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theartist

Synoptic Magnetograms; SC24 Minimum Forecasting

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I open this thread with a huge shout-out THANK YOU to those organizations that put their data out there, allowing the citizen scientists to observe/review it right along with the professionals.  I want to thank the National Solar Observatory Integrated Synoptic Program, particularly, for this exercise.

(to be continued)

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I apologize.  My analysis is taking longer than I expected, and I want to be somewhat thorough.

Therefore, in order not to be rude, I'll open this up to the community, and, at the risk of their servers crashing, let you all have-at-it as well.

I'm thinking that this data, together with our other findings, will be a big puzzle-piece in helping determine where the Solar Minimum (Nadir) is at.  And as you might suspect, when that gets nailed down, then other dominoes will fall (and we then should be able to come up with a more confident forecast).

Here it is folks, here is where I've spent the last few hours (and I think I have a ways to go):

https://gong2.nso.edu/products/scaleView/view.php?configFile=configs/quickreduce.cfg

To team-member, "The Norwegian", I hope you can take a look.  I think you'll understand what I'm suggesting.

 

Background Info

Recently on the thread titled, "F10.7cm Solar Minimum Analysis",  "The Norwegian" stated, "I bet 2019 will be one year with over 280 days without sunspots. 2020 will have not less that 265-270 spotless days :)".  The following graph depicts that forecast:

336315077_SpotlessDays.thumb.jpg.07128dd130dec2170624f1e9fdd6dcb5.jpg

I too have considered similar possibilities, although not as firm in conviction on the "Spotless Days" numbers, since it depends on where Solar Minimum (Nadir) falls.  One possibility we have kicked around is it falling roughly 11 years (to-the-month) since the previous one, and that is depicted in the "Scenario C" graph placed earlier in that thread (repeated below):

ScenarioC.thumb.png.8453b32597b19bdfaca9acbf848a50c8.png

 

(to be continued)

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QUICK UPDATE: There is a lot of very interesting solar science stuff that can be said after actually looking at a 'scrolling magnetrogram'.  I've spent several hours (and could spend days).  SDO is absolutely INCREDIBLE, but one of its unfortunate limitations is that its imagery data only goes back to (roughly?) 2010; we therefore do not have SDO imagery from the last solar minimum epoch to compare with the current solar activity.  (Maybe(?) there is a repository for HINODE satellite imagery, but if so, I haven't yet found a convenient online resource to get to it.)  However, I stumbled upon these 'scrolling magnetrograms' yesterday, and their power lies in providing a convenient record of the previous solar minimum which we can compare alongside current activity.

From my review of the 'scrolling magnetrograms' so far (hopefully some of you will analyze the data and come to similar conclusions independently), I conclude that we have not yet crossed the Solar Minimum 'Nadir' [which as you know, is the official scientifically defined "START" of the next 11-yr Schwabe sunspot cycle.  The "START" of the solar cycle is NOT "onset" (per K. Strong's term, "Strong & Saba, 2009"), which typically occurs much later after Solar Minimum 'Nadir'].  Since we most likely have not yet crossed the Solar Minimum 'Nadir', pinpointing its location into the future from the 'scrolling magnetrograms' is, therefore, a more difficult problem.  My current (cursory) conclusion is that this cycle's Solar Minimum 'Nadir' is ~11yrs 3-4 months (i.e., ~11.25 years) after the SC23/24 Solar Minimum 'Nadir' of December 2008.  

(to be continued)

 

Edited by theartist
Added the Strong&Saba reference.
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The differences between the two cycles, primarily the relative magnetic weakness in the later cycle, IS observed in the magnetrograms.  Consequently, the implications on the bottoming-out of sunspot activity require careful consideration.  For example, in the extreme case, if much fewer sunspots manifest in SC25 (i.e., Bright-Points in the corona occurring generally without sunspots on the photosphere) then the 'Nadir' will get pushed further out in time, just as it was with SC23, producing a long ‘delayed’ cycle.  (Eventually, however, over several cycles, there is a “regression to the mean” in solar cycle length, averaging out to be ~11.x yrs.)  But the quick conclusion we can draw here is that since the ‘Nadir’ has likely not passed, ’The Norwegian’ forecast on spotless days looks quite plausible.

