Transformation of the characteristics of quasi-biennial oscillation in a new version of the series of Wolf (relative sunspot) numbers

Abstract

With the introduction from June 2015 of a new methodology for estimation of Wolf numbers W (or WSN — Wolf sunspot number), this series was corrected from January 1749 to May 2015, i.e. a new version of the series WSN was proposed. The greatest transformation affected the cycles of a statistically reliable part of the series (since, 1849), which was clearly reflected in their amplitude correction and, accordingly, in the long-period component of the series, determining the epoch of maximum/minimum solar activity. The quasi-biennial oscillations available in the solar magnetic field and in the total flux of its radiation also manifest themselves in a number of parameters of the Earth ionosphere and evaluation of their transformation degree is of high significance. This paper compares the characteristics of the frequency interval of the quasi-biennial oscillations of both versions of a series.