunspot numbers and performance of predictions was tested for the last 5 solar cycles. These predictions are in good agreement with observed values of the tested solar cycles. According to these results, end of cycle 24 is expected at February, 2020 with 7.7 smoothed monthly mean sunspot number and maximum of cyle 25 is expected at May, 2024 with 119.6 smoothed monthly mean sunspot number.