Analysis of Sunspot Number Fluctuations

H.FANCHIOTTI, C.A.GARCÍA CANAL, C.HOJVAT, S.J.SCIUTTO

Fractals

World Scientific

Lugar: Singapore; Año: 2004 vol. 12 p. 405 - 411

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 $1/f^\alpha$ behavior with $\alpha\simeq 0.8 \pm 0.2$. 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.