Journal of Physical Studies 23(1), Article 1903 [5 pages] (2019)
DOI: https://doi.org/10.30970/jps.23.1903

DYNAMICS OF THE FINE STRUCTURE OF THE 22-YEAR SOLAR ACTIVITY MAGNETIC CYCLE

M. M. Koval'chuk1, R. Ye. Rykaluk2, M. I. Stodilka1, O. A. Baran1, M. B. Hirnyak1

1Astronomical Observatory of the Ivan Franko National University of Lviv,
8, Kyryla i Mefodia St., Lviv, UA--79005, Ukraine
2Faculty of Applied Mathematics and Informatics of the Ivan Franko National University of Lviv,
1, Universytetska St., Lviv, UA--79000, Ukraine
Myroslav.Stodilka@lnu.edu.ua

An analysis of the dynamics of the fine structure of the 22-year cycle of solar activity (1964-1986) was carried out. The complete homogeneous data series for sunspot data such as Wolf numbers, squares of groups and individual spots, their coordinates, polarity and magnetic fluxes were retrieved from the electronic data base of Daily Solar Data.

Depending on the logarithm of the maximum areas of the spot groups, we divided them into two populations -- the large and small ones (hypothesis by Nagovitsyn, Pevtsov's {\em et al.}). They intersect in the domain lg\,$S=1.8-1.9$, where $S=60-90$ m.f.h. In this domain, the two populations of the spot groups are separated by the average lifetime takes place: less than 3-4 days -- for small and more than 4-5 days -- for large groups of spots. The two sunspot populations differ in the dynamics of the magnetic field distribution: the fields with a weak field strength (about 1600\,G) are localized in small spots, while the fields with a powerful flow -- in large spots, where magnetic field reaches 3000\,G. The analysis of the fine structure of the 22-year cycle confirmed the existence of the so-called points of the Waldmeier's fracture points on the growth branches, after which the sunspot production slows before the solar maximum. Comparison of the spot groups in the northern and southern hemispheres of the Sun shows the predominance of spottedness on the branches of growth in the northern hemisphere. So, a positive asymmetry dominates there, and, vice versa, on the recession branches, the negative asymmetry of the southern hemisphere starts to dominate. The asymmetry of the sunspots' magnetic field in the two hemispheres behaves in a similar way. The indexes of the magnetic asymmetry are maximal on the branches of growth till the maxima of the magnetic activity cycle, namely, during the periods of the sunspots' magnetic field polarity reversal.

PACS number(s): 96.60.qd

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