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The following two tables evaluate the monthly sunspot numbers for the last seven cycles; the Solar Minimum 'Nadir' (SMN) is lined up across the board for all seven cycles. In Table 1, SC24/25 is lined up such that its SMN will fall exactly 11 years after the SC23/24 SMN. In Table 2, SC24/25 is lined up such that its SMN will fall exactly 11.25 years after the SC23/24 SMN. (Note, the data in these tables is the 13-month smoothed monthly total sunspot number found here: http://www.sidc.be/silso/datafiles.)

408451120_Solarminimum11yrs.thumb.jpg.add9de246355f41c4d6e4e7a0cee7072.jpg

Table 1.  The SC24/25 is lined up such that its SMN will fall exactly 11 years after the SC23/24 SMN.

 

1858070281_Solarminimum1125yrs.thumb.jpg.f27de3d3798945158a05c06a51574108.jpg

Table 2.  The SC24/25 is lined up such that its SMN will fall exactly 11.25 years after the SC23/24 SMN.

From evaluation of the trends in each table, either scenario indicates the sunspot number at SMN for SC24/25 is eventually going to be lower than the SMN value of 2.2 for SC23/24.

A shift by just 3 months dramatically affects the ratio of the previous cycle sunspot numbers to the current cycle sunspot numbers, particularly when close to the SMN.

Edited by theartist
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On 11/7/2019 at 11:09 AM, theartist said:

The "START" of the solar cycle is NOT "onset" (per K. Strong's term, "Strong & Saba, 2009"), which typically occurs much later after Solar Minimum 'Nadir'.

The following figure is from the K. Strong, et.al. paper titled, "A new approach to solar cycle forecasting":

1490112258_onsetsx.thumb.png.e5940f2261edeabd5b164b3b7a0db4f1.png

 

I've annotated the figure with red vertical lines indicating the respective Solar Minimum Nadir locations.  Per the definition of "onset" according to that paper, they occurred after Solar Minimum Nadir (SMN), as seen in the above figure, as follows:

  • Cycle 21 "onset"...~6 months after SMN;
  • Cycle 22 "onset"...~6 months after SMN;
  • Cycle 23 "onset"...~12 months after SMN.
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In light of the abnormally long solar minimum period prior to SC24, it would be nice to find out how it compared with the above data, and find out where the "onset" of SC24 occurred relative to SMN at the end of SC23.  Possibly a clue is found in an earlier K. Strong paper, wherein the observed 'quick rise in activity' was originally termed, "the step"

The following figure is from the Saba, Strong, & Slater paper titled, "Can we predict when the next solar cycle is about to take off?":

1272097649_x-rayonset.thumb.jpg.a600a28597bdb1b0a95af12d42d4e716.jpg

I've annotated the above figure with a red vertical line to show where the SMN occurred, and a black vertical line (at August 1997) to point out where the paper implies "onset" or "the step" occurred.  I also point out in the figure that there are individual data points representing X-ray spikes prior to the "onset", as a cautionary note; observing those spikes real-time might leave one with a false impression that the big "onset" has arrived, only to find out later that is not the case.  

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The following figure is from a recent paper titled, "What the Sudden Death of Solar Cycles Can Tell Us About the Nature of the Solar Interior", by S. McIntosh, et. al.:

1056129595_SC23terminator.thumb.jpg.e4779a97ddb904bb8a921224b025b31b.jpg

I have annotated the graphs to show where SMN occurs, and to highlight "Pre-activity".  The red dotted vertical lines are what the authors term as "terminators". Note the "terminator" placed in 1997, at the beginning of SC23, lies very very close to the "onset" for SC23 determined by K. Strong, et.al. (2009).  

There are two interesting takeaways from this figure:

  1. For the case of a very deep and long solar minimum period, the "terminator" occurred over two years after SMN.
  2. Significant "Pre-activity" is observed to have occurred in both cycles, again cautioning for the possibility that such activity, when it is happening, is not necessarily a confirmation that an "onset" of vigorous activity, immediately to follow, will occur.

