Modeling the grand minima of solar activity using a flux transport dynamo model

Karak Bidya Binay, bidya_karak@physics.iisc.ernet.in, Indian Institute of Science, India
Choudhuri Arnab Rai, arnab@physics.iisc.ernet.in, Indian Institute of Science

Abstract
One of the most striking aspects of the 11-year sunspot cycle is that there have been times in the past when some cycles went missing. A most well-known example of this is the Maunder minimum during 1645--1715. Analyses of cosmogenic isotopes (C14 and Be10) indicate that there were about 27 grand minima in the last 11,000 yr. This implies that about 2.7 of the solar cycles had conditions appropriate for forcing the Sun into grand minima. We address the question how grand minima are produced and specifically calculate the frequency of occurrence of grand minima from a theoretical model. With reasonable assumptions we show that our flux transport dynamo model leads to the conclusion that about 1--4% of the sunspot cycles may have conditions suitable for inducing grand minima.