A lot of people know that our Sun goes into a regular maximum and minimum period. A few more can even tell you about the length of that cycle, which covers the usual maximum and minimum’s time. This time takes roughly 11 years.
But how many know that within the “regular” 11-year cycle, a shadowy, longer cycle of a basically weaker (alternately stronger) cycle could be ongoing in and around this “usual” cycle, as well?
My recent book on the subject (Grand Phases On The Sun by Steven Haywood Yaskell, Trafford: 2013) involves some of the most provocative solar science research in a long time on the matter. Dr. Cornelis de Jager of the Netherlands has come across what he and colleagues believe to be somewhat predictable patterns in long-term – and even shorter term – solar behavior.
The re-analysis of cyclic solar entities – using combed proxy data since the 1600s all the way to the most recent satellite data – yielded interesting results. Here de Jager joined forces with M. Lockwood of the USA and Russians like Yu A. Nagovitsyn to obtain a newer picture of the last 300 or so years of grand solar minima and maxima.
Due to transitional points of the so-called Gleissberg c. 80-year cycle covered by unstable solar tachoclinic interruptions in the basically stable if inert solar core motion (Gleissberg inertial motion) the Sun’s boundary conditions vary wildly at times. Indeed, the Sun is what de Jager terms “an unstable, nonlinear open boundary system.” This is a good way of describing a nuclear fusion-tempered entity. Only it is c. 800,000 miles in quasi diameter! The 11-year cycle most people might know -called the Schwabe- actually has a “magnetic component” called the Hale (22-year) Cycle which is routinely shaken by the thin but powerful surface-bound tachocline. In a complex dance of quasi-harmonic Hale episodes interlinked with Gleissberg transitions, due most likely to internal solar nuclear force it is thought (from the data, math, and observations) that the Sun jerks itself occasionally into deeper phase minima and maxima. These deeper phases (the cooler one often called an “episode”) are superimposed over the “usual” 11-year cycles.
So within the “champagne” of regular solar 11-year ins and outs of brightness (many solar spots and higher activity) and dimness (less spots, less activity) the Sun could already be spun out, so to speak, into a higher (grand maxima) or lower (grand minima) spin. In other words, you might have a “regular” series of up and down Schwabe Cycles going through a fairly usual dance, only to be dominated, as it were, by an existing grand maximum or minimum.
This has been the case, according to de Jager, with our Sun in some sort of “Modern Maximum” since 1924 till c. 2008 or 2009 or so. How long do extended maxima or minima go on? This is unknown. But judging by the re-combed data, some grand (or, extended) maxima can go on for hundreds of years. A cursory inspection of the updated data makes it look like from 80-200 years. But this is just a guess. The same applies to extended, or grand, minima (grand “episodes.”)
In a curious twist of events, minimums such as the “Dalton Minimum” (of from c. 1795-1816?) do not fit into “grand episode” categories, given the data and math. (In a probable parallel fashion, short maximas a bit longer than 22 years can also be excised from “grand phase” status.). The combed data shows the Dalton to be out of synch with the complex tachocline-core chaotic/stable dance sketched above.
Interestingly still, the last bona-fide grand minima of any repute (the Oort, Wolf, Sporer, and Maunder Minimums) all fit snug as a bug in a rug with any manifestation of what is called the Hallstatt Cycle’s (c. 2,500 years) negative phase – the last apparition of which having ended in 1935.
So if we do have any approaching solar minima ahead of us, perhaps they will all be far less than a half century (more like a quarter) in length for the next thousand years or so. We have been in a positive version of the Hallstatt since the 1930s. We have a long time ahead of us until the next negative phase. (The Hallstatt’s kind of like a long-term “Earth” cycle connected with the Sun.)
Perhaps deep cooling such as that experienced in the 1500s and 1600s won’t bother us for a long, long time to come, then.
However, if you read my book, maybe not.
Even degraded hemispheric cooling reminiscent of what the world went through during the Napoleonic Wars (in the Dalton) could anger, starve, and confuse an Earth population six orders of magnitude larger than the globe Bonaparte treaded upon. That we are currently coming down off a relatively drawn out extended maximum could be benefitting us in this curiously inactive solar time we are entering as of this writing. Trace CO2 and water vapor solar-generated from that time, as well as human “heat islands” which produce much of the same, could be keeping us artificially warm.
Let’s hope that all of this is indeed the case.
-Steven Haywood Yaskell (co-author, The Maunder Minimum and the Variable Sun-earth Connection, WSP: 2004)