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SOLAR CYCLE 25 Prediction/Forecast by SpaceWeatherLive Forum


theartist

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EDIT on 10/22/19: Based on the current magnitudes of the SORCE Solar Spectral Irradiance centered around ~677nm, as indicated by the SORCE SIM database, we are slashing our forum's forecast for the SC25 Sunspot Peak Range by 15 points.  The Sunspot Peak Range has now been changed to 75-110 to reflect these findings.  Further assessment is expected in the future.

EDIT on 10/20/19:  The F10.7cm is the process of double-dipping. The Sunspot Peak Range will be slashed by 10 points immediately; further assessment is expected in the future. 

EDIT on 8/28/19: The "Bremen Metric" is not holding up, with regard to its initial interpretation/determination of Solar Minimum.  The Solar Minimum window needs to be updated.  A revised estimate for the occurrence of Solar Minimum is now "before mid-2020", but this is cursory, and requires further analysis to determine whether it warrants further modification/improvement.

This first 'headline' post in this thread will contain a summary of the prediction arrived at by concensus of this community forum.  Check back from time to time as it is updated.  Posts that follow this first 'headline' post will give supporting evidence as to how the consensus was arrived at.  

  • Solar Minimum (i.e., the Nadir of Cycle 24 which is the "Start" of Cycle 25):   before March 2019, and likely January or February 2019. 
    • (Note, this is based on the "Bremen Metric" discussed in this thread,  Solar Cycle 25 has already "started", in combination with up-to-date review of the ISN Daily Total, Monthly Mean Total, and 13-month Smoothed Monthly Total.)
  • Solar Maximum (Peak):   within period  Nov. 2021-to-Nov. 2024.
    • (Note, that is 5.2 yrs +/- 1.5 yrs from Solar Minimum.) 
  • Sunspot Peak Range:  100-to-135   90-125 75-110.
    • (Note, with a 20% chance > 135 125 110, and 5% chance <100 90 75. These numbers will likely be modified with further review of the evidence. Current consensus is biased toward SC25 being as strong or stronger than as weaker than SC24.)
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On 7/14/2019 at 2:13 AM, theartist said:

Solar Maximum (Peak):   within period  Nov. 2021-to-Nov. 2024.

  • (Note, that is 5.2 yrs +/- 1.5 yrs from Solar Minimum.) 

The average Time of Rise for all of the past 24 solar cycles is 4.4 years, per List_of_solar_cycles.  However, we've chosen to be selective of the cycles to include in the computation of the average.  Below is a plot of the 'weak' solar cycles.  These are the seven (7) cycles that met The Panel's Peak Range prediction (as discussed in this thread:  Solar Cycle 25 Predictions/Forecasts by 'The Panel' & NASA.)

1466286149_ScreenShot2019-07-15at2_35_38AM.thumb.png.1e40ae13cb836f939c2dc234e7b9dc61.png

We can toss out SC5, since it did not meet The Panel's Rise Time to Solar Maximum prediction.  The average Time of Rise for the remaining six (6) cycles is 5.2 yrs.  A three-year window for Peak was selected by The Panel in their prediction, and thus, our forecast is for the Solar Maximum (Peak) to occur within a three-year window centered around the 5.2 yr projected Time of Rise.

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  • Vancanneyt Sander changed the title to SOLAR CYCLE 25 Prediction/Forecast by SpaceWeatherLive forum
On 7/14/2019 at 2:13 AM, theartist said:

Current consensus is biased toward SC25 being as strong or stronger than SC24.

Marcel, over on the Solar Cycle 25 has already "started". thread, you state,

On 6/29/2019 at 5:02 AM, Marcel de Bont said:

a short minimum...would increase the chances of SC25 being stronger than SC24

Do you care to elaborate further here on this point?

