Growth of Cycle 25

[3gMike]

39 minutes ago, hamateur 1953 said:

Thanks @3gMike  That’s definitely good news as far as the future evolution of this cycle goes.  Appreciate you posting this!   Mike. 

For comparison I have also plotted Cycle 24 with markers for the two peaks in that cycle. This plot makes it clear that we cannot directly relate position of peaks to the state of polar fields.

[hamateur 1953]

9 minutes ago, 3gMike said:

For comparison I have also plotted Cycle 24 with markers for the two peaks in that cycle. This plot makes it clear that we cannot directly relate position of peaks to the state of polar fields.

Even more interesting and food for thought.  

[Philalethes]

5 hours ago, hamateur 1953 said:

Awhile back perhaps in another thread, I don’t recall right now, but I think it was @Philalethes who was discussing where we were with the most recent polar field data.  It might have been  @3gMike too.   Since we are entering a lull in activity for the present time, I was curious if anyone has been looking into these figures recently.  Tnx. Mike. 

I've posted some plots of the HMI polar fields data previously; I was going to wait until all of February was in, but now that only the infamous Feb 29 is missing I've updated some of them.

First off is the one looking at the averages for the different caps (a "cap" being all the way from a certain latitude to the pole):

I've noted before that there's some behavior here that doesn't appear as clearly in the WSO data, especially how the different caps seem to converge at 0 one after the other, before all moving together towards the more stable dipole field we see during minima. It bears repeating that this is just one data point, but what it implies in this case at least is that the field essentially pauses the transition to the opposite polarity at the lower latitudes (50°-70°) and hovers around 0 until the very highest latitudes (70°+) flip, at which point the opposite polarity increases in strength at all the latitudes.

As I've mentioned before, it seems like in this case the overall peak of SC24 coincided with the time the 70°+ cap crossed over and all the latitudes moved with it; this period of greatest convergence corresponds fairly well to the time of maximum, with the least difference between the three having been in July (maximum having been in April). This could naturally be a coincidence, but it's an interesting observation, I'll definitely be looking to see if something similar might happen for SC25. I know Scott has always talked before about how maximum tends to be associated with the time spent "teetering" around 0, and if I recall correctly from the thread he made a while ago there did seem to be a leaning towards the end of that teetering period for the maximum, which would be what we're looking at here.

I would also note that the individual months of the highest activity were actually a bit before the maximum in SC24, and that the April maximum was the result of this combined with some smaller peaks on the way down a few months after it. Trying to find relationships between those individual peaks and the overall field averages at any given point in time is probably not going to yield any good results though, at least I'd assume you'd need more detailed analyses for that, and at the very least to look at the rate of change.

Looking at the current situation for SC25, it's interesting to note that the 50°+ cap has flipped more to the other side than we saw for the SC24 reversal, but it does seem to have flattened out for now, as one would expect if the SC24 reversal is at all typical (which there's of course no guarantee for). If that's the case we might expect the 60°+ field to converge to the 50°+ one at some point and stay there until the 70°+ field crosses over and they all move. And if that does in fact have some association with peak activity it would mean that we'd be unlikely to be at maximum yet, but to reiterate that's definitely not a given at all. Will be very interesting to see in the upcoming months.

Here's the same plot, but using the individual bands (i.e. restricted to just the separate ranges of latitude than the overlapping caps, with only the 70°+ being the same, since it essentially represents both a cap and a band):

We see more or less the same here, but here we can really see for the SC24 reversal how the field does indeed seem to "pause" near 0 at the lower latitudes until the higher latitudes flip and everything moves. We also see more clearly towards the SC25 end how the lower latitude fields started flipping quite a while back (when certain threads were starting to get made on the topic), and how even the 60°-70° field flipped quite some time ago, but that we might still see them converge and wait for the 70°+ field to flip like for SC24.

Last one here is of just the 60°+ and 70°+ caps, but with the two field components plotted for each, and only for the past 3 years:

We see that while the 60°+ flip has been fairly symmetrical, aside from some imbalance towards the end of 2022, the 70°+ flip does not appear to be, at least not as it looks right now. The northern field there has even reached 0 already, with just the southern field having pulled back and being responsible for the still unflipped average.