 

(to be continued)

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The 'scrolling magnetograms' show a progression of activity in the months leading up to the Solar Minimum Nadir (SMN) in the SC23/24 transition epoch.  We can see notable changes occurring within one-to-two Carrington Rotations during those months of progression.   It is also observed that significant attributes occurred very near to--i.e., within one Carrington Rotation--the SMN in Dec 2008, and we think these quite possibly can act as indicative markers for the coming SMN in the SC24/25 transition.  

The SC24/25 transition is turning out to be a long, slow and weak solar minimum epoch, very similar to that of the SC23/24 transition.  The notable changes and progression of activity we see in the 'scrolling magnetograms' of the SC24/25 transition are similar to what we observe in the SC23/24 transition.  We therefore expect to similarly see the indicative markers near the coming SMN, to act as chief attributes heralding the arrival of the official START of Solar Cycle 25 (to be confirmed, officially, several months later from the tallying/averaging of the sunspot numbers).

In our next installment, we'll cover some of the attributes and changes observed in the 'scrolling magnetograms'.

 (to be continued)

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Method of Analysis and Findings

The objective in this first study of the 'scrolling magnetograms' is to evaluate the character of the 'magnetic structures' in order to elucidate, with as much precision as possible, the temporal location of the upcoming Solar Minimum Nadir (SMN) in the current SC24/25 transition.  (Not all of the 'magnetic structures' of interest produce sunspots and/or are given an Active Region designation by NOAA.) The 'magnetic structure' attributes of prime concern for this first study are:

  1. their intensity (determined by their brightness, and solidity or diffusivity);
  2. their size (i.e., area);
  3. incidences with complete lack of 'magnetic structures' in the scrolling window, herein termed a 'blank page';
  4. their polarity;
  5. their latitude.

The last attribute, latitude, is determined to be the chief attribute that will signal close proximity to the SMN.

The following two figures are annotated to highlight features in the magnetogram scrolling window, in order to help explain the method of analysis and features of interest.

464001446_Manetogramattributes1.thumb.jpg.d117c778469bca8abe1dd7dbe050c0e5.jpg

                 Figure 1.  The 'Critical Latitudes' are at +/- 32 degrees, and +/- 42 degrees. Within one-month on either side of the month of SMN for the SC23/24 transition (i.e. Dec. 2008), some magnetic structures fell at latitudes higher than the 'Critical Latitudes'

 

1790743916_blankpageexample.thumb.jpg.78da7ddbb1f82e26361ab8da00746954.jpg

                 Figure 2.  We term a complete window without a single 'magnetic structure' as a 'blank page'.

 

The applet at the NSO gong website allows a maximum scrolling window length of 62 days. This is a good length, covering a little over two Carrington Rotations, allowing a many-month evaluation to be broken down into useful chunks (i.e., not too big or too small).  When performing an analysis covering many months, it is helpful to have many browser tabs open, each loaded-up with scrolling windows successively incremented in time, enabling one to quickly go back and forth comparing activity in different epochs. (For evaluation of more recent data, the "Image increment", circled Red in Figure 1, can be set to the value of 6, which will give a number of magnetogram images comparable to the files recorded back in the SC23/24 transition.)

Here are our findings and conclusions to this first study:

  1. The first mag-structure in the SC23/24 transition that fell above a Critical Latitude occurred ~1.5 months before the SMN (i.e., first appearing on Oct. 19, 2008).
  2. Within one month on either side of the SMN of the SC23/24 transition, eight (8) 'magnetic structures' fell at higher latitudes than the 'Critical Latitudes'. All of those structures were easily discernible, and lasted more than a day or two, with most of those lasting many days in duration.  A subset of four of those mag-structures fell on or above the +/- 42 deg Critical Latitude. These four mag-structures, falling at Critical Latitude of +/-42 deg (or higher), occurred within +/- one (1) month of the SMN. The list of all the mag-structures that fell above Critical Latitudes (at least as far out as May 2009) is found in Table I below. Figures 3-7 show the locations of the first nine of those structures.
  3. In the current SC24/25 transition, to date, a total of zero (0) mag-structures (lasting more than a day or two) have fallen above the Critical Latitudes.
  4. Based on our evaluation of the mag-structure's occurrence trends in the scrolling magnetograms, we forecast SMN will occur in February 2020, +/- one (1) month

 

828172677_MagStructuresforSC2324.jpg.4d06e2391491188bdee32858de32a60f.jpg 

     Table I.  List of Mag-Structures falling above the Critical Latitudes in months immediately before during and after the SMN of the SC23/24 transition.