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There is an accepted methodology called the solar cycle 'precursor method' scientists use when predicting solar cycles. Generally speaking, they are able to predict more accurately the size of the coming solar cycle once the solar minimum has passed, usually by 1-2 years. This method basically means that if the solar minimum phase was shorter (300-400 spotless days, or 1-2 years), then the following solar cycle will be more active than average. Likewise, if the solar minimum was longer (600-900 spotless days, 2-3 years) then the following solar cycle will be less active than average. This data and more is on the Belgian solar activity website spotless days page http://www.sidc.be/silso/spotless. The only drawback of this method is that it can only predict the solar cycle several years after the solar minimum.

In terms of making earlier predictions (before the solar cycle minimum), the most successful theory so far has been developed by Stanford University solar physics professor Leif Svalgaard. This is the Solar Polar Fields method. At Stanford they have been monitoring the strength of the solar polar fields since 1976 and found that this can predict the coming solar cycle more accurately than other methods ahead of time. Basically, the stronger the solar polar fields are at solar minimum, the stronger the coming solar cycle will be, and vice versa. In this current solar minimum, the polar fields are a little stronger than at the previous solar minimum, but still weaker than other solar cycles. This has led Professor Svalgaard to predict that Solar Cycle 25 will be marginally stronger than the Solar Cycle 24 just passed. The solar polar fields method is also the one endorsed & used by NOAA for early predictions. 

The values of the solar polar fields can be monitored at the Stanford Wilcox Solar Observatory webpage http://wso.stanford.edu/Polar.html

Below is a graph showing Svalgaard's prediction  - and the related article is here https://tallbloke.wordpress.com/2018/06/09/leif-svalgaard-reveals-his-solar-cycle-25-prediction-at-last/

image.png.3146fab2cfe0a553db7bda99372d8853.png

 

And here is a statement from Leif Svalgaard http://lasp.colorado.edu/media/projects/SORCE/meetings/2018/Oral_Presentations/6_c_Svalgaard_Contri.pdf

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Thank you northwind-adventurer.

7 hours ago, northwind-adventurer said:

Wherein we read, "Including the evidence from the recent heliospheric magnetic field [that also is a precursor of the cycle] leads to an estimate for SC25 approximately midway between cycles 20 and 24.

Midway between SC20 (156.6 Smoothed Max ISN) and SC24 (116.4 Smoothed Max ISN) gives 136.5, which does not even fall within The Panel's Peak Range prediction of 95-to-130.

So if the method is also the one endorsed & used by NOAA for early predictions, a question arises as to why 'The Panel prediction' was biased lower than Svalgaard's method? 

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Op 16/7/2019 om 04:58, theartist zei:

Marcel, over on the Solar Cycle 25 has already "started". thread, you state,

Do you care to elaborate further here on this point?

I don't remember where I read about that thought it was on SIDCs website somewhere but cant find it. Might have been a scientific paper. Could be mixing up things. Anyway, thought this graph was interesting showing the historical 10.7cm radio flux where short or prolonged periods of ''quiet radio sun'' do seem to tell a bit about the next cycle. Check also http://www.stce.be/news/417/welcome.html

Also a big thanks to northwind-adventurer for chiming in with his excellent post.

Figure1.png

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  • 1 month later...

The F10.7cm Flux is in the process of double-dipping!  This calls for an immediate slash in our forecast magnitudes. 

The forecast of the Sunspot Peak Range (in the first post to this thread) has been changed to reflect these events.

A press conference to announce this change in the SpaceWeatherLive Forum Forecast has not been scheduled.

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In the thread titled, Solar Minimum per SORCE SIM, I posted a measurement from a NOAA/NASA satellite.  It is a measurement of a specific frequency which indicates the level of magnetic activity at the photosphere where sunspots are generated as a result of magnetic activity.

We think such a measurement, if accurate, is very telling with regard to what is happening on the solar disc.  An obvious conclusion to be drawn from it is that the magnetic activity on the photosphere, at that wavelength, is greatly diminished from what is was in the last solar minimum.  That measurement is near-realtime, and we believe the very low magnetic activity on the photosphere measured during this SC24/25 transition will have direct bearing on the magnitude of peak sunspot activity in SC25.  This new evidence as presented consequently has major repercussions on the spaceweatherlive.com Forum's SC25 Forecast.

