Can Stochastic Resonance Explain Recurrence of Grand Minima?

DOI: 
10.3847/2041-8213/ac0fd6
Publication date: 
24/08/2021
Main author: 
Albert, Carlo
IAA authors: 
Ferriz-Mas, Antonio
Authors: 
Albert, Carlo;Ferriz-Mas, Antonio;Gaia, Filippo;Ulzega, Simone
Journal: 
The Astrophysical Journal
Publication type: 
Article
Volume: 
916
Pages: 
L9
Abstract: 
The amplitude of the 11 yr solar cycle is well known to be subject to long-term modulation, including sustained periods of very low activity known as Grand Minima. Stable long-period cycles found in proxies of solar activity have given new momentum to the debate about a possible influence of the tiny planetary tidal forcing. Here, we study the solar cycle by means of a simple zero-dimensional dynamo model, which includes a delay caused by meridional circulation as well as a quenching of the α-effect at toroidal magnetic fields exceeding an upper threshold. Fitting this model to the sunspot record, we find a set of parameters close to the bifurcation point at which two stable oscillatory modes emerge. One mode is a limit cycle resembling normal solar activity including a characteristic kink in the decaying limb of the cycle. The other mode is a weak sub-threshold cycle that could be interpreted as Grand Minimum activity. Adding noise to the model, we show that it exhibits Stochastic Resonance, which means that a weak external modulation can toss the dynamo back and forth between these two modes, whereby the periodicities of the modulation get strongly amplified.
Database: 
ADS
URL: 
https://ui.adsabs.harvard.edu/#abs/2021ApJ...916L...9A/abstract
ADS Bibcode: 
2021ApJ...916L...9A
Keywords: 
Solar dynamo;Solar cycle;2001;1487