I have to go with kiwistonewall. I take the heretical position that the main driver of the solar cycle is the Sun itself.
Maybe what we experience as the solar cycle is the result of the dynamics of pulsations in the fusion process in the core as it attempts to attain a steady-state reaction, generating the various fusion products in the course of those pulsations in the form of the heavier elements that may eventually reach the photosphere and possibly go beyond it into something we are able to detect here. That would mean that the origins of current cyclical activity are thousands if not millions of years of age and certainly not something caused by distant, recent planetary alignments. That would also place attempts to predict solar activity into the future in the realm of the reading of entrails, or peering into the innermost parts of the Sun, although I hear that will put your eyes out. :-)
Any two or more periodic events with different periods of occurrence will eventually coincide at some point in time over a long enough period. That doesn’t mean one is the cause of the other.
I say this not to denigrate in any way the work of many here, and I appreciate all their sincere efforts, but I will stick to my heresy.
All this is very well, and I am sure that the planets have an observable effect on the solar cycle, its length, shape etc.
But there is something else, far bigger that drives the grand maxima & minima. These may persist for 3-7 cycles.
If the planets were the only factor, then we would expect to see a much more regular pattern over the millennia, but we don't.
Instead, we see (over 1000's of years) large fluctuations in the sun. It is a variable star after all.
I remain a skeptic about the planets being the main driver of the sun's output.
There are very good reasons why we see fluctuations over the centuries, and is all to do with Jupiter and Saturn. Angular momentum varies for the same reason with N+U acting as the controller. In the last week there have been amazing discoveries matching angular momentum and the 11000 yr C14 graph. Way to big to discuss it all here, read my article here.
agree nobrainer With the three mechanisms all known solar cycle strengths and lenghts are absolutely logical and expected.
Regarding grand minima, there are several conditions that must fit, and also notice that planetray alignments never are the same (at least in our lifetime...) Another important condition for grand minima would be the fact that JuSa resonate with the tidal max every 100 years.
So there are two pretty fixed cycles of 100 and 172 years (JuSa vs VeEaJu, and UrNe). Then there are two "qualitative" cycles that can have various length. These would be two different definitions of a supercycle: -one is the time between SCs that have minimum around the Jupiter aphelion -the other would be the time between the ends of what I call the solar cycle "bullmarkets" (end of period of short and strong cycles, which is terminated by the tidal max cycle, and results in JuSa forced out of phase)
What I don´t yet have checked, is whether these qualitative supercycles of 150-200 years are regulated by the fixed cycles of 100 and 172 years, or if they are self-regulating within a fixed interval...
one thing that bothers me, is that the JuSa/2 cycle of 9,96 years is not symmetric in the SC data - or the conjuntion has a somewhat different respons as the opposition.
The other thing is that there is a drifting tendency in the preferred JuSa angle at minimum. At the Maunder minimum the solar cycle almost didn´t manage to get in phase with JuSa, while in the 1900s they all were in phase...
Could be because the JuSa cycle not quite resonates with the Ju: 19,86 x 3 = 59,58 and 11,86 x 5 = 59,3 or 19,86 x 9 = 178,74 and 11,86 x 15 = 177,9
So the JuSa-conjunctions drift relative to the Ju-perihelion for each supercycle of ~178 years (by 0,84 years)
After some 735-794 years the JuSa-conjunction is again close to the Jupiter perihelion. If this should result in 4 supercycles, the length would be on average 184-199 years.
In those supercycles where there are many JuSa conjunctions/oppositions close to Jupiter perihelion, could have grand minima potential.
seems like the pieces are falling into place again...
the short term struggle between Ju and JuSa, with VeEaJu as regulator also manifest itself on long term through a supercycle.
Every 188/2 +/-10 years the JuSa 9,93 year cycle resonate with the VeEaJu tidal max. This results in JuSa forced out of phase.
Every 166 +/-10 years the Ju 11,86 year cycle resonate with the VeEaJu tidal max, which results in Ju out of phase.
A supercycle can be defined as the period between every Ju-out-of-phase, or between every two JuSa-out of phase.
Some supercycles will have a tendency to have many SCs with JuSa in phase, and others with few in phase. The reason is that the JuSa-conjunctions are not stable relative to the Jupiter periehelion. This drifting results in a larger supercycle of around 800-1000 years.
In addition the positions of Uranus/Neptun can further amplify or dampen the solar cycle.
The implication, bigbud, of Ju/Sa/Ur/Np causing variable output in our Sun is that this should apply elsewhere. Every close star examined for the presence of planets shows them, and they are usually several sizes larger than our planets. Lets see, we have a count of 250 close by stars w/planets as of a year ago, and they just keep piling them on.
There must be a lot of variable stars out there in close that show similar patterns, and not just occultations.
the Fourier spectrum of monthly SSN seem to back up my hypothesis of the three cycles that regulate the solar cycle Jupiter-Saturn synodic 9,93 Venus-Earth-Jupiter tidal max 11,08 Jupiter sidereal 11,86
There is also a top around 100 years, which is the period for when the Jupiter-Saturn conjunctions/oppositions happen around VeEaJu tidal max (9x11,08 ~ 10x9,93) The JuSa and VeEaJu both seem to elevate SSN, while Ju dampens.
Would not whish to dampen your enthusiasm, spectrum analysis and power distribution of the SC sequence were done number of times before. For spectral analysis to be credible, a larger number of cycles is required. When you line up cycles according to their duration
you get a nearly even distribution from 10 to 11.5 years, then jump to 12.25 years and then even again to 12.6. It obstinately refuses to have a single cycle at or very near 11.86 years, as if it wishes to tell us that the sequence is not driven by Jupiter (unfortunately a frequently used argument against us ‘planetarists’). It is a thankless task but keep going.
