Temporal Location of Solar Minimum Nadir for SC24/25 Transition

[Capricopia]

17 hours ago, theartist said:

By "optimistic", do you mean 'high' or 'low' sunspot activity'? Recall, Kitiashvili's 'low activity' forecast was considered by NASA as "favorable for next decade exploration" , but that may not be optimistic from the perspective of the aurora chasers.

Thanks for try to clarify some of my statements 🙂 It was euphemistic sarcasm, the ramp up in Sunspot numbers does not look feasible when compared to previous cycles, based on the emerging length and depth of this minimum. I am purely an amateur, but to my engineers eye, it just looks wrong for a natural process, especially when compared to SILSO standard Curves which has proved to be more in line over the last year ...

17 hours ago, theartist said:

Early 20th century cycles were NOT notably "longer"; early 19th century cycles (Dalton Minimum) were.

I actually referfenced the turn of the century and meant the period from 1870-1910 when the solar cycles were mostly >11.5 with 800-1000 spotless days compared to the later part of the 20th century when most cycles were <10.6 with under 300 days.  There is a good colourful illustration on SILSO spotless page, but their "Note there's no obvious correlation between the total number of spotless days and the subsequent solar cycle maximum (r2=0.35)."  seems to be at odds with this study https://iopscience.iop.org/article/10.1086/604667 that says

Quote

"..Based on our results, we have found evidence to show that the variability in the length of the solar cycle is statistically significant. In addition, we predict that the length of successive solar cycles will increase, on average, over the next 75 yr; and he strength of the sunspot cycle should eventually reach a minimum somewhere between Cycle 24 and Cycle 31, and we make no claims about any specific cycle....

All four historic minima since 1200 occurred during the rising portion of the 183 and 188 yr cycles when the length of the sunspot cycle was increasing. According to our analysis, the length of the sunspot cycle was growing during the Maunder Minimum when almost no sunspots were visible. Given this pattern of behavior, the next historic minimum should occur during the time when the length of the sunspot cycle is increasing.

The existence of long-term solar cycles with periods between 90 and 200 yr is not new to the literature but the nature of these cycles is still not fully understood. Our study of the length of the sunspot cycle shows that there is a dominant periodicity of 188 yr related to the basic Schwabe Cycle and weaker periodicities of ~40 and 87 yr. Our study also suggests that the length of the sunspot number cycle should increase gradually, on average, over the next ~75 yr, accompanied by a gradual decrease in the number of sunspots. "

 

[theartist]

On 12/30/2019 at 10:45 AM, 3gMike said:

assuming the tentative forecast for >950 for this minimum is correct, it would theoretically be possible to have more than 300 spotless days in 2020 followed by a very rapid decline in 2021.

Yes!  The period before SC15 had over 1000 spotless days, and yet its Peak monthly smoothed SSN was 175.7. The takeaway is that the 'spotless days metric' (particularly the way they compute it*) by itself does not have great predictive value, but it is an interesting data point when combined with other information.  

(*Spotless days in that graph are computed for the total time period between cycle maximums.)

On 12/28/2019 at 4:28 AM, cosnow said:

This seems important.

In my magnetogram posts (and on the Ap Index thread, etc.), I refer to something I call 'temporal equivalency' when attempting to compare how the current minimum epoch compares with, and temporally lines up with, previous cycles, in particular SC23, since the SC23 minimum displays similar attributes to that of the current cycle (in addition to us having more readily available magnetogram data for SC23).  An important distinction to make is that 'temporal equivalency' in terms of the comparative progression of magnetic activity (observed on the photosphere, i.e., the latitudes of advecting magnetic structures and their polarity) does not always equate to equivalent placement of Solar Minimum Nadir.  

On 12/28/2019 at 6:02 PM, Vancanneyt Sander said:

In fact the previous minimum was dreadfully long, but we now saw multiple SC25 regions and it’s also been a while already that we’ve seen a SC24 region.