EFFECTIVE IMMEDIATELY: Based on the current magnitudes of the SORCE Solar Spectral Irradiance centered around ~677nm, as indicated by the SORCE SIM database, we are slashing our forum's forecast for the SC25 Sunspot Peak Range by 15 points.  

The forecast of the Sunspot Peak Range (in the first post to this thread) has been changed to reflect these events.

A press conference to announce this change in the SpaceWeatherLive Forum Forecast has not been scheduled.

 

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On July 16 (above), na states, "There is an accepted methodology called the solar cycle 'precursor method' scientists use when predicting solar cycles...the most successful theory so far..is the Solar Polar Fields Method."

Yes, I'm familiar with it.  Nonetheless, should not an up-to-date measurement which directly reflects the magnetic activity at the photosphere, and taken at solar minimum, hold more weight over a 'precursor method' that is based upon a 'polar field measurement' from a very limited number of observers?

na also states, "The solar polar fields method is also the one endorsed & used by NOAA for early predictions."

The critical measurement I posted in the cited thread is from the NASA/NOAA satellite taking Solar Spectral Irradiance (SSI) measurements and the Total Solar Irradiance (TSI) measurement which is so heavily bantered about by climatologists in the ongoing public AGW debates. If there is a public discussion on the integrity of those satellite measurements, I ask the kind viewer to step forward and point this author and the viewing public to such a discussion. To our knowledge, not one NASA scientist has publicly come forward remarking one way or another on the integrity of that measurement. Until that happens, we'll accept the data that NASA/NOAA are providing to the public as their public endorsement.

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54 minutes ago, theartist said:

On July 16 (above), na states, "There is an accepted methodology called the solar cycle 'precursor method' scientists use when predicting solar cycles...the most successful theory so far..is the Solar Polar Fields Method."

Yes, I'm familiar with it.  Nonetheless, should not an up-to-date measurement which directly reflects the magnetic activity at the photosphere, and taken at solar minimum, hold more weight over a 'precursor method' that is based upon a 'polar field measurement' from a very limited number of observers?

na also states, "The solar polar fields method is also the one endorsed & used by NOAA for early predictions."

The critical measurement I posted in the cited thread is from the NASA/NOAA satellite taking Solar Spectral Irradiance (SSI) measurements and the Total Solar Irradiance (TSI) measurement which is so heavily bantered about by climatologists in the ongoing public AGW debates. If there is a public discussion on the integrity of those satellite measurements, I ask the kind viewer to step forward and point this author and the viewing public to such a discussion. To our knowledge, not one NASA scientist has publicly come forward remarking one way or another on the integrity of that measurement. Until that happens, we'll accept the data that NASA/NOAA are providing to the public as their public endorsement.

There is an official NOAA presentation which goes through the NOAA Panel prediction for the previous Solar Cycle 24. It's worth having a look at https://www.swpc.noaa.gov/sites/default/files/images/u33/(1120) Biesecker Solar Cycle Update.pdf . It also mentions an 'early' expectation for Solar Cycle 25 - this document was last edited around 2016.

image.thumb.png.3b6f9876886428657bd6ac11dbe1dd8f.png

Even though it mentions the polar fields precursor method as one of the 'main precursors', there are several other methods used, including the 'Spectral' method, which in hindsight was slightly more accurate in predicting the SC24 sunspot number than the polar fields method. The difference was about 10 sunspots. But the spectral method does not seem to have predictions before the SC23 era. It might be worth using this method in hindsight to see if predictions stack up. Looking briefly at the F10.7 Radio Flux (one spectral measure) since 1950, the solar minimums from 1950-2000 had a very similar solar flux value (~70-75 average) though some cycles were weaker (SC20) when this method would suggest that SC20 should have been a bit stronger, possibly at least as strong as SC23. Then there was a significant dip in 2007-08 which led to a weaker SC24. The SORCE data could be useful also, but I can see that it only goes back to 2004...

