Reverse polarity sunspot emerging – Are we past solar cycle 24 maximum?

Posted: November 30, 2012 by tallbloke in Cycles, data, Solar physics

Vukcevic commented yesterday that the polar fields are now both across the zero line.


Submitted on 2012/11/26 at 6:26 pm

An important moment for the SC24, the solar magnetic field has finally changed polarity
a bit later than expected.


Last night reports a new high latitude feature with reversed polarity – an emerging spot.

A bipolar reversed polarities region emerged at a high latitude and was located at N70E03 at midnight. No spots have been observed so far.

Overnight talkshop contributors ‘project722’ and Bill McKintyre reported the spot as definite.


Submitted on 2012/11/30 at 3:08 am

I see a clearly defined but small reversed polarity spot center disk at high latitude. We should start seeing more of these if the polar fields have reversed.

Bill McIntyre

Submitted on 2012/11/30 at 8:52 am

don’t like to barge in here but there is a tiny negative sunspot just under its north pole – – a rare sighting that some people here might like to see (and record as souvenir).

sdo image date 2012-11-30 06:16:12 UT


Is this a signal that solar maximum for cycle 24 has been reached? Time will tell.

  1. What is the basis for the Vukcevic formula? Does the amplitude modulation predict an even lesser sunspot minimum around 2024?

  2. tallbloke says:

    Hi Hans,
    two prominent terms in Vuk’s formula are Jupiter’s orbital period 11.86 years, and the Jupiter – Saturn synodic period of 19.86 years.

    It’s another element in our solar-planetary theory.

  3. Sparks says:

    Is anyone else seeing the third band below the southern hemisphere band?

  4. adolfogiurfa says:

    This is really a Tallbloke´s BREAKING NEWS: Can´t find it anywhere else in the web.

  5. Project722 says:

    adolfogiurfa says:
    November 30, 2012 at 12:56 pm

    This is really a Tallbloke´s BREAKING NEWS: Can´t find it anywhere else in the web.

    Well we are dealing with independent results for the moment. So far, two significant researchers IMO have confirmed using their own formulas and WSO data, that the fields have reversed. I suppose we will have to wait until more reports come in, whether official or independent, before it becomes crystal clear. Visual observations of the disk do seem to suggest something is going on. A reversed polarity region at very high latitude and the flux in the SH seems to be rushing towards its pole.

    Sparks says:
    November 30, 2012 at 12:10 pm

    Is anyone else seeing the third band below the southern hemisphere band?

    Hi Sparks could you elaborate on what you are seeing? What kind of “bands” are you referring to?

  6. janbenestad says:

    notice that we are at an Jupiter-Saturn angle where new sunspot cycles tend to begin (solar minimum). So right now the Jupiter-Saturn cycle is “strong” and we should see some kind of effect on the sunspots (-activity)
    However this SC24 is out of phase with the JuSa cycle, and having solar max here instead of minimum…
    In such cases we normally see the final top in solar activity, sometime next 6-12 months

  7. Sparks says:

    Project722 says:
    November 30, 2012 at 1:51 pm

    There looks like three bands of Faculae, you can see it better in the STEREO Ahead EUVI 195

    It’s a good sign of solar maximum.

  8. Greg Goodman says:

    Looking at the last two full cycles, it seems the little dip we’ve just seen will be followed by steep rise. That may well take things slightly above Vuk’s foruma before it hits the peak.

    The predicitve value of his plot is impressive even to be this close. Mainstream predictions have not been anywhere near that good despite frequent revision.

    Clearly the real data are a little squarer than the idealised harmonics of the formula but even the deviations seem to be consistent.


  9. Edim says:

    IMO, we are not past SC 24 maximum. I stick to ~2013/14, but the exact timing is somewhat arbitrary.

  10. janbenestad says:

    most likely July-Aug 2013.
    Jan-Feb 2014 possible, just as July 2012 also is possible. But most likely July 2013 🙂

  11. mkelly says:

    For those of who are interested but ignorant please point out the spot on the photo. I how no idea which way is north on the sun from the picture.

  12. adolfogiurfa says:

    @mkelly: I don´t see it either, but it would be good to have a better image.

  13. Bart Leplae says:

    The Vukcevic formula resembles the acceleration/decelaration of the Sun in response to the relative positions of the planets. Hereby, the Sun’s velocity is measured relative to the long-term average position of the Sun (not against the barycenter of the solar system).
    A diffference with the Vukcevic formula is that the to-be-expected strength (in 2017-2018) would be close to the strength of previous cycles and would reverse in polarity in 2022.
    The ‘damping effect’ as of 2013 in the Vukcevic formula looks somewhat unnatural …

  14. wayne says:

    I’m like others, could we get an arrow or circle on that pic so when you go to the SDO site you know where to look for it, and, maybe a note on how you can even tell if a spot has reversed or not.

