It shows how the sunspot cycle drifts towards right (compared with the optimal/average behaviour), because the sunspot cycles are longer than 10 years. Each ~96 years (Gleissberg low) the sunspot cycle has driftet into critical limit, and we get a phase-failure. This typically is seen as a very long cycle (like SC23), and then typically two weak sunspotcycles (SC24+25 ?)
I think this pattern worked for the Maunder minimum as well, and will try to visualize this in another video. However I think there was an "iceberg-effect" in the Maunder, where only the extreme large sunspots were visible.
www.sibet.org/solar/jusa02.wmv Some comments on the video: Notice that SC 3 and 4 started very early, trying to cancel the drifting towards critical limit. However SC4 was extended by the 11 year cycle, causing SC5 to be out of phase.
Next failure at SC11 that was extended, causing SC12 to fall out of phase.
At the recent Gleissberg low we saw SC 22 and 23 just barely staying within the critical limit, before SC23 was extended and causing SC24 to be out of phase
the key for understanding the Maunder minimum probably lies in solar cycle -10 in the years around 1634-1646
At a Gleissberg-low we normally see a couple short solar cycles, that shoot up steep from previous low (like SC 3, or SC 10, or SC 21 and 22). Then a prolonged solar cycle that causes a phase-failure in the next one, like SC-12, SC4, SC11 and SC23.
But ahead of the Maunder minimum we get another prolonged cycle, the SC-10. Just as if there was another Gleissberg-low shortly after the previous one.
So the "problem" is the prolongation and sunspot-activity around year 1943-44. The planetary cycles should have the explaination why this happened, but so far I havent quite found it.
And so it seems that two such "enter-the-Gleissberg" cycles number -12 and -10 was simply "too much for the solar dynamo and shutting it down".
Another clue is in the barycenter motion, that is disturbed by Uranus-Neptun in the years 1647-1653. So the prolonged SC-10 caused the SC-9 to happen in this unfavorable period. Again the planetary cycle should explain why this happened...allthough it seems an unfavorbale situation, it must have been the favorable outcome from the planetary cycles.
So the clue seems to be the period around years 1643-44. Why did we get a prolonged cycle? And why did the very similar situation in SC 6 to 7 have a different outcome?
that Maunder is still a puzzle. Not sure the SC-10 provides the key.
here is the cycle perspective: we have the short term cycles of 10, 11 and 12 years. The 11 year cycle is rigid and overrides the others. The three cycles produce beats of 10+11=96 years (and 2x96=192) 11+12=168 years 10+12=61 years (and 3x61=183) And finally we have the Uranus-Neptun cycle of 172 years that normally produce two or three disturbances, separated by ~40 years
So every ~96 years the short 10 year cycle has to surrender to the 11 year cycle. That causes the phase-failure and a Gleissberg low, easily seen as weak sunspot cycles.
And every ~168 years the 12 year cycle has to surrender to the 11 year cycle, which is not so easily seen in the sunspot cycles (normally results in stronger sunspot cycle)
And the 10 and 12 year cycle fights each other and one of them surrender each ~61 years. -either the 10 year cycle, which results in a Gleissberg low -or the 12 year cycle And the 10 year cycle surrenders near twice as often as the 12 year cycle
So the actual Gleissberg low is often somewhat shifted in time, depending on where the 61 year cycle is. last centuries these cycles have produced pairs of Gleissberg lows (or cycles). And every second cycle (high) is strong/weak (and long/short)
Then we have the grand minima. When we have the right configuration with regards to the two other cycles (168 and 172) we get a grand minima.
The grand minima seems to be a possibility at the first Gleissberg low of the pair (like 1640, 1820 and 2005) AND the first Gleissberg low has to happen at the "correct" interval of the 168 year cycle, and probably at the first of the three disturbances in from Uranus-Neptun in the 172 year cycle (phew)
---------- OK The first Gleissberg in Maunder obviously fulfilled this criterias (and the first UrNe-disturbance was in 1610) I also assume that the Spörer and Wolf-minima fullfilled these criterias.
