Onset and termination of solar grand minima: predictions of a stochastic Babcock-Leighton dynamo
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, cilt.551, sa.3, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 551 Sayı: 3
- Basım Tarihi: 2026
- Doi Numarası: 10.1093/mnras/stag1482
- Dergi Adı: MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Aerospace Database, Applied Science & Technology Source, Compendex, INSPEC, zbMATH, Directory of Open Access Journals, Academic Search Ultimate (EBSCO), Technology Collection (ProQuest)
- Çanakkale Onsekiz Mart Üniversitesi Adresli: Evet
Özet
We provide the first analytical and numerical calculations of the joint onset/termination rate-duration relationship for stochastic Babcock-Leighton dynamo models, and compare them with the recently reported relation from seven Holocene grand minima (R-2 (onset) = 0 . 76 and R-term(2) = 0 . 95 ). We employ the standard amplitude-equation truncation of the stochastic dynamo near its Hopf bifurcation-a 1D Langevin equation for the cycle-amplitude envelope with multiplicative noise. By fixing the single-free parameter via simultaneous calibration against four independent Holocene observables, we integrate similar to 3 . 3 & times; 10(6) yr of Monte Carlo realizations. Two main results follow. First, the population rate-duration relation is a power law with slope-0.55 +/- 0 . 01 for both phases, with a small structural asymmetry in goodness of fit Delta R-pop(2) = 0 . 08 +/- 0 . 02 ; both are derived analytically from the Ornstein-Uhlenbeck escape statistics of the underlying Langevin equation and are insensitive to the model parameters. Second, the apparent asymmetry Delta R-2 ti 0 . 19 between onset and termination in the observed sample is dominated by small-sample statistical noise of a single-mechanism null at N = 7 , of which only similar to 0.08 is structural; both observed values lie within the predicted bootstrap distribution (p(onset) ti 0 . 34 and p(term) ti 0 . 05 , broadly robust to detector parameters and observational uncertainty). We predict that the apparent gap will relax toward similar to 0.08 as the high-resolution 14 C catalogue is extended, and that N ti 15 well-resolved terminations would suffice to distinguish the minimal stochastic null from a state-dependent threshold mechanism. The result supports the view that grand minima are stochastically forced excursions of a weakly non-linear dynamo near criticality.