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Following cycle 23 in real time :

In the page titled "my comments on these results", written in 1989, I added in october 1995 a forecast of sunspot numbers for the end of cycle 22 and cycle 23. I feel interesting to plot on the same page both this 1995 forecast (blue dots) and the actual value of sunspot numbers.

I use the SIDC monthly indexes, available on line. It must be noted that the last monthly values are premiminary results which can be changed later.

Remark (october 1995) : Could cycle 23 be of great amplitude ? It seems already that cycle 22 ends in advance, which could indicate a phase shift. Cycle 23 could start also in advance, and like for the situations encountered for cycles3 or 19 (fig 1), (fig 5), be of great amplitude. This effect could be reinforced by the fact that, since half a century (as Bracewell found it), "negative" cycles have a greater amplitude than"positive" cycles.
Remark (december 1997) : As stated in 1995, cycle 22 has ended in advance. Cycle 23 started also early. It seems that it does it not so much than the blue dotted pattern indicated : just a matter of about one year. The stop-start real line has an "S" bended curvature instead of the linear one plotted rapidly with eye and hand (blue dots). The start pattern looks a little like cycle 19 one. Could it have a very fast increase from index 50 to 130-150 in just one year (1998) ? Let's wait for the coming months to have a better view.
Remark (january 2000) : The increase of cycle 23 is on. It seems, for the moment, that the concavity of the red curve is directed downwards, though the end of 1999 (december) showed a decrease. It is likely already now that the prediction of 1995 (cycle peaking in 2000-2001 with a maximum above 200 is not the only possible scenario.
Different scenarii can be imagined :
- Maximum in 2000, index around 160-180
- Maximum in 2001, index around 180-200
- Rapid increase in 2000, to a level around or above 200 (see cycle 19).
The last one would be the more conformant to the law "start in advance => large maximum". Let's see later ;)
Remark (april 2001) : 2000 showed a moderate increase and the beginning of 2001 shows a decrease. If some strong events occur in 2001, cycle 23 could have a great amplitude, reaching it's peak in 2001/2002. But this seems rather unprobable and therefore, the cycle should be of normal (even low) amplitude with it's maximum taking place in 2000.
The figure, in this latest case, regarding the two curves (syzygies / Wolf numbers) seems not to have happened since the Wolf numbers are recorded.
Remark (july 2002) : A very interesting feature is going on. After a maximum, a decrease occured in 2001, which could induce to think that cycle 23 was on it's ending and that, globally, the solar cycle was escaping from the lock on the VeEaJu signal.
By the end of 2001 and beginning of 2002, activity increased again : the sunspots number curve is now fitting again the filtered syzygies curve. As can be seen, this last one hasn't reached it's maximum, and two strong VeEaJu cunjunctions must occur. We can imagine that cycle 23 will increase again in 2002-2004, or stay around a level of 150 for this time, and then decrease by 2005-2006.
The law "start in advance - great amplitude" is still very conjectural. The fitting of the sunspots cycle to the VeEaJu signal proves to be good on cycle 23 also !
Remark (september 2005) : Three VeEaJu cunjunctions provoqued three synchronized spikes on the signal, which pushed the curve towards the maximum. The decreasing of the cycle is therefore slow, and it's end will probably look like a classic cycle's end. The "start in advance" feature had no influence, neither on the amplitude of the cycle, nor on it's phase at the end. Obviously, my prediction of 1995 was good for the phase, bad for the amplitude :)
As explained on a page above, considering the bimodal distribution of the cycles length, and what happened on cycle 23, it seems more obvious that, in most cases, cycles are triggered by a Ve-Ea-Ju syzygie. This happens when the sign of the "quality function" changes, i.e. going from the Ve-Ea cunjunction to the Ve-Ea opposition situation when encountering the Ju longitude, modulo 180 degrees. Seen from the earth, the rule could be :

Solar cycles start when
  • Venus goes from a morning star to an evening star, or reverse.
  • Jupiter is hidden by the sun, or on the contrary, Jupiter is very bright, showing high in the sky in the middle of the night.

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