Hemispheric asymmetry in the sunspot cycle as a nonextensive phenomenon

TL;DR

This study applies non-extensive statistical mechanics to analyze hemispheric asymmetry in sunspot cycles, revealing a semi-sinusoidal variation of the asymmetry parameter over the Hale cycle and suggesting its use as a diagnostic tool for solar dynamo behavior.

Contribution

It introduces a non-extensive statistical approach to quantify hemispheric asymmetry in sunspot activity and demonstrates its potential for understanding long-term solar variability.

Findings

The asymmetry index q(A) shows northern hemisphere dominance.

q(A) varies semi-sinusoidally with a 22-year period.

The approach offers a new perspective on solar dynamo diagnostics.

Abstract

The appearance of dark sunspots over the solar photosphere is not considered to be symmetric between the northern and southern hemispheres. Among the different conclusions obtained by several authors, we can point out that the North-South asymmetry is a real and systematic phenomenon and is not due to random variability. In the present work, we selected the sunspot area data of a sample of 13 solar cycles divided by hemisphere extracted from the Marshall Space Flight Centre (MSFC) database to investigate the behavior of probability distributions using an out-of-equilibrium statistical model a.k.a non-extensive statistical mechanics. Based on this statistical framework, we obtained that the non-extensive entropic parameter $q$ has a semi-sinusoidal variation with a period of $\sim$22 year (Hale cycle). Among the most important results, we can highlight that the asymmetry index $q(A)$ revealed the dominance of the northern hemisphere against the southern one. Thus, we concluded that the parameter $q(A)$ can be considered an effective measure for diagnosing long-term variations of the solar dynamo. Finally, our study opens a new approach to investigating solar variability from the nonextensive perspective.