English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

An examination of the maximum yearly values of theconventional sunspot number <I>Rz</I> of all cycles revealed fluctuations of variousintervals in the high periodicity region (exceeding 11 years), namely 2cycles (Hale, 22 years), 3 cycles (TRC, three-cycle) and longer intervals. The2-cycle spacings had the smallest amplitudes. According to the G-O(Gnevyshev-Ohl) rule (Gnevyshev and Ohl, 1948), the even-numbered series ofthe maxima of annual mean Wolf sunspot numbers <I>Rz</I> are followed by higheramplitude odd-numbered series. Kopecky (1950) generalized this relationto annual mean Wolf numbers corresponding to equivalent phases of theadjacent even-odd 11-year cycles. Therefore, we would call it the G-O-K rule. For thedata of 28 cycles (cycle −4 to cycle 23), it was found that four pairs (~29%)from the fourteen even-odd pairs showed failure of the G-O-K rule. In the remaining ten pairs, the magnitudes of the odd cycleswere well-correlated with the magnitudes of the preceding even cycles, butit was impossible to tell whether it would be a normal pair following theG-O-K rule or a possible case of failure. A much stronger sequence was thethree-cycle sequence (TRC, low, high, higher). The 2-cycle oscillations wereembedded into the TRC until the G-O-K rule failures occurred as in cycle 23. Thepatterns of cycle 17 (low), 18 (high), 19 (higher); 20 (low), 21 (high), 22(higher) were noticed and used by Ahluwalia (1995, 1998) to predict a lowvalue for cycle 23, which was accurate. However, in the earlier data, thepreceding sequence (14, 15, 16) was rather uncertain, and beforethat for seven cycles (cycles 8-14), there were no TRC sequences at all.During the twelve cycles −4 to 7, there were only three isolated TRCsequences (one doubtful).  In view of this chequered history of TRC, it isdoubtful whether the present TRC pattern (cycles 17–23) would persist inthe near future. Spectral analysis showed that in the first half (cycles −4 to9), larger periodicities (reminiscent of the Gleissberg cycle of ~80years) prevailed. but in the latter half, periodicities were different(3-year cycle was predominant) and the matching was not good. In particular,the points for the recent cycles 21, 22 seemed to deviate considerably fromthe constructed series, thus introducing unreliability in predictions for thefuture by using extrapolation of periodicities

Prediction of solar cycle 24 based on the Gnevyshev-Ohl-Kopecky rule and the three-cycle periodicity scheme