Monthly averages of the sunspot number visible on the sun, observed from 1749, Zurich Observatory, and from 1848 other observatories, have been analyzed. This time signal presents a frequency power spectra with a clear 1/fα behavior with α≃0.8±0.2. The well known cycle of approximately 11 years, clearly present in the spectrum, does not produce a sensible distortion of that behavior. The eventual characterization of the sunspot time series as a fractal is analyzed by means of the detrended fluctuation analysis. The jump size distribution of the signal is also studied.
@article{arxiv.nlin/0403032,
title = {Analysis of Sunspot Number Fluctuations},
author = {H. Fanchiotti and S. J. Sciutto and C. A. Garcia Canal and C. Hojvat},
journal= {arXiv preprint arXiv:nlin/0403032},
year = {2016}
}