All in all these are really just observations about the state of the overall field over time, any specific relations of this to sunspot activity remain speculative, although we do of course know that the two are connected in at least some broad sense, whether directly or by proxy. Personally I think some of what I've mentioned above might be interesting to at least look out for though, and given how it would track well with various other predictions of SC25 maximum I'd still guess that we're not there yet, but that we'll rather see it in the form of some larger bursts of activity over the coming months.

[hamateur 1953]

7 hours ago, Philalethes said:

I've posted some plots of the HMI polar fields data previously; I was going to wait until all of February was in, but now that only the infamous Feb 29 is missing I've updated some of them.

First off is the one looking at the averages for the different caps (a "cap" being all the way from a certain latitude to the pole):

I've noted before that there's some behavior here that doesn't appear as clearly in the WSO data, especially how the different caps seem to converge at 0 one after the other, before all moving together towards the more stable dipole field we see during minima. It bears repeating that this is just one data point, but what it implies in this case at least is that the field essentially pauses the transition to the opposite polarity at the lower latitudes (50°-70°) and hovers around 0 until the very highest latitudes (70°+) flip, at which point the opposite polarity increases in strength at all the latitudes.

As I've mentioned before, it seems like in this case the overall peak of SC24 coincided with the time the 70°+ cap crossed over and all the latitudes moved with it; this period of greatest convergence corresponds fairly well to the time of maximum, with the least difference between the three having been in July (maximum having been in April). This could naturally be a coincidence, but it's an interesting observation, I'll definitely be looking to see if something similar might happen for SC25. I know Scott has always talked before about how maximum tends to be associated with the time spent "teetering" around 0, and if I recall correctly from the thread he made a while ago there did seem to be a leaning towards the end of that teetering period for the maximum, which would be what we're looking at here.

I would also note that the individual months of the highest activity were actually a bit before the maximum in SC24, and that the April maximum was the result of this combined with some smaller peaks on the way down a few months after it. Trying to find relationships between those individual peaks and the overall field averages at any given point in time is probably not going to yield any good results though, at least I'd assume you'd need more detailed analyses for that, and at the very least to look at the rate of change.

Looking at the current situation for SC25, it's interesting to note that the 50°+ cap has flipped more to the other side than we saw for the SC24 reversal, but it does seem to have flattened out for now, as one would expect if the SC24 reversal is at all typical (which there's of course no guarantee for). If that's the case we might expect the 60°+ field to converge to the 50°+ one at some point and stay there until the 70°+ field crosses over and they all move. And if that does in fact have some association with peak activity it would mean that we'd be unlikely to be at maximum yet, but to reiterate that's definitely not a given at all. Will be very interesting to see in the upcoming months.

Here's the same plot, but using the individual bands (i.e. restricted to just the separate ranges of latitude than the overlapping caps, with only the 70°+ being the same, since it essentially represents both a cap and a band):

We see more or less the same here, but here we can really see for the SC24 reversal how the field does indeed seem to "pause" near 0 at the lower latitudes until the higher latitudes flip and everything moves. We also see more clearly towards the SC25 end how the lower latitude fields started flipping quite a while back (when certain threads were starting to get made on the topic), and how even the 60°-70° field flipped quite some time ago, but that we might still see them converge and wait for the 70°+ field to flip like for SC24.

Last one here is of just the 60°+ and 70°+ caps, but with the two field components plotted for each, and only for the past 3 years:

We see that while the 60°+ flip has been fairly symmetrical, aside from some imbalance towards the end of 2022, the 70°+ flip does not appear to be, at least not as it looks right now. The northern field there has even reached 0 already, with just the southern field having pulled back and being responsible for the still unflipped average.

All in all these are really just observations about the state of the overall field over time, any specific relations of this to sunspot activity remain speculative, although we do of course know that the two are connected in at least some broad sense, whether directly or by proxy. Personally I think some of what I've mentioned above might be interesting to at least look out for though, and given how it would track well with various other predictions of SC25 maximum I'd still guess that we're not there yet, but that we'll rather see it in the form of some larger bursts of activity over the coming months.

More good news ahead.   Thanks for the input on our sun’s coming increased output @Philalethes.  Always nice to see optimism in these pages, especially when the ARs are disappointing us in other areas like geomagnetism.  

