The Terminator Theory and Implications for growth of Cycle 25

[3gMike]

On 2/2/2023 at 11:59 PM, Scott McIntosh said:

Got questions? Fire away.....

Hi Scott, Thanks for joining this discussion and being open to questions.

I just picked up the latest WSO photospheric synoptic map updated on Feb 6th. I was interested to see that the magnetic fields in both hemispheres are becoming more closely packed, creating more opportunities for active regions. What I also noticed was that the peak field strength of quite a few of the fields seems to lie close to 15 deg latitude. I have marked up the map with lines at approx. 15 degrees to illustrate this point.

I also recognise that when 10.7cm flux climbed in late December that seemed to coincide with several ARs appearing at quite high latitudes, particularly in the northern hemisphere. The JSOC farside images also seem to be indicating increasing magnetic activity in the higher latitudes (up to about 40deg) of the northern hemisphere.

I would be interested to know if you think this has any significance - particularly in relation to field reversal.

 

[Scott McIntosh]

Hi Mike,

There is some recent work about the nature and spread of the bands.... this is all very very new and cool. I think its pretty normal to see spreads from 10-40 degrees at this time.

https://ui.adsabs.harvard.edu/abs/2021ApJ...922...46D/abstract

-Scott

[Philalethes]

As I was plotting some cycle data, I thought it'd be interesting to see a comparison between SC25 so far and the cycles closest to it on this diagram from Scott's work, containing the post-terminator prediction based on the previous delta:

What I'm thinking of as the closest here are specifically SC15 and SC20, since the former had roughly the same maximum as is predicted for this one and only a slightly longer preceding delta, while the latter ended up at a somewhat lower maximum but had roughly the same preceding delta. Here they are:

There's of course no guarantee that the cycle does end up fitting that relationship perfectly, as can be readily seen from the first plot there are plenty of outliers; but it's equally interesting to note that there are several cycles where the SSN seems to stall, and then rapidly rises again (you can in fact see exactly this in SC15), so there's ultimately still no predicting where SC25 will end up going when all is said and done.

Given the topic of this thread I suppose it's also fitting to use the terminator dates for the cycles instead (which were posted on page 1):

Note that this isn't normalized for terminator cycle length as Scott has done in some of the work discussed previously in the thread; since we don't know how long SC25 will be, we'd have to use the estimate for the length to do so, which I eyeball from the first plot to be roughly 10 years and 10 months. Then we'd get this instead:

Not that much different, but the shapes of the latter halves (post-peak) coincide quite well that way.

So based on this, assuming SC25 to be similar to either of those cycles, it's easy to see that the climb from the SSN minimum still has quite some way to maximum, unless it ends up being an outlier to this particular fit. Of course this isn't anything new, given that Scott's most recently published prediction is based on roughly the same, except that it's based on an idealized mean, here I just wanted to compare it to a couple of concrete examples instead.

I also thought it'd be interesting to plot all the cycles normalized and see if it were possible to spot some of milestones at the fifths of the cycles that Scott has mentioned; I was primarily interested in seeing how well the maxima of the cycles cluster around the first fifth (0.2 of the normalized cycle), which he considers to be clustered around the overall field reversal, but I also plotted the minima of the cycles (both represented by vertical bars, it's easy to see which are maxima and which are minima), and it looks like this:

That's quite interesting; there seems to be quite a bit of variability when it comes to the maximum, although it does noticeably cluster around that first fifth, particularly right before it. But more interesting is how the minima tend to cluster much more strongly around the fourth fifth (0.8), right after it. Quite an interesting symmetry, and this gives some interesting possibilities in allowing you to assume the terminator cycle length with more confidence once you reach what you can reasonably conclude is a SSN minimum, i.e. as the next cycle rises, but before the previous terminator has actually ended yet; but here too there are outliers, so even if you can have more confidence in such a prediction that way it doesn't mean you can be sure.

