Volume 88, Number 1, October 2009
Article Number 19001
Number of page(s) 6
Section Geophysics, Astronomy and Astrophysics
Published online 16 October 2009
EPL, 88 (2009) 19001
DOI: 10.1209/0295-5075/88/19001

Nonextensivity in the solar magnetic activity during the increasing phase of solar cycle 23

D. B. de Freitas and J. R. De Medeiros

Departamento de Física, Universidade Federal do Rio Grande do Norte - 59072-970 Natal, RN, Brazil

received 8 July 2009; accepted in final form 16 September 2009; published October 2009
published online 16 October 2009

In this paper we analyze the behavior of the daily Sunspot Number (SN) from the Sunspot Index Data Center (SIDC), the mean Magnetic-Field (MF) strength from the National Solar Observatory/Kitt Peak (NSO/KP) and Total Solar Irradiance (TSI) means from Virgo/SoHO, in the context of the q-Triplet which emerges within nonextensive statistical mechanics. Distributions for the mean solar Magnetic Field show two different behaviors, with a q-Gaussian for scales of 1 to 16 days and a Gaussian for scales longer than 32 days. The latter corresponds to an equilibrium state. Distributions for Total Solar Irradiance also show two different behaviors (approximately Gaussian) for scales of 128 days and longer, consistent with statistical equilibrium and q-Gaussian for scales < 128 days. Distributions for the Sunspot Number show a q-Gaussian independent of timescales, consistent with a nonequilibrium state. The values obtained (“q-Triplet” $\equiv$ $\{$ qstat, qsen, qrel$\}$) demonstrate that the Gaussian or q-Gaussian behavior of the aforementioned data depends significantly on timescales. These results point to a strong multifractal behavior of the dataset analyzed, with the multifractal level decreasing from Sunspot Number to Total Solar Irradiance. In addition, we found a numerically satisfied dual relation between qstat and qsen.

96.60.-j - Solar physics.
97.10.Jb - Stellar activity.
05.90.+m - Other topics in statistical physics, thermodynamics, and nonlinear dynamical systems.

© EPLA 2009