  15. tchannon says:

    Busy so,

    Read about deducing the polarity

    Should be figuable from Wilcox data

  16. adolfogiurfa says:

    Little changes in the VACUUM: The atmospheric pressure of the sun, instead of being 27.47 times greater than the atmospheric pressure of the earth (as expected because of the gravitational pull of the large solar mass), is much smaller: the pressure there varies according to the layers of the atmosphere from one-tenth to one-thousandth of the barometric pressure on the earth;(13) at the base of the reversing layer the pressure is 0.005 of the atmospheric pressure at sea level on the earth;(14) in the sunspots, the pressure drops to one ten-thousandth of the pressure on the earth.

    Click to access cosmos_without_gravitation.pdf

  17. Gerry says:

    Phil Scherrer’s movie of the magnetic development of giant sunspot AR1618 from Nov 15 through Nov 22 shows how dynamic and complex the magnetic changes of one small region can be in a single week.

    The movie was made using SDO Helioseismic and Magnetic Imager(HMI) data. White regions are positive polarity, black regions negative:

    In places with mixed polarities, such as the solar corona, magnetic fields can reconnect and erupt, producing solar flares:

  18. AJB says:

    IMHO Vukcevic has jumped the gun. He appears to just be plotting the WSO unfiltered average and not accounting for the geometric projection effect. The last published WSO data point is for Nov 8th 2012. The South Pole is tipped away from us to the maximum extent around Sept 9th. Therefore on Nov 8th the Sun was still about a third of the way from being upright again, giving readings that are not centred over the poles. That is why the 20nHz low-pass filter is necessary. The Sun will be square-on to us again around the Dec 10th. Allowing for noise you can then gauge roughly where we’re at from the unfiltered values. WSO’s and Leif’s plots show the projection effect pretty well:

    IIRC Leif likes to see one rotation with switched values at both poles before he deems the switch to be complete. I presume he has other means of corroborating that.

    Anyhow, here’s my current guess based on trends through the Sun upright readings, allowing for noise and what may or may not be gas giant influences (further tests of that will arrive on Nov 5th 2015, July 11th 2017 and Nov 2nd 2020). Anything shown beyond the current data is pure guesswork:

    (here is old version “”)

    Hopefully it’s at least fairly self-consistent. If anyone spots any obvious anomalies, please let me know. It looks as though the South Pole will switch just before the New Year. With noise, that could easily appear to be a month or so later as the unfiltered values skirt along the axis for a while. We’ll need to wait another 18 months to see what the firmed up filtered values look like. You might think I’ve been a bit vicious with damping after the switch. Perhaps, but I think the run up to 2017 or so may have one or two surprises in store. Anybody’s guess really, only time will tell.

  19. tchannon says:

    AJB, can I pull that large plot onto WP servers and show directly please?

  20. AJB says:

    Tim, sure. No problem.

    [thanks, ever want it removed, ask –Tim]

  21. AJB says:

    Tim, could you replace that with this one:
    I plotted the first two gas giant events in the wrong year (wondered why the inflection centring looked off too!). New one is labelled Revision 1. Makes no difference to the estimate.

    Many thanks.


  22. vukcevic says:

    The backdated near time filtered values alter continuously as you go along . I had prolong discussion about this with Dr.S. His suggestion is to use direct values, then by subtracting S from N the annual tilt and great deal of noise due to the atmosphere and instrumentation is automatically eliminated.

    You can check this if you compare filtered recorded for date at the start of 2012 and those shown currently for the same date
    Recorded at the time:
    2012:01:03_21h:07m:13s -7N 50S -29 Avg -22 Nf 35 Sf -28 Avgf
    current file shows:
    2012:01:03_21h:07m:13s -7N 50S -29Avg -9Nf 42Sf -26Avgf

  23. tchannon says:

    It’s about now either way, readers can see two points of view.

    Adding a third.

    Some time ago I looked in detail at the WSO data in detail.

    What I found was the fixed telescope field of view combine with the varying angle of view has the effect of a modulator. The resultant annual signal does not have a period of one year but is the modulation products split either side of one year. A spectrogram is in this blog comment from a year ago, and the article there shows the state of the data then

    Since two measurements are made from the same earth location the error should cancel and to a large extent it does, hence the simple sum is almost free of corruption.

    However, when I tried demodulation of the separate signals I found there is more going on as well as inconsistency of the measurement system over the time of the dataset, so this is not practical.
    I suspect the optical to magnetic law is non-linear but I couldn’t figure this out, is needed to untangle the lot.

