The Gnevyshev-Ohl Rule and Two Sunspot Group Populations
This work continues the study of the two sunspot group populations' properties discovered earlier (Nagovitsyn et al., 2009; Nagovitsyn et al., 2012; Nagovitsyn et al., 2017; Nagovitsyn and Pevtsov, 2016; Nagovitsyn et al., 2018; Osipova and Nagovitsyn, 2017). The concepts of “static” indices (when each sunspot group included in statistics once, characterizing the performance of the dynamo process) and “dynamic” indices (regular, when all the days of the group’s existence are present in statistics, describing, in particular, the influence of solar activity on terrestrial processes and heliosphere) are introduced. For static indices, the well-known Gnevyshev-Ohl rule in various formulations is tested—MGO, AGO, and DGO (see Introduction). The main conclusion is that for the number of small short-living groups (SSG) the Gnevyshev-Ohl rule is accurate to the contrary, and such groups form a pair in a 22-year cycle—a single whole in a combination of an odd and subsequent even cycle, with the latter having a smaller value.
The reported study was funded by RFBR according to the research projects no. 16-02-00090 (Yu.A. Nagovitsyn) and no. 18-32-00555 (A.A. Osipova) and by research program no. 28 of the Presidium of Russian Academy of Sciences (Yu.A. Nagovitsyn and A.A. Osipova).
This work utilizes synoptic data from Royal Greenwich Observatory (RGO) and Kislovodsk Mountain Astronomical Station (KMAS). The authors thank RGO and KMAS teams for their open data policy.
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