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arXiv · 2504.09144

Magnetic energies (and some other parameters) in solar active regions of different Hale and McIntosh classes: statistical analysis for 2010-2024

I. V. Zimovets·I. N. Sharykin·W. -Q. Gan
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Abstract

A statistical analysis of magnetic energies of the nonlinear force-free and potential fields, and their difference (a proxy for the free magnetic energy) in active regions (ARs) on the Sun of different Hale (Mount Wilson) and McIntosh classes for the period from May 1, 2010 to June 12, 2024 is presented. The magnetic fields in ARs are calculated using the GX Simulator based on the information about ARs contained in the daily Solar Region Summary (SRS) files provided by the NOAA SWPC and vector magnetograms by the Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics Observatory (SDO). Total unsigned and signed magnetic fluxes and vertical electric currents on the photosphere are also calculated. For the parameters considered, distributions have been determined in total for all ARs and separately for each Hale and McIntosh class. Minimum, maximum, mean values of the parameters and standard deviations were calculated for each class. The information about the parameters is presented in the form of graphs and tables. The magnetic energies, unsigned magnetic flux, unsigned vertical current, as well as the integral number of sunspots, number of ARs, and area of sunspots, integrated over ARs visible per day on the solar disk, exhibit similar approximately 11.6-year cyclicity. On average, magnetic energies of ARs increase with increasing Hale and McIntosh class, while the average fraction of the free magnetic energy in ARs of different classes differs weakly. We also found that the Poisson Flare Probabilities (PFPs) correlate with the parameters, and the Pearson correlation coefficient is up to 0.89. The results reveal relationships between various parameters of ARs and may be used in developing prediction of space weather effects.

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I. V. Zimovets, I. N. Sharykin, W. -Q. Gan. 2025-04-12. Magnetic energies (and some other parameters) in solar active regions of different Hale and McIntosh classes: statistical analysis for 2010-2024. https://arxiv.org/abs/2504.09144

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