Edited March 4 by hamateur 1953

[Patrick P.A. Geryl]

20 minuten geleden, hamateur 1953 zei:

More good news ahead.   Thanks for the input on our sun’s coming increased output @Philalethes.  Always nice to see optimism in these pages, especially when the ARs are disappointing us in other areas of geomagnetism.  

Mmmmm… The minions are working overtime… 10.7 flux down…🤔🤣

[Philalethes]

2 hours ago, Patrick P.A. Geryl said:

10.7 flux down…

81-day average clearly moving up, though, as we've seen a series of peaks and troughs that have been rising on average:

The 365-day average is slightly down from the peak, but if previous cycles are any indication there's still a good chance that we're not at the peak of the entire cycle at all:

Some cycles do have the earlier peak as the largest one, like SC22, but even then you typically still see a noticeable second peak. There are also single-peaked cycles like the infamous SC19, but in those cases you'd expect the time of the peak to come significantly later for weaker cycles like SC25.

[hamateur 1953]

The next two years should prove to be interesting.  Especially as continuous evaluation pulls us away from last June and leaves it remaining only a minor peak in sunspot numbers and solar flux in the evolution of Cycle 25.  The current drop in numbers and flux I expected.  The next few highs should be really interesting.  Especially as I am hoping to have a few opportunities to test a theory on Es and flaring ionisation over our summer months this year. ( I claim no originality as far as it goes, it has been likely considered before)    I remember @Philalethes that you seemed a bit surprised at how far down the cycle they had pushed the A index maximums.  If I am correct, you weren’t the only one!   I would imagine it being around mid 2025 or 2026.  If I am not mistaken they had it around 2027 or something like that.  Correct me if I’m wrong, naturally. Thanks again for the input @Philalethes appreciate it. Mike. 

Edited March 4 by hamateur 1953

[Philalethes]

30 minutes ago, hamateur 1953 said:

Especially as I am hoping to have a few opportunities to test a theory on Es and flaring ionisation over our summer months this year.   I remember @Philalethes that you seemed a bit surprised at how far down the cycle they had pushed the A index maximums.

Yeah, I also seem to recall that the predicted peak in the imagery we were discussing was set to be around 2026-2027 or so, definitely later than I had expected. Of course we'll have to wait and see, maybe in the meanwhile I'll dig up some of the Ap-index data I've been looking at previously and see how the peaks typically compare to the SSN maxima of previous cycles, would be interesting to see. Presumably the estimate we were looking at was based on such comparisons.

Not sure if that necessarily correlates to the F10.7 though, I'd think that peak would come a bit earlier in general.

[hamateur 1953]

2 minutes ago, Philalethes said:

Yeah, I also seem to recall that the predicted peak in the imagery we were discussing was set to be around 2026-2027 or so, definitely later than I had expected. Of course we'll have to wait and see, maybe in the meanwhile I'll dig up some of the Ap-index data I've been looking at previously and see how the peaks typically compare to the SSN maxima of previous cycles, would be interesting to see. Presumably the estimate we were looking at was based on such comparisons.

Not sure if that necessarily correlates to the F10.7 though, I'd think that peak would come a bit earlier in general.

Agreed, the 10.7 could lead it by a year easily. And probably should, although I have never correlated the two indexes, although they are somewhat related, the geomagnetic stuff typically peaks much later in most cycles that I am aware of anyway. 

[Mick]

I'm a newbe on solar data on which dates do we see that the solar maximum has been reached? Can we see that?

[tniickck]

19 minutes ago, Mick said:

I'm a newbe on solar data on which dates do we see that the solar maximum has been reached? Can we see that?

It hasn't happened yet 

[Newbie]

27 minutes ago, Mick said:

I'm a newbe on solar data on which dates do we see that the solar maximum has been reached? Can we see that?

The timing of solar maximum is inherently challenging to predict accurately, and it is not definitively known until the event unfolds. This uncertainty is due to the dynamic and variable nature of the Sun's behaviour.

Several indicators, such as sunspot number, solar magnetic field strength, and other solar activity indicators are used to estimate when solar maximum might occur. However, these indicators may show fluctuations and unexpected variations, making it difficult to precisely pinpoint the exact moment of solar maximum.

