Solar cycle progress to maximum

Posted: February 24, 2012 by tchannon in Astrophysics, Solar physics, solar system dynamics


The solar polar magnetic field goes through zero at about sunspot cycle maximum, with the magnetic cycle running at half the speed, one reason why alternate sunspot cycles are similar.

The present solar situation is genuinely anomalous with no-one clear on what is going to happen next.


This is a local copy as of posting date of Dr Hathaway’s version of the butterfly diagram (click for full size). The excellent web page with links to data and current diagram is here

Wilcox data and plots here, more general page here with other metrics.

SIDC data etc. is here

I chose the easy way to align SSN and the magnetic data for plotting. Daily SSN is low pass filtered at about 25 days, then decimated to identical points as the magnetic data, 10 days. This is accurate enough. End compensation is used.

If anyone wants the data used, ask, can do an xls.

[edit: WSO polar data imported to XLS polar-2012-2 (315k, version ’97-2007)]

Regulars at Tallbloke’s have been suffering withdrawal symptoms, so there is a solar post, nothing special but a start as a return to normal business.

Post by Tim Channon, co-moderator.

(cross posted to my own blog)

  1. Hans says:

    Please Tim,

    Show the graph below in this thread. Your polar magnetic graph seems to be an average of this one.

    includes an obvious yearly component and it is “explained” by earth orbital situation in relation to the solar equator if I have understood the text correctly. I doubt that this is the full explanation for several reasons. This might be a very interesting topic to discuss.

    What is the longest time series you can find of solar mgnetic field if you go down to monthly averages and where can be it found?

  2. tallbloke says:

    Leif Svalgaard is an expert on the variations in the solar polar fields and what causes the annual term. Google on WUWT for lots of detailed explanation.

  3. Hans says:

    Rog and all,
    Couldn´t find anything about the yearly variations googling Leif Svalgaard and WUWT but found the information that Polar field strength is measured independantly at both poles. See
    The graphs for each both south and north solar polar field are found there. These graphs relating on daily data are probably a gold mine using advanced signal processing technique to extract information. I am still looking for any “explanation” how “orbital geometri” can produce these varying signals and want to checked it up. Anybody who has a link to how these yearly signals are explained?

  4. tallbloke says:

    Hmm, well, a quick count on the blue curve reveals 26 peaks in 24 years.

    Seems to me you’d expect an annual term due to obliquity, plus maybe an obvious anomaly around the time of solar max.

    There’s a number of polar fields related papers on Leif’s research page here:

    Including this graph from 1966-date

    It looks like there was a hiccup around 1970 too. Around the middle of a low cycle

  5. Hans says:

    This is getting better and better. The signal is not annual according to a Ukranian scientist.
    Still want an explanation why there is a distorted quasi annual signal in solar polar field.

  6. Michele says:

    I think,
    May the next acceleration.

    Step EM activities Southern Hemisphere
    or re-acceleration Northern Hemisphere?

  7. tchannon says:

    I didn’t for various reasons Hans, essentially the data is a mess. (official plots are available on the links given)

    Last time I put up mentioning the data I made a serious mistake and issued a corrected post.

    I am very familiar with the annual term, which is caused by improper data sampling resulting in amplitude modulation of the signal. The field of view varies because the telescope uses a fixed mask and the earth bobs up and down on the solar z axis during a year. (be the same thing as you describe)

    A while ago I did spend some time on synchronous demodulation of the signal but it turns out there is a non-linear detector characteristic which I failed to find a way to fix.

    Fortunately almost all of the problem cancels on average.

  8. adolfogiurfa says:

    This makes me remember Vukcevic´s extrapolation, where we can see maximum at 2012:

  9. tchannon says:

    From December last year on this site

    This is overwhelming evidence it is modulation, a doublet and absence of the known fundamental of 1 year.

    (I think Vuk put up the spectra for the other phase)

  10. adolfogiurfa says:

    Time to revisit, Landscheidt´s New Little Ice Age Instead of Global Warming?

    Without exception, the outstanding negative extrema coincide with periods of exceptionally weak solar activity and vice versa. So there are good reasons to expect that the coming Gleissberg minimum around 2030 will be a deep one.