 

4226670_1-4criticalspots.jpg.1e098f236299ae2afb73883c3e260e4c.jpg

       Figure 3.  Location of mag-structures 1-4 listed in Table I.

 

698998332_5-6criticalspots.jpg.33d62abc666eb467347c6965c95b1c78.jpg

       Figure 4.  Location of mag-structures 5-6 listed in Table I.

 

1921204888_6-7criticalspots.jpg.18c2d4890c1b53e199d3c7038d996822.jpg

          Figure 5.  Location of mag-structures 6-7 listed in Table I.

772843775_8criticalspots.jpg.7a40abe26995901772797710fa404568.jpg

       Figure 6.  Location of mag-structure 8 listed in Table I.

 

1543741972_9criticalspots.jpg.8343f5b85eba69e8e00e0a7cfb8ec82c.jpg

       Figure 7.  Location of mag-structure 9 listed in Table I.

 

We now challenge the reader to look at the scrolling magnetograms for themselves to see whether or not they agree with this forecast.

 

10 critical spots.jpg

Edited by theartist
Added explanatory note about the "Image increment".

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Method and Findings

The objective of this first study of the 'scrolling magnetograms' was to come up with a more precise forecast for when the Solar Minimum Nadir (SMN) will occur in the SC24/25 transition.   

Features of the 'scrolling magnetograms', and critical attributes of the magnetic-structures that were evaluated, are highlighted in Figure 1 and Figure 2.

1939628258_Manetogramattributes1.thumb.jpg.e315379995795983d87a42ce0329ece7.jpg

       Figure 1.  Features of the 'scrolling magnetogram' applet and important attributes of the mag-structures are highlighted in this figure.

The 'scrolling magnetogram' applet at the NSO gong site allows a maximum duration of 62 days, i.e., a little over two Carrington Rotations (CR).  This is a convenient size to break a problem up into good size chunks (not too big or too small) when evaluating a multiple-month epoch up to a year or longer in length.   

This study evaluated the following attributes of the mag-structures, particularly how they changed over the progression of solar minimum:

  1. their polarity;
  2. their intensity (i.e., their brightness and apparent image 'solidity' versus 'diffusivity');
  3. their size (area);
  4. periods, of at least one CR in duration, when no mag-structure appeared in the scrolling window, termed 'blank pages', an example of which is shown in Figure 2; 
  5. their latitudes.

 

1682972875_blankpageexample.thumb.jpg.cee43b7fc4d24435e3fa776d8cb1fe0a.jpg

       Figure 2. A 'blank page' is the occurrence of no magnetic-structures (of sufficient size-of-interest) in the scrolling window.

 

It was determined in this study that few mag-structures occurred above the Critical Latitudes of +/- 32deg, and particularly above +/- 42deg, during the SC23/24 transition. Those that did were primarily centered around the (Dec. 2008) SMN; their occurrence was a prime indicator that the SMN of SC23/24 was impending.  Table I lists all the mag-structures found to occur above the +/- 32deg latitude for the SC23/24 transition.  A subset of four (4) of these occurred on or above the +/- 42deg latitude. All four of those occurred during a 3-month window centered around the SMN.   

1020589240_MagStructuresforSC2324.png.a7cda7cce4d6d7cfb537510d5d5b0f0b.png

            Table I.  List of mag-structures that fell above the Critical Latitudes during the SC23/24 transition.

Figures 3 thru 7 display mag-structures #1 thru #9 listed in Table I.

1551354884_1-4criticalspots.jpg.a51b22e30e3ef504a76bbf01d3d689da.jpg

            Figure 3.  Mag-structures #1 thru #4 from Table I.