Previous solar cycles are painstakingly analysed, but it is my belief that no two solar cycles are exactly the same.

The manifestation of this uncertainty is observed in the gradual rise and fall of solar activity during a solar cycle. The actual confirmation occurs retrospectively as solar activity begins to decline after reaching its peak.

Advancements in observational technologies and predictive models may contribute to reducing uncertainties, but the complex and dynamic nature of the Sun's behaviour means that predicting the exact timing of solar maximum remains a challenging task.

At this point in time solar maximum hasn’t been determined.

N.

Edited March 6 by Newbie

[hamateur 1953]

3 hours ago, Kayla Bisson said:

Maybe this cycle will be more of a grow-er than a show-er, many pages (Jan Alvestads included) put the potential Solarmax possibly into 2025, what kind of numbers/signs would we need to see for that to be our reality?

That’s a very good question, @Kayla Bisson As far as numbers, I won’t even hazard a guess.   However we will be given a very good indicator by the declining latitudes of the emerging active regions which will be much nearer the solar equator at Solar Maximum.  As you may have read already, the southern pole has apparently done its polarity reversal and presently we are expecting the northern pole to follow suit within the next year or so.  When that finally happens, as I understand it, we are then at  Solar Maximum.  Hopefully this helps, not confuses.  Mike.   Btw the last latitude check was 18.5 degrees on nine regions, still quite high imo. We have had a few low latitude checks, but these have not persisted, hence my belief we are still a good 3-9 months from Solar Max. 

Edited March 6 by hamateur 1953
Latitude

[Jay-B]

2 hours ago, hamateur 1953 said:

Btw the last latitude check was 18.5 degrees on nine regions, still quite high imo. We have had a few low latitude checks, but these have not persisted, hence my belief we are still a good 3-9 months from Solar Max.

How often do you do these checks? Do you do them on a certain day each month to ensure consistency?

[hamateur 1953]

1 hour ago, Jay-B said:

How often do you do these checks? Do you do them on a certain day each month to ensure consistency?

I have been doing them monthly at or near the first of each month if I have at least eight active regions to include in the averages.  Because they are on our side for a week at a minimum, the exact date is less important.  I january we dipped below 12 degrees in one hemisphere. I was separating the hemispheres for awhile In case I wanted to check hemispheric development later.  I didn’t this last time because the latitudes were looking very close this time.  Btw it isn’t uncommon to get a wild one like the 37 degree AR.  I include these in average too.  

[Archmonoth]

9 hours ago, Kayla Bisson said:

Maybe this cycle will be more of a grow-er than a show-er, many pages (Jan Alvestads included) put the potential Solarmax possibly into 2025, what kind of numbers/signs would we need to see for that to be our reality?

Maybe some more x class flares? We already have had a few, so perhaps we will go to plaid once more. I don't think the solar max will go into 2025. 

 

My 2 cents. 

 

@Ingolf I sent the link to the other thread via a message on the site. If you didn't receive it, here is the forum link for the thread: 

 

[hamateur 1953]

34 minutes ago, Archmonoth said:

Maybe some more x class flares? We already have had a few, so perhaps we will go to plaid once more. I don't think the solar max will go into 2025. 

 

My 2 cents. 

 

@Ingolf I sent the link to the other thread via a message on the site. If you didn't receive it, here is the forum link for the thread: 

 

Hey @Archmonoth I’m all in, especially if it means higher sunspot numbers and of course higher 10.7!  Something is driving that dynamo, on this we can all agree.  

[Lawn Boy]

On Solen, Jan’s chart of the solar polar fields versus solar cycles, he has the reversal average after both the north and south reversals. How is that possible? And what does it mean.

I tried to add the graft, but it wouldn’t let me. 
https://solen.info/solar/polarfields/polar.html

[hamateur 1953]

I will tag @3gMike  this is a fairly complex issue ( to me anyway). Hopefully he is around, otherwise I think @Philalethes may be able to handle it for ya.  @Newbieis around too. Hopefully she sees this. 