I think the key thing about 'accepted method' is that the solar polar fields precursor method has been around for longer than the spectral method, and gained acceptance earlier. It can predict the upcoming solar cycles within a broad range time after time. While it is reasonably accurate, there may be newer and more complex methods nowadays that are more accurate (though they haven't gained acceptance over a long period). So over a long period the SPF precursor method has arguably been the most successful - even though for individual solar cycles other methods may have been more accurate individually. Also, it's worth noting that several 'Dynamo' models combine the solar polar fields, physics models and spectral measures. 

Furthermore, Leif Svalgaard himself was on the NOAA SC24 prediction panel. This panel was split 6-5 on a larger-smaller cycle, with the smaller one eventuating, and Leif Svalgaard at least correctly predicting it would be a smaller cycle using solar polar fields. In addition, the solar polar fields have now increased to an average value of 67, whereas around SC minimum in 2008 the max value was 61. (Can be seen on link in previous post)

Sello (2019) also provides a literature review of the current predictions and predictive methods for SC25 that can be seen here https://www.researchgate.net/publication/331110677_Solar_cycle_activity_an_early_prediction_for_cycle_25. He quotes "Among predictors class one of the most efficient and the first physical based precursor is the Solar Polar Field Precursor Method developed by Schatten, Scherrer, Svalgaard et al. [1978]" 

Based on this information, it seems the solar polar fields method was at least one significant factor in the NOAA 'Panel' forecast this year that has been made for Solar Cycle 25.

In any case, it's hard to predict exactly which method, panel or forecast will be the most successful for Solar Cycle 25 this early - though we can form an educated guess. As Sander said in another thread, we'll see what the result is in 3-5 years, and then there may be an even more accurate theory/method than the current ones.

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nw says, "Looking briefly at the F10.7 Radio Flux (one spectral measure) since 1950, the solar minimums from 1950-2000 had a very similar solar flux value (~70-75 average)..."

Actually, I would say that statement is not quite accurate.  Have you looked at all of the graphs I provided in the second post of the thread titled,  "F10.7cm Solar Minimum Analysis"?  Those graphs zoom in on a 3-year window roughly centered around the Solar Minimum Nadir for all seven solar minimums recorded since the data's inception.  If one look's carefully at that data (I plan to eventually update the SC24/25 transition graph), they might possibly conjecture that integrating (or even averaging) the data around solar minimum could provide a pretty good estimation of the following cycle's peak activity magnitude.

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Another predictive method worth looking into, and has been moderately successful over the years is the Geomagnetic Activity Prediction Method.

Ahluwalia (1998) https://www.researchgate.net/publication/253586281_The_predicted_size_of_cycle_23_based_on_the_inferred_three-cycle_quasi-periodicity_of_the_planetary_index_Ap

Basically, it uses an equation of geomagnetic activity smoothed 'AP index' at each solar minimum to predict the sunspot number at the next maximum roughly 4 years later.

image.thumb.png.fefe2dfb2c64e75413568aa426917944.png

image.png.0c763934b04a47f26918ee5ed3ff6585.png

image.png.63251e8415a7c9cf0bfe13106643010c.png

 

Using this method, one can predict the sunspot number for Solar Cycles 23, 24, and possibly even 25, for which the data wasn't available yet in 1998.

SC had a prediction of 119. The smoothed sunspot number in early 2000 (SC23 max) was 124.

Note that these sunspot numbers are the official Wolf (or international) sunspot numbers.

There was a revision made in 2015 increasing the entire sunspot series by a factor of 1.6 - That's lead to some confusion as all the predictions and measurements before then used the original Wolf numbers (not the revised). 

Using this method, we can try to predict SC24:

image.thumb.png.b07493718a649723363c715d9148a193.png

 

16.2(AP) - 27.

