In a recent publication in Space Science Reviews (2013), renowned solar scientists Ken McCracken, Juerg Beer, Friedhelm Steinhilber and Jose Abreu studied the solar minimums over the last 9300 years. Based on measurements of beryllium and carbon isotopes as indicators for the intensity of cosmic rays, which are modulated by solar activity, the scientists arrived at the result that the minimum of 2007 to 2009 had similar characteristics as the minimums occurring during the time of the Dalton Minimums of 1780 to 1820. They discovered a 208-year periodicity (Suess-de Vries) of a grand solar minimum in the past. Therefore they anticipate in the near future the events of a Dalton Minimum, but not a Maunder Minimum.
The paleo-cosmic ray records are used to study the properties of the heliosphere and solar processes over the past 9300 years. They show that both varied greatly over that time, ranging from ∼26 “Grand Minima” of duration 50–100 yr when the Sun was inactive, to periods similar to the past 50 years of strong solar activity. This shows that the detailed information regarding the heliosphere gained during the “space era” represents an extreme case, and is not representative of the majority of the past 9300 yr. The data confirm that the 11 and 22-year cycles of solar activity continued through the Spoerer and Maunder Grand Minima. Throughout the 9300 yr interval, “Grand Minima” usually occurred in groups of 2 to 4, similar to the group of four that occurred in the interval 1000–1800 AD. The groups are separated by ∼1000 yr intervals without Grand Minima. Frequency spectra of the full 9300 yr record show that the heliospheric and solar phenomena exhibit >10 well-defined and persistent periodicities. We speculate that the solar dynamo exhibits a 2300 yr periodicity, wherein it alternates between two different states of activity. In the first (∼800 yr duration) solar activity weakens greatly every 100–200 yr resulting in a sequence of Grand Minima, while in the other, the solar dynamo suffers smaller changes; the centenary scale solar and heliospheric changes are smaller, being similar to those that occurred in the interval 1890–1910. The paleo-cosmic ray evidence suggests that the Sun has now entered this more uniform period of activity, following the sequence of Grand Minima (Wolf, Spoerer, Maunder, and Dalton) that occurred between 1000 and 1800 AD.
There is a longer discussion of the issue at The No Tricks Zone, where the above introduction of this paper’s abstract was taken.
One thing for sure, we are on the cusp of a grand minimum. The open question is at what level, Dalton or Maunder. The work of Livingston and Penn would indicate it will be a Maunder. If a reader knows of an update by Livingston and Penn lets me know.