The Gnevyshev-Ohl Rule and Two Sunspot Group Populations

Abstract

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.