  11. tallbloke says:

    Using the formula T1*T2/(T2+T1) with Tim’s values of 0.96 and 1.05 we get a result of 0.501. Which is fairly close to half a year. 🙂

  12. Vuk says:

    I don’t think there is any mystery, both solar magnetic field (sun rotates too) and the Earth axes have inclination to the solar equatorial plane, each producing own modulation signal. Modulation for both N & S polar fields are absolutely identical but out of phase by 6 months. Difference of 2×18 (=36) days is due to polar rotation of ~ 30 days and delay or advance the earth moves along its orbit during one solar rotation of 30 days away or towards its inclination extremities.
    If someone is keen to do precise calculations I am confident result would show as in the above.

  13. Hans says:

    Tim and VUK. Many thanks. I tried to get the raw data for the independantly measured solar south and north polar magnetic field. As far as I can understand I only found the sum of them. Where is the raw data that you used where these data series are still separated? Your spectra are very interesting.

  14. Joachim Seifert says:

    Values go up – values go down ….. the solar specialist Judith Lean maintains that
    global temps do not continue as plateau but BY 2014 will be 0.14 C higher than 2010
    and she has the great insights what happens with the Sun and the CO2 which produce
    this temp increase……

  15. Edim says:

    Very interesting cycle, the 24th! It looks like it will have a prolonged plateau extending to 2014/15 with short periods of very low numbers for a cycle maximum. The minimum should be around 2021/22 if it’s going to be a very long cycle. I expect cooling and I think it already started.

  16. tchannon says:

    Hans, there are links in the article. However, there is no data file, you have to copy text from screen, which is awkward.

    Also, there are no column headers. Whole thing is a pain.

    I am just about to upload an xls containing the imported data, with headings. Relatively large (315k), no other data format is accepted by WordPress. Look at the end of the article.

  17. adolfogiurfa says:

    coupling between Jupiter and the Sun, it does not tell anything … model, the current solar cycle will be at its maximum by the end of 2012.

  18. tchannon says:


    This seems to be the phase of the modulation. Extracted the components using bandpass, XY plot.

    This says in phase, essentially no lead/lag. (visual plot confirms)

  19. Tenuc says:

    Good paper from Bart Leplae here about solar barycentre speed changes, along with a ‘prediction’ about SC24…

    Variations of the Sun Velocity correlate in various ways with the Solar Cycles

    The Sun will reach minimum velocity and will start to accelerate as of the beginning of 2012.

    According to the described correlations:
    – The Polar Magnetic fields will reverse
    – The current solar sunspot cycle will stop to increase
    – The solar sunspot cycle will exhibit a ‘flat top’ prior to decreasing

    Interestingly, Leif S thinks we are at solar max…

  20. Vuk says:

    Hi Tim
    Since there is no phase difference between two components then the rotation period at pole must be around 35 days, and imbalance between 2 components (for either pole) is most likely due to the fact that WSO is at 37N rather than at the Equator.

  21. tchannon says:

    Something like that. I was expecting a phase difference.

    Since then something so strange has appeared I’m at a loss on what to think. Probably drop it for the time being.

  22. Tenuc says:

    tchannon says:
    February 24, 2012 at 9:51 pm
    “…Since then something so strange has appeared I’m at a loss on what to think. Probably drop it for the time being…

    Don’t know what you’ve found Tim, but I think we have only seen a tiny fraction of the possible behaviour of our ancient sun. The standard ‘dynamo’ model is full of holes, over which solar physics has had to hastily patch. I expect the suns current anomalous solar behaviour will require several more!

  23. Vuk says:

    Tim according to formula
    solar diff rotation at the poles is 10.53 degrees per day or period = 34.66 days.
    My spectrum shows difference of 34.9 days, error of less than 1%, I think as close as you are going to get.
    Since sun rotates faster than the earth than we have a Doppler type effect, polar field magnetic axis (7degrees inclination to the sun’s equatorial plane) moving towards the Earth’s line of sight for 2/4 of the time (with higher frequency = 347.8 days period) and 2/4 of the time away from the Earth’s line of sight (with lower frequency = 382.7 days) with average of precisely 365.25 days.
    I think I’ll leave it that, unless someone knows better.