Edited March 7 by hamateur 1953

[Philalethes]

2 hours ago, Lawn Boy said:

On Solen, Jan’s chart of the solar polar fields versus solar cycles, he has the reversal average after both the north and south reversals. How is that possible? And what does it mean.

I tried to add the graft, but it wouldn’t let me. 
https://solen.info/solar/polarfields/polar.html

You could get something like that if the northern field first crosses, but then pulls back again while the southern crosses, so that the two have never crossed each other yet at that point, just crossed zero (average crossing zero would be when the two cross each other).

However, I do find it a bit strange from looking at the WSO data here, because while it does indeed show the northern field pulling back in that manner, it seems like there that the average still flipped slightly before the southern one (looking at the filtered values, the three columns on the right).

Addendum:

Here's a plot of the 50°+ field as captured by HMI (not the data Jan is using, this is just for illustration purposes) where you can see what I mean, with first the southern field flipping, then the two moving in tandem so that the southern field pulls back and "re-flips" while the northern field flips, and then the two finally cross each other so that the average flips:

Edited March 7 by Philalethes
addendum (illustration)

[Newbie]

24 minutes ago, hamateur 1953 said:

I will tag @3gMike  this is a fairly complex issue ( to me anyway). Hopefully he is around, otherwise I think @Philalethes may be able to handle it for ya.  @Newbieis around too. Hopefully she sees this. 

@Lawn Boy

I take it you mean how can one polar field flip without the other field flipping at the same time?

The solar polar magnetic fields exist independently of each other. The Sun's magnetic field is complex and dynamic, and it undergoes a complete reversal of its polarity approximately every 11 years during the solar cycle.

Each solar hemisphere (northern and southern) has its own polar magnetic field. When the Sun is at solar minimum, the polar fields reach their maximum strength, and their orientation is relatively stable. As the solar cycle progresses, sunspots and active regions emerge, causing the magnetic fields to become more dynamic.

During solar maximum, sunspots and magnetic activity reach their peak, and the overall solar magnetic field becomes more turbulent. This turbulence results in the gradual weakening and reversal of the polar magnetic fields.

The reversal of the solar polar fields is a key feature of the solar cycle, and it occurs somewhat independently in each hemisphere. The specific dynamics and timing of these reversals contribute to the overall complexity of the Sun's magnetic behaviour.

The term "flipping" is often used to describe the reversal of the Sun's magnetic poles during the solar cycle, but it's essential to clarify that this process doesn't involve a literal flipping or inversion of the entire solar magnetic field. Instead, it refers to the reversal of the magnetic polarity in specific regions of the Sun, ie specific latitudinal bands or zones where these magnetic changes occur define the regions experiencing magnetic field reversal

N.

[Lawn Boy]

I would say that Newbie is a misnomer. Thank you for your explanation. I will have to read it a few more times to soak it all in. You too Phil. But in answer to your first response, it just seems to me that if one flips and then another flips later on then the average is in between. Which it is in the earlier crossings in that graph.

[Patrick P.A. Geryl]

From Solen

(last text update: 2024.03.03)

The development of the solar polar field strength throughout a solar sunspot cycle can be used to predict the magnitude of the next cycle and the peak of the current cycle. Polar field reversals typically occur within a year of sunspot maximum. It is not uncommon for the northern and southern polar fields to have significant differences in field strength and develop asynchronously over time. The Wilcox Solar Observatory has been collecting solar polar field data since 1975. Non-filtered data can be viewed in this plot. Below you will find a plot where only the filtered (by a 20 nHz lowpass filter) field strength data is displayed. Vertical lines representing field reversals and sunspot cycle min/max have been added to increase the potential usefulness of the plot.

For solar cycle 24 the northern polar field changed polarity first in June 2012, then weakened and was near neutral in April 2014. The southern polar field reversed in July 2013. During the previous similar polarity reversal in 1989-1991 the northern polar field reversed 14 months prior to the southern polar field reversal. The northern polar field peaked in September 2019 while the southern polar field reached its peak in November 2015.

The strength of the polar fields at their peak during cycle 24 indicated that solar cycle 25 could reach a magnitude somewhere between those of cycles 23 and 24. The northern polar field reversed polarity the first time in April 2023 while the southern polar field reversed in August 2023 and the total field in November 2023.