In my latest post to the thread titled, "SC23 vs. SC24 Minimum Comparison, using MDI & HMI Synoptic Charts", I compare the magnetograms for the solar minimums of the last three solar cycles, and I highlight 'old-cycle' and 'new-cycle' regions according to their polarity (regardless of their latitude).  'Temporal equivalency' for this current cycle, in terms of the cycle's magnetic activity progression, puts December 2019 comparably equivalent to October 2008 (give or take a couple of Carrington Rotations, at most).

On 12/28/2019 at 3:57 AM, The Norwegian said:

The question is whether they will be strong enough so that we see them, since we are at a deep minimum now.

Yes, that is one of the issues that can cause the SMN to temporally deviate from an equivalency that is strictly based on the progression/location of advecting photospheric magnetic structures, since not all mag-structures produce sunspots, and if they do, they may not last long if they are magnetically weak. 

Edited January 1, 2020 by theartist

[NotEnuffEvidence]

@theartist every time I come here to read this forum you're stance seems in favor of a maunder minimum. How do you actually know? You seem to take solar minimum to the extremes it isn't. The sun will and always have stumped many theories. I do not subscribe to your assumptions. I wish you would stop predicting the sun as if your assumptions are gospel. I listen to astrophysicists who are very much more objectionable. All this isn't science. This is your assumptions only. 

Just watch the sun forming small active regions. Some may or may not be sunspots. To the human perspective, the sun is slow to progress. We can't live 10 billion years to be certain any of this makes sense. I don't rely on butterfly graphs from past Solar Cycles because the next one has always been different from the last. Trends are neither consistent. 

Physics change at a certain temperature. Then nothing makes sense. This applies the sun. 

Edited January 1, 2020 by NotEnuffEvidence

[The Norwegian]

13 hours ago, theartist said:

On 12/28/2019 at 10:57 AM, The Norwegian said:

The question is whether they will be strong enough so that we see them, since we are at a deep minimum now.

Yes, that is one of the issues that can cause the SMN to temporally deviate from an equivalency that is strictly based on the progression/location of advecting photospheric magnetic structures, since not all mag-structures produce sunspots, and if they do, they may not last long if they are magnetically weak. 

The most interesting thing about an solar minimum is that every change on the solar disc becomes visible. Today we can see the beginning of a tiny spot far south on the solar disc. At the same time Mercury is in line with Saturn. If Saturn also affects the magnetic field of the sun, in respect to sun spots, well then I learned something new today  

[theartist]

16 hours ago, NotEnuffEvidence said:

@theartist every time I come here to read this forum you're stance seems in favor of a maunder minimum.

Do you have any evidence to support that conclusion, or did you spend less than five minutes on the forum before deciding that? 

[theartist]

On 12/30/2019 at 9:31 PM, Capricopia said:

the ramp up in Sunspot numbers does not look feasible when compared to previous cycles, based on the emerging length and depth of this minimum. I am purely an amateur, but to my engineers eye, it just looks wrong for a natural process,

Yes!  I like the way you put that. It would be indeed strange if the sun activity abnormally took off like a jack-rabbit.🙂 Here at the spaceweatherlive.com forum we are investigating planetary clocking's effects on the sun's expression of magnetic activity, and I think a critical thinker like you would be an asset to the team.

On 12/30/2019 at 9:31 PM, Capricopia said:

"Note there's no obvious correlation between the total number of spotless days and the subsequent solar cycle maximum (r2=0.35)."  seems to be at odds with this study

Thanks for the paper reference.  I like the idea of applying power spectral analysis to the historical sunspot records, and their 'periodicity findings' may be quite useful/affirmative in our 'planetary clocking'  analysis.  However, after looking more closely at that paper, I don't think their conclusion regarding solar cycle length's "increase, on average, over the next 75 yrs" is all too definitive.  Also, to understand that a longer cycle will be associated with magnetic weakness is just an intuitive conclusion we are already making here on the forum, even in this thread, that doesn't require much math to do so.  