Spörer: I go back 2x60 years from 1580 and get year 1460. That should be the first Gleissberg. But 60 years earlier is year 1400. And I go back 2x96 years from 1600 and get year 1408. So did the Gleissberg happen near year 1400 or 1460? The 168 year cycle had to be right. 1645-1460=185 years 1645-1400=245 years There were only two big disturbances from UrNe, around year 1470 and 1510
So the probable time for a grand minimum seems to be in the years around 1460 to 1520. And it may start a bit earlier and end a bit later.
Wolf: I begin at the other end this time. The UrNe disturbances were around years 1290, 1325 and 1360 (weak disturbance). 2x168 years earlier than 1645 is 1309 So we could look for grand minima setup around years 1290-1360 1400-60=1340, and 1340-60=1280 1408-96=1312 So this setup is different, because we have only one Gleissberg and not a pair.
---------- The Dalton: 1645+168=1813 The Ur-Ne disturbances in years 1790, 1830 and 1870 (weak) A Gleissberg in ~1790-1820. This looks very much like a grand minimum setup, but it didnt materialize. Sunspotcycle number 7 shot up just ahead of the disturbance, while SC-9 didnt make it.
-------- Now: 1813+168=1981 The UrNe disturbances are in years 1970 and 2010 A Gleissberg around year 2005 and the next in 2065 This doesnt look like an ideal grand minimum setup. We are a bit too late in the 168 year cycle, meaning that the two tidal cycles of 11 and 12 years are in phase (prevensts grand minima?) And we are at the second UrNe disturbance (a very weak on in years 2045)
But we do seem to have two narrow spaced Gleissberg lows, and should anyway have (mostly) weak sunspot cycles in the years 2010-2080
We do have pretty good knowledge of two setups (Maunder and Dalton), where only one of them produced a grand minima. By analysing these two setups I may find some clues for a better understanding of what triggers the catastrophe/grand minima...
When looking for a grand minima I think we must evaluate how a Gleissberg-low behaves. The cycles will give us some indications/probabilities. I think it is a question of whether the Gleissberg low manages to "slow down the sun below a threshold" and thereby create the "catastrophe"
And a clue seems to be very long solar cycles. Solar cycles -12, -11 and -10 were all very long lasting SC-12 max was around 4,5 years ahead of the tidal max (11yr cycle), the SC-11 was 2,5 years ahead and SC-10 max was close to tidal max. So we had a big slowdown over two SCs, that perhaps was a hint of catastrophe at SC-9
SC4 was around 6 years ahead of tidal max (extreme), the SC5 was close to tidal max, and so was SC6. So also here we had a severe slowdown, but all happend at the first cycle.
SC23 was near 4 years ahead of tidal max, and for SC24 the tidal max is at July 2014. The critical clue will be the date for SC25 max, relative to the tidal max at January 2026. So if we get a late SC24 minimum, and more slowdown in SC25... it may be a grand minimum setup after all...
thank you sigurdur my perspective on climate would be this:
I think the sun has two modes: -normal -grand minimum
In the normal mode we regulary get the Gleissberg lows (each ~96 years), and a Gleissberg low can potentially trigger a grand minimum. And I think the normal mode mostly stays normal, so I dont think the sunspot cycles were unusual strong in the 20th century (similar to what Leif is saying).
BUT we have had an unusual long Gleissberg cycle since the previous low around year 1880-1910 (which was a mild Gleissberg low). So if we make a moving 100 year average of sunspots, it will be higher than usual... and could explain some climate change.
But as Tilmari said: the short cycles in the 20th century has given the Sun a debt that has to be paid - meaning that the unusual long Gleissberg cycle will be followed by a very short one. So a Gleissberg low here around years 2010-2030, and the next one around 2065-2085 perhaps. (and a grand minimum in between cant be ruled out)
sigurdur so you have interest in markets? That is actually my profession - stockmarket trader and cycles are my speciality... Right now were are close to a sunspotcycle maximum, so market weakness soon is expected, usually over an extended period. But seems to be too early still, and looking for markets trending up to March-April. First we have to pass a cycle low around Nov 20 (another potential low around new year)