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Post by duwayne on May 15, 2022 16:50:03 GMT
Leif Svalgaard’s Cycle 24 maximum sunspot number prediction was right on the mark and his Cycle 25 prediction is looking good so far. I set up this thread to try to describe my understanding of his method in simplified terms and why it makes sense to me and its limitations.
We have toy magnets which permanently hold their magnetism. They are made by putting a container filled with magnetically sensitive particles in fluid state into a magnetic field where they align to form a magnet. They are then cooled/compressed into a solid form so they retain the magnetism.
The sun is a fluid with particles of magnetically active materials. There is a time in the solar cycle when the magnetic materials become lined up in a “north/south” pattern. The solar poles show a high level of “magnetic charge”, one pole is positive and the other is negative. A magnetic field results.
The sun is fluid and thus no permanent magnets are formed. Magnetically sensitive globs of particles swirl through the polar magnetic field and magnetic blobs or ropes are formed. Magnetic “flux” is thus transferred from the polar field to the ropes and the strength of the polar field is accordingly reduced and the charges at the poles drop.
These ropes then circulate within the sun's interior and some make it to the sun’s surface. If the rope is sufficiently charged (1500 gauss or higher), it will appear as a sunspot group.
Over a 5 ½ year period from peak solar field, the ropes will pick up much of the polar magnetic flux and the polar field will disappear. Then the process will reverse and the poles will change signs and grow by taking the flux back from the ropes.
Svalgaard argues the maximum number and strength of the flux in the ropes is the result of the strength of the poles at their maximum some 5 ½ years earlier. And the sunspot maximum is a function of the strength and number of ropes.
When sunspots are low the polar strength is high and vice versa.
More to follow…… |
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Post by code on May 15, 2022 22:17:58 GMT
I reached out, hopefully he will chime in. Anyone have contact a history with him?
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Post by code on May 15, 2022 22:19:47 GMT
There is growing acceptance of the suggestion by Schatten et al. (GRL 5, 411, 1978) that the Sun’s polar fields during a few years leading up to solar minimum is a ‘seed’ for the next solar cycle, being transported to and amplified in the interior by the solar global dynamo. If so, Predicting the size of the next solar cycle then comes down to predicting [or better: measuring] the polar fields. I use the observations since 1976 from WSO supplemented by the latest data from HMI to determine the solar axial Dipole Moment [DM] comparing it to DM at the previous minimum. Already at this time [≈2 years before minimum] the DM now is larger than the previous DM signaling that solar cycle 25 will be larger than cycle 24. 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 lasp.colorado.edu/media/projects/SORCE/meetings/2018/Oral_Presentations/6_c_Svalgaard_Contri.pdf |
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Post by duwayne on May 16, 2022 3:55:03 GMT
Continuing.....
Per the science summarized in my post above, Svalgaard argues that the maximum smoothed sunspot number for a given Solar Cycle is driven by the Polar field strength when it was at its maximum some 5-7 years
earlier. That Polar field maximum of the old cycle occurs when the Sunspots are nearing their minimum at the beginning of a new Solar Cycle.
To measure the Polar field strength Svalgaard uses the Wilcox Observatory Solar dipole measurements. The dipole is the difference between the South pole and North pole readings. One pole is positive and the other is negative. The Dipole Moment or strength of the Polar field is the sum of the absolute numbers. You can find the numbers here.
The Dipole Moment for a given date is equal to 2 times the value on the far right on the table. The number from the far right column is the average (absolute) for the North and South Pole.
To estimate the maximum sunspot number for Cycle 25 Svalgaard uses the average dipole moment values for the 2 - 3 years prior to the beginning of Cycle 25.
Below is a link to a presentation on Dr. Svalgaard’s website. Chart Number 27 is his chart which shows the relationship for cycles 21 through 24 between the maximum sunspot number and the Dipole Moments maximum which led into the cycles.  This chart also shows his prediction for Cycle 25.
(I'd post the Chart here, but I don't like to do so without his permission.)
Note that Svalgaard shows the results using both a 2-year and 3-year average of Dipole Moments and it doesn’t make a significant difference.
From this chart he predicts Cycle 25 to have a maximum smoothed sunspot number of 128 plus or minus 10.
More to follow.....
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Post by code on May 18, 2022 22:04:05 GMT
Leif is in the house!
leif registered for a new account on this forum!
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leif
New Member
Posts: 1
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Post by leif on May 18, 2022 22:22:09 GMT
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Post by ratty on May 19, 2022 4:12:10 GMT
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Post by code on May 19, 2022 15:49:18 GMT
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Post by duwayne on May 19, 2022 16:32:59 GMT
Leif, Thanks for the post. And congratulations on the Cycle 24 prediction.
Do you see anything coming along which would allow longer term predictions? Any views on Cycle 26?
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Post by blustnmtn on May 21, 2022 1:40:27 GMT
If there is anything we could benefit from here at solarcycle25, it is the occasional chastising from an actual solar scientist 😎 Welcome Leif!
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Post by missouriboy on May 21, 2022 2:39:26 GMT
If there is anything we could benefit from here at solarcycle25, it is the occasional chastising from an actual solar scientist 😎 Welcome Leif! Hear here. |
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Post by gridley on May 21, 2022 11:38:43 GMT
If there is anything we could benefit from here at solarcycle25, it is the occasional chastising from an actual solar scientist 😎 Welcome Leif! Hear here. I just hope he's not a Leif on the wind. :-} |
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Post by acidohm on May 21, 2022 22:17:53 GMT
I just hope he's not a Leif on the wind. :-} Leif is an old school solar24 poster, and very helpful responder to questions in the past to boot! |
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Post by gridley on May 22, 2022 11:38:00 GMT
I just hope he's not a Leif on the wind. :-} Leif is an old school solar24 poster, and very helpful responder to questions in the past to boot! I intended a pun; I meant no disrespect. |
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Post by ratty on May 22, 2022 11:59:15 GMT
Leif is an old school solar24 poster, and very helpful responder to questions in the past to boot! I intended a pun; I meant no disrespect.We know you didn't .... |
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