SC24 = 16.2(5) - 27       (SC sunspot minimum was in Dec 2008)

            = 54    (Actual number was 81)

That's quite a bit off, but it's a bit closer if you only count the first peak of the 'double peaked' solar activity. All the cycles measured SC23 and before in the paper had the solar cycle maximum in the first 'activity peak' - roughly 4 years after the SC minimum. Maybe we can make a tentative conclusion that this method is more accurate in predicting solar activity roughly 4 years from minimum, as opposed to the absolute maximum

For the Solar Cycle 25 prediction, we can just assume the sunspot minimum is where the most recent 'smoothed' AP value is - roughly 6.5.

That yields a prediction of 78 ~ meaning in 4 years according to this method the cycle will be similar strength as the one just gone - in line with what the NOAA 'Panel' and the solar polar fields method predict. But the solar maximum might even be in 6 years, and it could follow the SC24 trend of having the second solar activity peak stronger than the first one. 

 

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FWIW, the AP index minimum tends to lag the sunspot minimum by 1-1.5 years, so the current values might not be applicable in time. I’m willing to bet the AP index minimum will not be reached until 2021.

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Great stuff, folks!👍  Let's kick this around some more, and maybe we can eventually come up with a consensus we are all comfortable with.

I wish to now quickly drop something here that I think is worthy of much deeper consideration.  Below is a snapshot of a magnetogram which I. Kitiashvili presented in her presentation (which I linked to on the other forecast thread ) :

1866919544_Snapshotofmagnetogram.thumb.jpg.e6e7b27af2412b646513bab24798672f.jpg:

Below I've added some some annotations to the same magnetogram:

1296580493_Magnetogramannotated.thumb.jpg.dc31f187bcf52fe0ecdab49420fb98b7.jpg 

 

Some things I quickly annotated are:

  1. The Red vertical lines are the Solar Minimums.
  2. The slope and character (e.g., their length) of the drawn lines (these are subject to some human fudging).
  3. The location of the bifurcation points, and their character (e.g., the angles created between the bifurcated lines).
  4. The intensity of magnetic poleward flow.
  5. The intensity of the Magnetic Poles, particularly at Solar Minimum.

 

Reflecting upon the top (non-annotated) graph, here are some things that seem to stick out:

  • (A) SolarCycle24 appears significantly magnetically weaker, overall, compared to the other cycles.
  • (B) The intensity (magnitude) of poleward magnetic flow during SC24 was considerably less compared to the other cycles.
  • (C) Compared to the previous cycles' solar minimums, the current magnetic strength at the poles (particularly the north pole) appears drastically weaker.

 

Agree or disagree?  Comments?

42 minutes ago, theartist said:

Comments?

The first comment that comes to mind is that the measurements between the cycles were not taken with the same satellite, and thus, possibly prone to calibration inconsistency.  Well, hopefully the scientists have carefully taken that into account (a reason they get paid the 'big bucks', right?  🤣).  

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na says, "Using this method, we can try to predict SC24...

16.2(AP) - 27.

SC24 = 16.2(5) - 27       (SC sunspot minimum was in Dec 2008)

            = 54    (Actual number was 81)

-------------------------------------------------------------------------------------------------------------------------------------------------

The first thing to clarify, in using such a method, is what the definition is of the "Annual Mean Minimum Value of Ap".  You used "5".  How did you arrive at that number?

 I looked at his paper, and after checking, I don't think he is always using the yearly averages found here:

Ap yearly data.jpg

 

For instance, in Table 1 of that paper, here are the Ap yearly mean minimums he used to support his theory:

Ap table.jpg

But the data I just linked to has these values:

  • 1934.......7.2
  • 1945.......10.4
  • 1955.......11.3
  • 1965.......7.7
  • 1977.......11.9
  • 1987.......11.0
  • 1997.......8.4

Some of the numbers are right on, but there are discrepancies in some of them, too.

The other major point that you seemed to have missed in your calculation is that in the paper's method, the year AFTER solar minimum is used for the mean yearly Ap. From the data I linked to, the yearly mean Ap for 2009 was a value of 3.9 (not 5).