The coincidence of the fourth fifth and the minima was obviously spotted by Scott, as 3gMike mentioned it in the OP of the thread, but I find it curious that he'd claim this isn't very consistent, because it looks fairly consistent to me, with only a few outliers. Maybe @Scott McIntosh has a few thoughts to share about it if he ever stumbles back into the forum to have a look.

Edited May 5, 2023 by Philalethes
typo

[David Silver]

Excellent @Philalethes. No matter where the cycle starts, we def have a long way to go. 

[Philalethes]

20 minutes ago, David Silver said:

Excellent @Philalethes. No matter where the cycle starts, we def have a long way to go. 

That's definitely most probable in my book, at least. But I guess there are no certainties, although it would greatly surprise me if SC25 just suddenly dropped dead.

[Patrick P.A. Geryl]

2 uren geleden, Philalethes zei:

That's definitely most probable in my book, at least. But I guess there are no certainties, although it would greatly surprise me if SC25 just suddenly dropped dead.

Scott stated on Twitter that the high is before the end of 2023😱😳
and the same indicators that gave me the low between cycle 24 and 25 give now….

drum… drum…

May 2023🤔🤭🤩😳

so 

all my theories seem right

 

Edited May 5, 2023 by Patrick P.A. Geryl

[Philalethes]

He's predicting end of 2023 or early 2024. Also, he's still predicting a large increase in activity until then, which I'm not sure why you don't mention.

Meanwhile, you're predicting that the maximum SSN will be in May? That sounds extremely unlikely to me. Look e.g. at this plot:

This is how the SSN will evolve over time if we assume various flat means for the next 6 months. As you can see, for the SSN to peak in May (which is month 41 since SSN minimum in the plot), the mean has to be kept at 95 or below every single one of those months on average (not even accounting for the tapering of the last month); even SC24 with its huge drop down to 47.8 in February 2012 only barely managed to stay that low. Meanwhile the current average for this month is 117.8, well in line with how the cycle has developed so far. Even assuming the significantly lower average from last month of 96.4 would not achieve what you're claiming, and it'd have to stay there and not even reach the second peak that was observed for SC24 in that case.

It all sounds very unrealistic to me.

Anyway, this thread should be reserved for discussion of Scott's terminator framework, so if you want to discuss your own ideas or other things you should tag me in the appropriate thread for it.

Edited May 6, 2023 by Philalethes
corrections and extension of plot

[David Silver]

We may see A peak in late 23 / early 24, but that then will mean this is a 2-peak cycle, because again…it’s an 11 year cycle and it’s highly improbable that has changed. Repeating these opinions in various threads is probably not helpful.

[Philalethes]

10 minutes ago, David Silver said:

We may see A peak in late 23 / early 24, but that then will mean this is a 2-peak cycle, because again…it’s an 11 year cycle and it’s highly improbable that has changed. Repeating these opinions in various threads is probably not helpful.

I believe Scott is actually predicting a relatively synchronized peak around that time, i.e. that even if there is some separation there won't be much. He points to the synchronized recent closing of the polar coronal holes as evidence for this. It's definitely a bit early compared to what I'd expect, though; we'll have to see how it plays out.

[Patrick P.A. Geryl]

8 uren geleden, Philalethes zei:

 

Anyway, this thread should be reserved for discussion of Scott's terminator framework, so if you want to discuss your own ideas or other things you should tag me in the appropriate thread for it.

I wrote an article that was almost published about the faults in the Terminator theory. ORCID LINK 
Relating the Start to the Terminator of Solar Cycle 25 and a Significant X-Flare Event


https://www.authorea.com/users/539340/articles/599885-relating-the-start-to-the-terminator-of-solar-cycle-25-and-a-significant-x-flare-event
https://essopenarchive.org/doi/full/10.1002/essoar.10504257.1

So yes, it is all related.

By the way, you focus on the SSN, while you should focus on the 10.7 flux. Will fail.