  24. tallbloke says:

    polar field magnetic axis (7degrees inclination to the sun’s equatorial plane

    Hi Vuk. I didn’t know that. And the Sun’s equatorial plane is inclined at ~7 degrees to the plane of invariance (average plane of the planets). So does that mean the magnetic axis is at 90 degrees to the plane of invariance? Or some angle between that and 76 degrees?

  25. Vuk says:

    Hi tb
    I was quoting from memory, never good thing to do at 11pm.
    (‘sun’s equatorial plane’ is wrong , should be ecliptic or whatever)

    Svalgaard: Judging from the inclination of polar plumes it seems likely that the magnetic field lines at high latitudes are inclined toward the equator.

    Click to access The%20Strength%20of%20the%20Sun’s%20Polar%20Fields.pdf

    page 234.
    I am sure there must be some more information elsewhere.
    another quote:The solar magnetic dipole is tilted with respect to the Sun’s rotation axis;

  26. Hans says:

    This post deals with the spectra given by Tim (February 24, 2012 at 12:54 pm) and by Vuc (February 24, 2012 at 2:34 pm). I am not sure how they got their raw data but their spectra seem to yield the same information if I have understood the problem correctly. The basic data is shown in the graph at February 24, 2012 at 10:01 am (Hans). It would be nice to know exactly what curve Tim and Vuc have used for their analysis.

    My interest is to related to the quasi yearly signal that can be seen at my graph above (one in blue and one in red). These yearly components at solar north and south pole are 180 degree out of phase most of the time. The existence of these signals is told to be caused by the geometry of the orbit of earth and the equatorial plane of sun because if viewing angles. I directly questioned such a statement when seeing the curves shown in my first comment on this thread. After further investigation I claim that such a conclusion is wrong. The implication of the existence of the quasi yearly component in the Solar Polar Field Strength is that the Earth/moon system directly causes the deviations shown regardless if we understand how this can happen. Observational evidence, if correct, cannot be questioned. Some checking might still be needed but the facts are impressive in this case.

    The reasons for my claim are based on the following facts:
    – An influence that has to do with celestial geometry has to be equal at equal times during an earth year. The yearly solar polar magnetic component (at both poles) are phase shifted by 0.5 years repeatedly (every solar cycle).
    – The spectra produced by Tim and Vuc are very similar and their form is spectacular with a close to zero component exactly at the period 1.00 year. There is no reason their spectra would be artifacts and they both show the same spectral characteristics.
    – Tim´s spectra shows an influence of a “beat frequency” with period T that can be calculated as 1/T = 1/0.96 – 1/1.05 or T = 11.2 (years). Vuc´s spectra will give a “beat period” of 10.44 years calculated in the same way. Both are close to the solar cycle length.
    – The Northern and Southern Polar Field Strength on sun is measured independently. Bot curves can be found at (scroll down). Both curves are phase shifted 0.5 year in each solar cycle and then phase shifted back again in the next solar cycle. This is the reason why Tim and Vuc get the double maxima in their spectra.
    I will send a graph showing the phase shifts in a clear way to Tim and he can incorporate it into this comment. To me it is quite unbelievable that this phase shift seems to have gone unnoticed by professional scientist. I should say that this seems to be the case. I have no earlier information at all about the phenomenon of a quasi one year spectral component in the solar polar magnetic fields and fail to know the history of its discovery and the interpretations of the observational evidence shown at

    Hans Jelbring

  27. Vuk says:

    Hi Hans
    I used data from here:
    In this graph I produced for ‘other purpose’, the SSN peak is at 10.58 years

  28. Hans says:

    Vuk says:
    February 25, 2012 at 10:28 am
    “I used data from here:

    It tells on the WSO site:
    “Each 10 days the usable daily polar field measurements in a centered 30-day window are averaged. A 20nhz low pass filtered values eliminate yearly geometric projection effects.”