 

(to be continued)

On 10/23/2019 at 12:47 AM, Philip said:

FWIW, the AP index minimum tends to lag the sunspot minimum by 1-1.5 years, so the current values might not be applicable

Exactly.  I previously posted the following figure over on the the thread titled,  Ap & aa Indices and Solar Minimum:

150319940_Apindex.png.5f39323c18d8a8b50dbfc993477677bc.png

Looking at that graph, the value of Ap Index one year prior to the the SC23/24 Solar Minimum Nadir (SMD) is ~8.2.  Suppose, for instance, the SMD for the SC24/25 transition is eventually found to be in Dec 2019 (exactly 11 years after the SC23/24 SMD).  According to that graph, the value of Ap Index one year prior (in Dec. 2018) is ~7.2, which is lower than the setup for the prior minimum; meaning, the Ap Index for the SC24/25 transition could possibly end up being much lower than where it currently is, and possibly lower than the lowest point in the SC23/24 transition.

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  • 1 month later...
On 7/15/2019 at 7:58 PM, theartist said:

Marcel, over on the Solar Cycle 25 has already "started". thread, you state,

Do you care to elaborate further here on this point?

From the unusual perspective, a short cycle would fit in well with what I suspect happens to the West Coast flood cycle as it is driven by the solar cycle.  I now see that it ranges from 9 years exactly, 10 years exactly, and 11 to not quite 12 years at times. Examples of 9 year floods were the 1950s/60s, followed by 11+ years 1970s into 1990s, and lastly back to 10 year exact since 1996/97. But the only way that this can work is if the sun has the occasional short cycle to reset the pattern. Otherwise the West Coast flood pattern would melt away into just another chaotic weather pattern.

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Hi Earl, welcome to the forum.  Honest scientific inquiry and analysis is welcomed here.  Please do try to flesh out an explanation as to why you think a 'double peak' is mandatory and share (even if you don't have it completely figured out).  

I think we should try to frame a basic forecast, and then work from there. By 'basic', I mean a statement to the effect of whether SC25 will be either (1) biased weaker, (2) equivalent or (3) biased stronger. I think "strength" of the cycle can be framed both like it is done currently by the panel, looking at the 'monthly smoothed SSN, but I think a couple of more definitive (and thus useful) parameters of 'strength' should be included, like strength in terms of the total cycle area integrated under the F10.7cm curve.  The 'basic' could then be followed with a more granular explanation of 'strength', like 'double-peaked, over X-X time-period, making the forecast more utilitarian (though more difficult to predict).

On 12/14/2019 at 6:29 PM, goldminor said:

Otherwise the West Coast flood pattern would melt away into just another chaotic weather pattern.

If I'm not mistaken, I think there is an analogous discussion along these lines amongst solar physicists with regard to what dynamo theories would explain the ability of the sun to come back out of a Grand Minimum scenario. 

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2086630177_ScreenShot2019-12-11at4_06_33AM.thumb.jpg.a727797d86eb698f1be58bddd3a1082c.jpg

(source of graph)

In consideration of the above graph, if the Northern Hemisphere has been waiting around for the Southern Hemisphere to get ready, and then they both take off simultaneously (unlike in SC24), then it is possible that the total peak magnitude could be considerably higher than SC24, even if the total energy under the F10.7cm curve for SC25 turns out less than SC24.

That is to say, if the peak of the North lays on top of the peak of the south, then they would add up to produce a high Total peak.

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On 12/16/2019 at 6:45 PM, theartist said:

In consideration of the above graph, if the Northern Hemisphere has been waiting around for the Southern Hemisphere to get ready, and then they both take off simultaneously

If this happens, then it very well could change the complexity of the situation.  Quickly ruminating about the 'what-if' ramifications of this happening, leads me to think there actually could be a possibility of Solar Minimum Nadir happening in 2019, if the expected high-latitude (i.e., above the critical + 32deg) dipole structure(s) happen in both hemispheres, in quick succession.  In such a scenario, the total rise of the cycle would be expected to be more rapid than when the hemispheres are rising at different rates.  Such a scenario, in light of the Waldmeier Criterion, could give us a 'stronger cycle', in terms of the smoothed peak of SSN, even if it were to produce, overall, similar active region activity to that of SC24.

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