 

552748930_5-6criticalspots.jpg.e14a80607dcc5c20cfde50593d162fa2.jpg

            Figure 4.  Mag-structure #5 and #6 from Table I.

 

1501094601_6-7criticalspots.jpg.9893f398f31911b745e28f64d96bddbf.jpg

            Figure 5.  Mag-structure #6 and #7 from Table I.

 

338194202_8criticalspots.jpg.0624e900a142b7ae5c26ad7067e29845.jpg

            Figure 6.  Mag-structure #8 from Table I.

 

630930518_9criticalspots.jpg.6a13b965cbc6b9f06b4e175f6c7c7132.jpg

            Figure 7.  Mag-structure #9 from Table I.

 

Conclusions

  1. Similar temporal trends of mag-structure activity, between the SC23/24 and SC24/25 transitions, is observed in the 'scrolling magnetograms'. 
  2. All mag-structures on or above +/- 42 deg latitude occurred within one (1) month of the SC23/24 transition's SMN.
  3. To date, a total of zero (0) mag-structures have occurred above the Critical Latitudes in the SC24/25 transition. We consequently conclude the SC24/25 transition's SMN has not yet arrived.
  4. From our evaluation of the 'scrolling magnetograms' we forecast the SC24/25 transition's SMN will likely occur within a 3-4 month window centered around Jan. 2020.
  5. Possibly, with further study of the 'scrolling magnetograms, in combination with our other findings, higher confidence in our forecast of SC25 can be achieved.
Edited by theartist

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UPDATE:

In Table I above, the "Duration" values are not accurate, and what I was calling "42deg latitude" may actually have been "40deg latitude" (this is due to my incomplete grasp of how the 'scrolling magnetograms' were assimilitating data).  But that really is not important at this point.  If the photospheric mag-structures last longer than a few days, and are of 'sufficient' size, then that is what makes them of 'significance'.  (Note, the adjectives 'sufficient' and 'significance' are to be understood within the context of this discussion.) I'm now in the process of searching what magnetograms are historically available (there are disparate databases at various places online that abruptly end in time), in order to cross-correlate the data so that we will have a decent idea of what to look for, going forward.

Make no mistake, what we have uncovered here is quite significant in providing an important marker that will herald the point in time at which Solar Minimum Nadir will occur. This is a significant finding, quite-so, to the extent that I haven't found a source in the scientific literature, or elsewhere, where solar physicists are discussing it.  Make no mistake, "onset" or "terminator" or other nebulous and sometimes misused terms are NOT the official "START" of a solar cycle.  The commonly accepted scientific definition of a solar cycle's "START" is where Solar Minimum Nadir occurs, and I now think I have come across a marker, found in the magnetograms, that will tell us when the "START" of SC25 is impending.  Furthermore, these mag-structures appear relatively quickly, within one-two Carrington Rotations, such that we do not need to wait for some nebulously defined "onset" in the future to see a "quick-change" marker that signifies the new cycle. Another important point is that we are looking specifically for magnetic-structures above the Critical Latitudes, rather than bright-points or prominences or 'jets' above the Critical Latitudes. It is the occurrence of photospheric magnetic-structures above the Critical Latitudes that provides a strong indication of underlying dynamo magnetic activity, and the mag-structures of 'significance' manifested in only a relatively few, but quite-telling, appearances at the juncture of the Solar Minimum Nadir in the previous solar minimum transition.  This is in contrast to more flighty activity, like bright-points or prominences, which occur long before and long after Solar Minimum Nadir, and quite frequently above the Critical Latitudes, and are consequently too numerous to be able to pinpoint the Solar Minimum Nadir, getting lost in the 'noise'. 

For the purposes of cross-correlation, solarmonitor.org is one source offering the convenience of quick data access, though it limits us to what they choose to present. Nonetheless, we will try to work with it.  Our first step, then, is to compare what the mag-structures, called out in Table I above, look like at solar monitor.org.