I think I have an answer, but have to work on it first.
Notice that the tidal-max cycle of VeEaJu is the "strongest", as there always is sunspot activity at tidal max. This means that this cycle can either prolong decreasing SCs, or kickstart a new SC. So it is a strong regulator of the timing of SCs, and also influences the strength of the cycle.
Then there is the Jovian cycle that also has great influence on timing, as it favors minimum to be around +/- 45 deg to perihelion. But this tendency can be overruled by the tidal max, or modified when JuSa is in strong/weak phase.
The Jupiter-Saturn cycle of conjunctions and oppositions is the most important contributor to SC strength, best seen when the JuSa-cycle is in or out of phase relative to the solar cycle. The JuSa cycle also has the ability to prolong and kickstart, as long as it is allowed by the two other cycles...
------------- forecasting a coming SCs strength seem not to be the hardest task, but rather the timing of start and end need some more research
the three driving-cycles seen over time, when going in and out of phase with each other (simplified by fixed cycles).
The 11,08 year tidal-max cycle cannot be breached. Combined with the 11,86 year Jovian cycle, this results in a supercycle of average 168 years, or 15,2 solar cycles (14,2 Jovian).
Within this supercycle, the solar cycle must adapt to the three driving cycles. About every 96 years the tidal max cycle comes in conflict with the JuSa cycle. This results in JuSa falling out of phase, and weak solar cycles. On average 1,75 such events in each supercycle. The JuSa cycle combined with the Jovian has a longer term cycle of about 425 years. The result should be that the 168-year cycles have different capability to make the solar cycle to be in phase with JuSa. Which again means some supercycles will have more weak cycles than others.
When looking for solar cycle to have a duration of the Jovian cycle 11,86, one must look for:
-A solar cycle with minimum in the AB-interval, most likely B -A solar cycle that is not to close and influenced by the tidal/JuSa-conflict which normally is a couple SCs after the minima have entered the AB-interval, and marks what I call the end of "solar cycle bull-market". -A solar cycle that is out of phase with JuSa, which is a solar cycle where Jupiter-Saturn conjunction/opposition happens near the solar minimum or in the rising phase of the solar cycle.
Then I find: SC-8 (B) 11,0 yr SC-6 (A) 10,0 yr SC-5 (B) 8,5 yr SC-3 (B) 11,5 yr -Jovian! SC12 (B) 10,7 yr SC13 (B) 12,1 yr - Jovian! SC14 (B) 11,9 yr - Jovian!
In addition, two more cycles are Jovian, all though they are in phase with JuSa: SC11 (B) 11,7 yr - Jovian! SC20 (A) 11,6 yr - Jovian!
now here is an explanation on how the planets regulate the solar cycle. So far it is based on intuition, so the formulations may be a little naive or inaccurate.
First it is the effect of the solarsystem center of mass or barycenter. Here I simplify and divide into two effects: one by Jupiter´s distance to Sun, and one by the Jupiter-Saturn angle.
Jupiter distance Jupiter´s orbit is elliptical, and maximum distance differ by 10% to minimum distance. When Jupiter moves away from the Sun, the center of mass moves away from the Sun creating a greater pull, which stimulates the "solar dynamo" and winds up energy. Therefore the sunspot activity is rising when Jupiter is moving fast away from the Sun
Jupiter-Saturn angle When Jupiter and Saturn are conjunct or opposite, the barycenter moves slowly around the Sun. When Jupiter-Saturn are at right angles the barycenter moves quickly around the Sun, creating a greater pull on the sun, and on the "solar dynamo" that winds up energy. Therefore solar activity should be rising when Jupiter-Saturn are at right angles, and decreasing when they are conjunct/opposite
Finally there is the mechanism of tidal waves caused by the tidal planets Jupiter, Venus and Earth. These tidal waves happen all the time, but the planets are most favorable aligned every 11,08 years, creating specially strong tidal waves. The tidal waves disturb the upper layers of the Sun, provoking sunspots to create and erupt. In this way the built up energy is forced to be released. When the solar cycle is very much out of phase with the tidal-cycle, we can see solar cycles being forced to prolong (like now in SC23), or being kickstarted from minimum even when the barycenter mechanisms do not generate much energy.
Sounds plausible? edit: definitely some flaws in the physics in my model - must work on it...
Further, the Jupiter-Saturn angle also makes the barycenter move towards and away from the Sun, all though not as quickly (?) as the from the Jupiter distance effect. Before a Jupiter-Saturn conjunction the barycenter moves away from the Sun, and after an opposition. That means that the JuSa-effect is not symmetrical (one thing that I earlier have mentioned, and that disturbed me... but now I know why...)
For SC24 it doesn´t look any good: Jupiter is moving towards periehlion, and getting closer to the Sun. Jupiter-Saturn are approaching opposition. The tidal-max around 2003-2005 overkilled the solar dynamo, which now isn´t getting any help from Ju or JuSa. And we are close to tidal-minimum. Some partial lineups of VeEaJu may spark some sunspots, but it doesn´t look any good for 2009...
well, it is still about a year until tidal-minimum and from Jupiter-Saturn we see no help for a long time. But the Jupiter cycle favor solar minimum around angle 320-330 deg, which is around July09-Jan10.
Also a possible interval around summer 2008 (looks unlikely) and one around summer 2011 (too late after first sunspot?).
The first SC24 sunspot was Jan 08, and solar minimum is often 12-24 months after the first spot? In this case I think it will be in the later end.