Leif Svalgaard writes in with a collection of points on the 10.7 cm solar radio flux. Being busy tonight, I’m happy to oblige posting them. – Anthony
Leif writes:
People often call out that F10.7 flux has now reached a new low, and that a Grand minimum is imminent.
Perhaps this graph would calm nerves a bit:
The blue curve is the current F10.7 flux [adjusted to 1 AU, of course] and the red curve is F10.7 back at the 1954 minimum. The D spike (in 1954) was due to an old cycle [18] region.
There is always the problem of how to align two such curves.. These two were aligned by eye to convey the general nature of the flux over a minimum. The peaks labeled B and C and the low part A were arbitrarily aligned, because peaks often influence the flux for several weeks so would form natural points of correspondence. The detailed similarity is, of course, of no significance. Note, however that because of the 27-day recurrence one some peaks are aligned others will be too. again, this has no further [deeper] significance. The next solar cycle is predicted to be quite low and the cycle following the 1954 minimum was one of the largest recorded. We will, of course, with excitement watch how the blue curve will fare over the next year or so, to see how the ‘ramp up’ will compare to the steep ramp up in 1955-1956.
Of course, as there was more activity before and after the minimum and even during [as cycles overlap]. For the very year of the minimum apart from the spike at D there is very little difference. The important issue [for me] is the absolute level, because that is a measure of the density and temperature of the lower corona, generated by the ‘network’ or background magnetic field, which seems very constant from minimum to minimum, and certainly does not portend an imminent Grand Minimum, which is not to say that such could not come, just that a low F10.7 is not an indicator for it.
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vukcevic (00:29:28) :
Experts do not agree, but you may find some answers here:
http://www.vukcevic.co.uk/ links solar current, and solar subcycle
How is your comparison between observed and calculated times of solar maxima coming? You formula predicts a constant cycle length of 10.81 [except every century or so, when your polar fields do not reverse].
There are 3 odd cycles SC 6, 13, (SC23 is going to be one), longer than 12 years. If you remove SC6&13, then average length is 10.833, against 10.81 in my formula, which is closer than many other estimates. If I got it all correct, you would still dispute it, but even if you did not, lets face it, it would not be a candidate for the Astronomy’s award of the year. Thanks for the encouragement.
I am idling away my time on ‘climate change’ project at the moment, and since there is no mention of TSI, Sun, solar or SC, and making good progress, I may need some help there, if you are so inclined.
As far as reversals are concerned, I know about that anomaly in the formula, but now you brought it up, it did occur to me that the Livingstone-Penn effect might be a precursor to such an event (if you follow logic of it), which for some reason, may happen from time to time. If so than it reversal would be missed at SC24-25 transition around 2025, and remember you first heard it here.
What do you think the exit from the L-P effect may be?
vukcevic (00:24:06) :
There are 3 odd cycles SC 6, 13, (SC23 is going to be one), longer than 12 years. If you remove SC6&13, then average length is 10.833, against 10.81 in my formula, which is closer than many other estimates.
Omitting what doesn’t fit will always improve things. But you miss the point, namely that your formula predicts a constant length and the real lengths vary considerably.
Leif Svalgaard (04:31:03) :
Omitting what doesn’t fit will always improve things. But you miss the point, namely that your formula predicts a constant length and the real lengths vary considerably.
Of course, I know they do. I did say I am not competing for the for the Astronomy’s award of the year. I would prefer, if instead of stating obvious you might speculate about the L-P effect.
Since it appears that you have been giving more than passing attention to my formula (I am flattered ! ), you may have noticed that actually it does cross zero, but for such short time that actual SC25 would be insignificant (appearance of a long minimum), the Sun going early into SC26 which of course has same polarity as SC24.
Alternatively, if next set of PF is 50% lower (as the current is) than SC25 might be about 30-35, so not many SS would occur, and they may be hardly visible (LP). In such circumstances, whatever induces Hale cycle changeover may be so week and unable to completely flip the dynamo (complete process usually takes a year +), so hey presto we may not have polarity change.
vukcevic (06:33:53) :
I did say I am not competing for the for the Astronomy’s award of the year.
But you did claim that your formula had predictive power, which it obviously with a fixed period does not.
Since it appears that you have been giving more than passing attention to my formula
Pseudo-science should be beaten down whenever it rears its ugly head.
so not many SS would occur, and they may be hardly visible (LP).
The L-P effect [if it occurs] does not mean that the magnetic field is gone, so will have very little effect on the dynamo.
vukcevic (06:33:53) :
Since it appears that you have been giving more than passing attention to my formula
Pseudo-science should be beaten down whenever it rears its ugly head.