Below is #1; notice it it extends significantly above +32deg latitude:

159122386_120081019_124701.thumb.jpg.ec7967519c781a0b17430e3a7c7325e3.jpg

Next is #2; BINGO, it is much more intense, and significantly above 32deg latitude:

1815327489_2_20081101_111501.thumb.jpg.075d401d3bd2c2550a89fc31e9c1778f.jpg

Edited by theartist

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The next image shows #3, #4 & #5.  #4 morphed into #5 and they were located very close to each other.  A very significant finding in this image is that #3 looks much more diffuse and inconsequential than when it appeared in the 'scrolling magnetogram' (i.e., shown in Figure 3 in previous posting above). Its area did extend up above 40deg latitude (in the southern hemisphere), but because it is so diffuse, it is a type of structure that may be overlooked in a real-time, day-to-day survey:

1921626481_345_20081111_160301.thumb.jpg.40e1cbbe704fa3dd2912d74d706d001f.jpg

Edited by theartist

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The next image of #6 is VERY interesting, because when compared to the 'scrolling magnetogram' image (Figure 5 above), the MDI Magnetogram at solar monitor.org looks like it somehow got flipped upside down:

1074284118_6_20081129_124701.thumb.jpg.e24e5047af019a771f5a2c444cc63fbc.jpg955486376_6isflipped.jpg.786f146a3fd6b3191ae1c347d61926e0.jpg

The next image of #7 indicates that this image (or the 'scrolling magnetogram' imagery) was also flipped upside down.  I highlighted a 'Marker Feature' in the image, to compare with the same feature highlighted in the 'scrolling magnetogram', as a point of reference.

1086440532_7_20081209_111501.thumb.jpg.f007d33b152e80a78d259eff5b05088b.jpg1508524340_7isflipped.jpg.54f640f2d3b38429001106c661bd1572.jpg

The next image of #8 shows it to be so very diffuse and faint that it doesn't even show up, like it faintly did in the 'scrolling magnetogram'. 

2085641968_8_20090103_222800.png.5b1f79b7908180084483a06a8e7cda74.png

 

Next is the image of #9:

1762220713_9_20090122_204000.jpg.5fcb42b292387a395b15428fe0d62d8d.jpg 

Edited by theartist

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Dear reader, if you have read this thread and understood it, do you now have a greater clarity on what is a likely outcome for the next cycle?  Will you have greater clarity when you understand where the Solar Minimum Nadir is located?  Has it already passed?  NO, per the findings laid out in this thread, it is yet to happen in the future.  How far into the future? One month? Three months? Another year to wait?

What is the first thing to look for, to deduce the location of the Solar Minimum Nadir?  It is a photospheric magnetic structure above 32deg latitude, in either hemisphere.  We do not expect Solar Minimum Nadir to occur until that happens.  

Following the first manifestation of a 'significant' (in size) photospheric magnetic structure (mag-structure) above 32deg latitude, in either hemisphere, we then expect Solar Minimum Nadir to occur within the 1-3 months thereafter.

Edited by theartist

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Okay kind reader, since you now understand what marker to look for which will signify that Solar Minimum Nadir is imminent (i.e., within 1-3* months of the first appearance of such marker), your next question might be, "Why do I think Solar Minimum Nadir will likely occur no sooner than January or February 2020, give or take a month?"  

The answer to that question is found in other information (I have not yet discussed in detail) that appears in the 'scrolling magnetograms', like the 'blank page' mentioned earlier in this thread (see Figure 2 above).  

Do you recall the thread titled,  "Multi-Rotation Persistent Magnetic Structure"?  That large photospheric magnetic structure discussed in Case 2 of that thread was quite often trans-equatorial (it existed at low latitudes and extended across the equator).  Another quite significant thing we have learned from our review of the magnetograms from the SC23/24 transition is that prior to and during the month of Solar Minimum Nadir,   in the months prior to the occurrence of 'significant' mag-structures above the Critical 32deg Latitude, the solar disk cleared out all 'significant' (in size) mag-structures at the equator!

[*Note, in the SC23/24 transition, the month of Solar Minimum Nadir was ~1.5 months after the first mag-structure appearance above the Critical 32deg Latitude.]

Edited by theartist
Clarified accuracy of statement about mag-structures reduced at equator.