    Did you run your spectra calculations on 10 day averaged values and did you chose the low pass filtered values mentioned above or not? Have you used daily (WSO or others) data or/and know if daily values are public?

  29. Vuk says:

    I used first two columns (marked as N and S), the rest I usually ignore.
    Daily values are not always available, sometime noisy so averaging reduces noise, filters were changed in summer 2006, the effect of the noise reduction is evident:

    Has anything changed in the measuring techniques in view of the sudden change of volatility in March 2006?
    Yes and no. The technique has not changed [that is the strength of WSO], but we have a filter that only allows green light to pass. This is necessary as the spectra of different orders from the diffraction grating overlaps [we use the 5th order]. This filter was degrading and less and less light was getting through. As the noise depends on the number of photons entering the photo tubes, the failing filter increased the noise [hence the larger swings] until the filter failed completely and had to be replaced in the summer of 2006. After that the noise essentially went away as you can see here:

    In addition, the noise is always a bit larger during the winter when the sun is lower [fewer photons] and the air mass larger [more seeing problems and scattered light which diminishes the measured polar fields, see….%20at%20WSO.pdf ] . In the late summer of 2008 there were some 8000 wild fires in Northern California (marked by ‘WF’) when the smoke-filled air for several months increased scattered light.
    Furthermore, during the reversal back to 2000 the solar variations were just larger. This is coupled with some calibration problems as stated on the WSO website: “WSO sensitivity problems from CR 1970 – CR 1992 (November 2000 – July 2002) have been quantified and the data have been recalibrated.”
    However to my knowledge the recalibration was only done to the magnetograms and not done to the published polar field data. You can see the problem here [taken from ]

    [ Bad URL, did you mean this one? –Tim]

  30. AJB says:

    Latest plots using WSO filtered N-S values.

    Polar Fields:


    Composite uses daily values smoothed with 30-day and 365-day centred running means re-sampled at 10-day intervals to match WSO polar field resolution. Sources are SIDC, Penticton and Moscow. Planetary event dates calculated using PJ Nauter’s AA+ library.

  31. adolfogiurfa says:

    @Tallbloke: It looks like there was a hiccup around 1970 too. Around the middle of a low cycle
    Which would explain the 1970´s cooling…

  32. adolfogiurfa says:

    Hope there would appear here a cardiologist to tell us what happens with our Sun, it looks like dying !!

  33. Vuk says:

    Data in in the first 3 columns are fixed in time, but filtered columns (the 3 end ones) are moving averages so the last half a dozen entries do change as time progresses!
    As appeared in December’s entry
    2011:11:14_21h:07m:13s……-31Avg 20nhz filt: -22Nf 34Sf -28Avgf
    2011:11:24_21h:07m:13s……-27Avg 20nhz filt: -23Nf 33Sf -28Avgf
    as appears in the latest list
    2011:11:14_21h:07m:13s……-31Avg 20nhz filt: -17Nf 39Sf -28Avgf
    2011:11:24_21h:07m:13s……-27Avg 20nhz filt: -17Nf 39Sf -28Avgf
    So I normally ignore the 3 end columns

  34. adolfogiurfa says:

    These changes are important, as Landscheidt said:

    The IPCC’s judgement that the solar factor is negligible is based on satellite observations available since 1978 which show that the Sun’s total irradiance, though not being constant, changes only by about 0.1 percent during the course of the 11-year sunspot cycle. This argument, however, does not take into account that the Sun’s eruptional activity (energetic flares, coronal mass ejections, eruptive prominences), heavily affecting the solar wind, as well as softer solar wind contributions by coronal holes have a much stronger effect than total irradiance
    Which take us to Vukcevic known curve:

  35. AJB says:

    @Vuk February 25, 2012 at 5:51 pm

    True and I seemed to seen changes with a wider scope than that at one point so I now replace the entire data set at each update. Despite what it says at the top, it’s not obvious how these filtered values are computed. The centred running means for SSN, F10.7 and neutron counts on my composite plot are truncated in the normal manner.

  36. tchannon says:

    I ought to respond with more, running out of time. Seems either I can work on data etc. or try and manage the blog, including doing work for new posts. Suggests I can’t participate as much as I would like.