  24. vukcevic says:

    I agree.
    This is not an exact science.

  25. AJB says:


    Of course, the filter is recursive and the last 6 months or so is pretty meaningless. But this has nothing to do with the filter. You have just said you are plotting N-S (WSO unfiltered average x 2). That’s not a measure of what south alone is doing. All it gives you is when the average crossed the axis. The switch won’t be complete until south has crossed over too and that needs interpolation taking account of the projection effect to predict. Take another look at Leif’s plots, particularly the one on the left.

    All I’ve done is the same thing except I’m using the square-on view times as a guide and trying to take account of that huge inflection on 23/02/11 (howsoever caused). I may well have undercooked it. Note that Leif’s interpolation doesn’t have south going over until late April. The unfiltered south values look like they’re now going to skate along the axis for a while. For how long and whether they draw back again are the big questions. Only time will tell.

  26. adolfogiurfa says:

    @Vukcevic: This is not an exact science…Anyway it is enough precise to show that we live in “interesting times” to say the least.
    A question:Does a decrease in the Sun´s electromagnetic field sets the earth’s electromagnetic field more prone to changes?

  27. vukcevic says:

    As I said it’s not exact science.

    From WUWT

    vukcevic says:
    June 23, 2009 at 2:02 pm
    A 20nhz low pass filtered values eliminate yearly geometric projection effects. My choice is clear: filtered data.

    Leif Svalgaard says:
    June 23, 2009 at 3:44 pm
    Which also shows the undesirable side effect of introducing spurious end-effects. As the two values approach each other the filtered data diverges. Sometimes it pays to listen to reason.
    The curve at the bottom is the difference N-S. It shows no strong divergence recently, if anything a slight decrease [as we would expect since cycle 24 has already begun to eat away at the polar fields].
    cherry picking is what I call it.

    I shall leave it at that.

  28. AJB says:

    Not an exact science? Well sure, at face value. But the accuracy of centring of gas giant events on those filtered mag cycle inflections is stunning (all 21 of them). Maybe you guys should look a little closer if you’re looking for planetary influences. Coincidence? More than likely but let’s just see what 2015 and 2017 bring to the party.


  29. AJB says:


    Again, this has nothing whatsoever to do with the filter or filtered value end-effects. Interpolation is done on the unfiltered values (plus firmed up filtered values only in my case). We really had better leave it at that.

  30. adolfogiurfa says:

    Well, well, when is it going to be the next solar maximum? 🙂

  31. tchannon says:

    Try reading what Hathaway the butterfly keeper has to say.

    For example “In addition to Hale’s Polarity Laws for sunspots, it was found that the Sun’s polar fields reverse as well. Babcock (1959) noted that the polar fields reversed at about the time of sunspot cycle maximum. The Sun’s south polar field reversed in mid-1957 while its north polar field reversed in late-1958. The maximum for cycle 19 occurred in late-1957. The polar fields are thus out of phase with the sunspot cycle – polar fields are at their peak near sunspot minimum. This is also indicated by the presence of polar faculae – small bright round patches seen in the polar regions in white light observations of the Sun – whose number also peak at about the time of sunspot minimum (Sheeley Jr, 1991).”

    From an open access journal pdf (65 pages) which is linked from his solar cycle page

  32. adolfogiurfa says:

    According to Vukcevic´s formula and graph has crossed the 0 nT axis, so we are about the maximum, so within days or weeks we will be witnessing a sudden maximum.

    [Reply] Behave! 🙂

  33. adolfogiurfa says:

    Sun´s behavior according to Dr.Svaalgard :

  34. AJB says:

    Still not there but getting closer maybe …

  35. AJB says:

    But then again …

  36. J Martin says:

    @ AJB. Interesting that on the graph,
    S-N opposition coincided slap bang at solar max, just a coincidence ?

    Though it does of course make one wonder where S-N conjunction occurs, presumably too much to hope for that that would tie up as neatly at solar min. Some way to the right of the graph.

  37. J Martin says:

    And now looking at the WSO graph again I seem to have got max and min mixed up, though, for that matter, what are we looking at ? Sunspots locations rather than sunspot numbers ?

    If so then there seem to be a couple of years between the two.

    Perhaps you can elucidate ?

  38. AJB says:

    Oops-a-daisy, all of a quandary again …

    Pole Switch
    North Minus South

  39. tallbloke says:

    AJB: Whoah! Freaky! Sun surprise monopole wierdness…

  40. p.g.sharrow says:

    AJB says:
    February 1, 2014 at 10:29 pm: pole switch:

    This looks strange. Is GOD double clutching the shift, or maybe double shifting? pg

  41. AJB says:

    The bigger picture:

    Only a few years to wait till the paint dries.