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That is a very interesting analysis.  I look forward to seeing whether or not it happens as you say.  How does this influence your thoughts on the max for CY-25?

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5 hours ago, theartist said:

prior to and during the month of Solar Minimum Nadir, the solar disk cleared out all 'significant' (in size) mag-structures at the equator!

Whoa, hold on, all were completely cleared out?!? Look at the image from 11 Nov. 2008:

11-nov.thumb.jpg.cc0f0e23ce593ad076e499b7670658a0.jpg 

My point is that generally, in the few months prior to when mag-structures appeared above the Critical 32deg Latitude, the amount of mag-structure activity at the equator was noticeably reduced.  The reader can verify that by checking for 'blank pages' in the 'scrolling magnetrograms'.  The last 'significant' photospheric mag-structure to occur near the equator, prior to the one highlighted in the above 11-Nov-2008 MDI Magnetogram, occurred on 21-Jun-2008 (next figures):

472310492_jun21magnetogram.jpg.e329736524032a21551e528fb68baeca.jpgsmdi_maglc_fd_20080621_212800.png.07129ba45ad6c9431aa67d88f949e1f1.png

I will go back and edit my statement.

Edited by theartist

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The figures below reveal the progression over time, in recent months, of mag-structures close to the equator (i.e., between +/- 10deg latitude).

1930767079_May919.jpg.1ab3ae0d72a74cb8b9361f68538e2164.jpg598569132_Jul519.jpg.9f3324f8db2d0a5acbf62d1113fa4e6b.jpg1934265952_Aug819.jpg.4be8f4c7752191cd71577f18db01f901.jpg1249727713_Sept1319.jpg.e8f7bde2689997c3ca43806d149043d6.jpg1557671680_Oct719.jpg.1d6b58ae13ad685f18fcb7149938b985.jpg525585537_Nov719.jpg.07ffb050e909cf3d6f2de3070a9009a8.jpg

 

11 hours ago, Dennis Wingo said:

That is a very interesting analysis.  I look forward to seeing whether or not it happens as you say.  How does this influence your thoughts on the max for CY-25?

Welcome to the forum, thank you.

I want to eventually investigate the magnitude of SC25 again more closely.  My current view has been that SC25 will be maybe as strong, but biased weaker, than SC24.

However, my most recent findings posted in this thread today, in which I compare photospheric magnetic-structure activity near the equator between the SC23/24 and SC24/25 transitions, are rather sobering. In the SC23/24 transition, there was zero (0) mag-structure activity at the equator for four (4) months before a magnetic structure appeared above 32deg latitude, and then SMN occurred two (2) months later. In the current SC24/25 transition, we still had mag-structure activity (albeit small in size) near the equator in this current month of November. Does that suggest SMN might still be at least six (6) months away?!?   If that were the case, a comparison of the sunspot number trends (from Table I and Table II earlier in this thread) between the two cycles implies SC25 could be significantly weaker than SC24.

Edited by theartist

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14 hours ago, theartist said:

a comparison of the sunspot number trends (from Table I and Table II earlier in this thread)

I'm sorry, I'm referring to the tables first posted to this thread on Nov. 8, labeled Table 1. and Table 2.

Edited by theartist

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17 hours ago, theartist said:

The last 'significant' photospheric mag-structure to occur near the equator, prior to the one highlighted in the above 11-Nov-2008 MDI Magnetogram, occurred on 21-Jun-2008 (next figures)

I again went back and reviewed the 'scrolling magnetograms' of 2008 to see if there were any small regions (near the equator) during the drought interval between 21-Jun and 11-Nov that I may have previously rejected as insignificant.  The biggest and most enduring of the smallish mag-structures is circled in the figure below:

401511940_Oct908.jpg.364ab421469fb057a8ce69669443bbb4.jpg

Here is what it looked like in the MDI Magnetogram:

941394893_9Octequator_20081009_160000.jpg.c90184be8de80905053ea6f48c4c272e.jpg

That little area fell on 9-Oct, 10 days before the first high-latitude area appeared on 19-Oct.  

Edited by theartist

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