I've already pointed out in this thread the possibility that in comparing two solar cycles, there may be some disconnect between the 'temporal equivalency' of the magnetic cycle progression (observed in the magnetograms) and the actual location of Solar Minimum Nadir (after the average smoothed-monthly is computed), if the cycles vary significantly in the strength of their solar activity.  Nonetheless, although more investigation could be done (it would be nice to have more historical magnetogram data), I do think assigning 'temporal equivalency' based on the magnetic cycle progression (observed in the magnetograms) will get us in the ballpark of deducing where the SMN is going to lie.  And certainly, magnetogram information is much more conclusive than the 'spotless days' metric when assessing the potential strength of the next cycle.  

On 12/30/2019 at 12:44 PM, 3gMike said:

You queried who is represented by ISES. In fact it represents SWPC and SIDC, along with a lot of other national bodies.  Their website...

Thanks, before you posted, I found and briefly looked at their website, on which they hadn't updated their news in a few years, so who knows whether they are still involved (or need to be anyway).

[theartist]

8 hours ago, theartist said:

the 'temporal equivalency' of the magnetic cycle progression (observed in the magnetograms) 

To be clear, what I'm referring to is the trend to first see new cycle magnetic activity above +32 deg latitude, and displaying a progression poleward early in the cycle, before agglomerating primarily in the lower latitudes, as shown in the following Butterfly Diagram by Maunder (graph source) :

[theartist]

noob, there is the 'photospheric network' and the 'chromospheric network'.  The manifestation of their interrelationship depends on the intensity of the agglomerated magnetic fields.  What I highlighted in that imagery is a string of 'bright points', which are tiny 'flare regions' up in the chromosphere and corona.  Faculae are down on the photosphere.

Maybe you have read a definition elsewhere that faculae are "tiny torches"?  The 'tiny torches of facula' are actually located down around the granules bubbling on the surface of the photosphere.  An agglomeration of this activity appear as a larger illuminated area, on the photosphere, in a lighter color in either white light imagery or in the HMI Intensitygram.  

7 hours ago, noobsauce said:

Faculae are weak magnetic structures (google) so this could be a valid hypothesis?

Rather, faculae are an agglomeration of magnetic activity stronger than the surrounding, relatively quiescent, photosphere.  

7 hours ago, noobsauce said:

Maybe strings of Equitorial faculae are a measure of solar cycle ends (ie: actual death of SC24) before the observable magnetic field change at the next cycle(SC25) due to magnetic weakness at solar cycle death before reversed magnetic strength of next  cycle begin? 

The equatorial "bright points" were likely indicative of underlying magnetic field agglomeration along the boundary of very large supergranules.   The quiescent state of the global magnetic activity allowed these singular lines of 'bright points' to manifest; conversely, they would get lost in a state of more chaotic magnetic activity, like during solar maximum, or even in a less-weak minimum epoch.  For example, the minimum nadir at the end of SC22 was 'stronger' than during this current minimum (thus, a relatively long-standing ring of "bright points" possibly never formed during the SC22 minimum epoch).  One can observe the 'stronger' SC22 minimum epoch in comparing the magnetograms of the past three solar cycles:

.

[Capricopia]

SIlso have just updated their data on spotless days and forecast for SC2425 transition.  

Quote

Assuming the current number of spotless days continues to track the evolution of the SCo cycles, a solar cycle minimum in May 2020 (+/- 10 months) can be expected.  The current fast rise in spotless days nearly coincides with that of the previous solar cycle transit

http://www.sidc.be/silso/spotless

[Aeon]

I have a question:

Solar cycle 23 was particularly long about 12.3 years.

It has always been said that weak cycles last longer.

Since solar cycle 24 has been further weaker, should it not logically be longer than solar cycle 23?

Thanks