Bulletin of Taras Shevchenko National University of Kyiv. Astronomy, no. 53, p. 52-55 (2016)

Statistical pecularities of 24th cycle of solar activity

V. Efimenko, PhD,
V. Lozitsky, DrSci
Astronomical Observatory of Taras Shevchenko National University of Kyiv

Abstract
Current 24th cycle of solar activity is anomalous if following aspects: 1) it had non-monotonous phase of grown, and on different times of this phase it demonstrated peculiarities of both middle and weak cycle, 2) peak of cycle was two-top, and second top was higher than first on about 15 units of averages Wolf’s number (in old classification) that is maximum value for all previous cycles, and 3) temporal interval between first and second maximums of cycle was 26 months that is second value from all 24 cycles. As to index of  integral distribution of sunspot diameters, it was found earlier that this index  α, in the average, equals about 6.0 for 7 previous cycles, in diameter range 50–90 Mm. New statistical analysis based on data for 2010–2015 allows to conclude that for 24th cycle α ≈ 5.8. Thus, dispersion of diameters of sunspots in 24th cycle is typical for majority of solar cycles.

Keywords
Sun, solar activity, sunspots, integral distribution for diameters of sunspots, statistical peculiarities of 24th cycle

References
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Lozitsky, V.G., Efimenko, V.M. 2014, Odessa Astronomical Publications, 27, 2, 90
Solanki, S.K.  2003, Astron. Astroph. Rev., 11, 153

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