A preliminary low-dimensional chaotic analysis of the solar cycle

In this work we study the temporal characteristics of the solar cycle, expressed by the mean monthly sunspot index for a period of 235 years. The techniques of chaotic dynamics are used. We give preliminary results which support the hypothesis of chaotic dynamics and the existence of a low-dimensional strange attractor. In particular, we estimate the correlation dimension (≃4.5) and the largest Lyapunov exponent (0.15 bits/month). We also try to compare our results with the pseudochaotic profile of a purely stochastic Brownian process