❤️❤️❤️

The SC25 solar max may already be in the past as the 365-day smoothed solar flux peaked on June 27, 2023. Should solar activity in March and April 2024 be relatively high that peak could move to November 2023.

That says it all

💕💕💕

[Newbie]

1 hour ago, Patrick P.A. Geryl said:

From Solen

(last text update: 2024.03.03)

The development of the solar polar field strength throughout a solar sunspot cycle can be used to predict the magnitude of the next cycle and the peak of the current cycle. Polar field reversals typically occur within a year of sunspot maximum. It is not uncommon for the northern and southern polar fields to have significant differences in field strength and develop asynchronously over time. The Wilcox Solar Observatory has been collecting solar polar field data since 1975. Non-filtered data can be viewed in this plot. Below you will find a plot where only the filtered (by a 20 nHz lowpass filter) field strength data is displayed. Vertical lines representing field reversals and sunspot cycle min/max have been added to increase the potential usefulness of the plot.

For solar cycle 24 the northern polar field changed polarity first in June 2012, then weakened and was near neutral in April 2014. The southern polar field reversed in July 2013. During the previous similar polarity reversal in 1989-1991 the northern polar field reversed 14 months prior to the southern polar field reversal. The northern polar field peaked in September 2019 while the southern polar field reached its peak in November 2015.

The strength of the polar fields at their peak during cycle 24 indicated that solar cycle 25 could reach a magnitude somewhere between those of cycles 23 and 24. The northern polar field reversed polarity the first time in April 2023 while the southern polar field reversed in August 2023 and the total field in November 2023.

❤️❤️❤️

The SC25 solar max may already be in the past as the 365-day smoothed solar flux peaked on June 27, 2023. Should solar activity in March and April 2024 be relatively high that peak could move to November 2023.

That says it all

💕💕💕

Dear Paddy 😊

The statement about already passing the solar maximum is based on the observation that the 365-day smoothed solar flux peaked on June 27, 2023, and the suggestion that if solar activity in March and April 2024 is relatively high, the peak could move to November 2023. 
Now should solar activity increase in June and July of this year (2024) where does that leave the new peak?

Are you saying both polar fields have flipped permanently? Really?

Interpreting solar cycle maxima involves various indicators, and smoothed solar flux is one of them.
While the smoothed solar flux is a valuable metric, considering sunspot observations is equally crucial in solar cycle assessments. Sunspots directly reflect the Sun's magnetic activity and their characteristics contribute significantly to determining the solar cycle’s progression. It is therefore best practice to consider multiple factors when determining the solar cycle's maximum. Solar activity can be complex and dynamic, and conclusions about solar maxima are typically made retrospectively with a comprehensive analysis of various solar parameters.

If the statement is based on a single metric, it's essential to approach such predictions with caution and await a more thorough analysis of solar activity trends over time. Scientists often use a combination of indicators, including sunspot numbers, solar irradiance, and magnetic field data, to provide a comprehensive assessment of solar cycle characteristics. You already know all this Paddy at least you are talking in maybes now and not definitives.

N.

 

[Philalethes]

7 hours ago, Lawn Boy said:

But in answer to your first response, it just seems to me that if one flips and then another flips later on then the average is in between. Which it is in the earlier crossings in that graph.

I'm not entirely sure what you mean by that. If the average were to lie in between the two, then you could have the average flip without either the northern or the southern flip. I think the key thing to understand is that the total strength of the field is measured by the difference between the two fields rather than the sum, due to its nature as a magnetic field. In other words, if you have e.g. 1 G in the northern and -1 G in the southern, the total field is 1 G - (-1 G) = 1 G + 1 G = 2 G, not 1 G - 1 G = 0; so the average would then be 2 G / 2 = 1 G, not 0 G / 2 = 0 G.

That's why you see when the northern field is at roughly 1.5 G and the southern field is at roughly -1.5 G that the average is roughly 1.5 G, not 0 G. The calculation would be 1.5 G - (-1.5G) / 2 = 1.5 G + 1.5 G / 2 = 3 G / 2 = 1.5 G. This is why you can see both of the fields moving together below the average line, because as long as the fields don't cross each other, the average remains above 0; it's only the moment the two fields cross each other that the average flips.