    In this case I have outstanding mystery results which need much more time. Hans is right something doesn’t make complete sense. Last time I put it down to poor data.

  37. Hans says:

    Vuk says:
    February 25, 2012 at 1:18 pm

    Now I have had time to read the link to the article by Leif Svalgaard. What strucks me is that Leif´s
    graphs of solar polar magnetic fields during four solar cycles seem to keep the yearly component at the same phase. The graph in your comment shows the same. My graph above shows repeated phase shifts. I am also aware that there has been some “fight” about a semi year component in academia.

    I am now informed of the difficulties involved when measuring these values but still these descrepancies seem very odd. What do you say about it all seen from a perspective of investigating the spectral components?

    The daily mesurements that are public at WSO are very interesting to me although there are quite a lot of missing values.

  38. Hans says:

    tallbloke says:
    February 25, 2012 at 12:14 pm

    “We hypothesise that Saturn and Jupiter provide the background drumbeat which governs the solar cycle. The modulation of that beat by the other heavy gas giant planets and magnetically active inner planets is the subject of further investigation which has been taking place on this blog and others. We are getting closer to solving the puzzle and being able to predict the future evolution of solar activity levels with a high degree of confidence. That will revolutionise climate science, because once we can confidently predict solar activity, climatologists will ‘rediscover’ the Sun as an important climate driver. Watch this space.”

    Agree about Jupiter and Saturn running the big solar cycle but it is modulated by actions from almost any other planet and especially the earth-moon system. Energy transfer between elestial bodies is very poorly understood.
    There is no way understanding the causes of earthly climate change without understanding how and why sunspot activity is created. In a way solar activity is “weather on Sun” and long term solar activity variations are solar climate change. However, a number of physical processes are different in creating climate on sun and climate on earth. Some are identical and these are the ones to discover and to understand. Solar activity is NOT created from inside sun as mainstream scientists believe, which first was dicovered by the Swedish oceanographer Otto Pettersson, also the head of Stockholm university at an early part of the 20:th century.

  39. Hans says:

    tchannon says:
    February 28, 2012 at 2:14 am

    “In this case I have outstanding mystery results which need much more time. Hans is right something doesn’t make complete sense. Last time I put it down to poor data.”

    That sounds interesting. Just take your time. If one could get hold of daily northern and southern solar polar magnetic field data it would be perfect. 30 day averaging has already destroyed lots of important information. Monthly variations are of great interest, too, and they have been effectively filtered away as far as I can understand.

  40. Bart Leplae says:

    As per the sunpot index published on:

    The number of sunspots was at a maximum in Nov 2011 (97) and then decreased in the subsequent months (73, 58, 33 in Feb 2011)

    As per my paper:
    Variations of the Sun Velocity correlate in various ways with the Solar Cycles

    Rght at the moment when the Sun had reached minimum velocity, the expected increase in number of sunspots was disrupted. The correlations in the paper show that this effect is similar to what happened in 1802 (when the Sun had just reached maximum velocity).

    My assumption is that the electric currents in the Sun are driven through ‘magnetic induction’ at the moment when the Sun is accelerating/decelating. The acceleration / decelaration determines the direction of the currents and as such the polarity of the resultant Sun magnetic field.

    During the moments when the acceleration/deceleration is weak, the N and S Sun hemispheres tend to show differences in the number of sunspots. When the acceleration is strong, the number of sunspots is more equal. This ‘common acceleration’ could explain why the solar cycles on N and S hemisphere remain coupled.

  41. Bart Leplae says:

    If the electric currents in the sun are induced by the sun of which the velocity changes within a magnetic field, then the question is what this magnetic field is all about.

    The Sun’s corona provides evidence of the existance of such a magnetic field:

    The effect of planetary aberration on Venus transit observations:
    Solar Cycle induced through Coriolis Effectview
    Stellar and Planetary Aberration Working Modelview,%20Leplae

    These papers are based on a model that takes the perspective of a light-carrying medium with increasing angular velocity rotating around the Sun.

    The rotation of this medium is what constitutes magnetism …