Solar Science

A blog of solar physics

Ken Tapping: Still no sign of the next cycle

with 16 comments

Previously on this blog, I’d mentioned my skepticism that one decent sunspot marked the end of the hiatus in the solar cycle we’ve seen for nearly two years. It might be my nature, but everybody has been wrong before.

As part of my public duty to actually ask real scientists monitoring the Sun, I wrote to Dr Ken Tapping of Canada’s National Research Council at the Herzberg Institute of Astrophysics in British Columbia:

Dear Dr Tapping

For the first time in a very long time, the Sun has managed to produce a sunspot (1024) which has lasted more than a few hours.

Is there any sign of an upswing in radio emissions indicating an end to the hiatus?

Best regards

John

and Dr Tapping replied (with my emphasis):

Hi John,

Last weekend I saw a really nice sunspot group on the Sun, which could have been part of the new cycle. The solar radio flux went up a little while it was there. However now the flux has slumped back to low values again.

Some theorists have suggested the new cycle is currently under way, but that for some unknown reason we are not getting the spots to go with it. I’m not sure what that really means, so I am making no suggestion as to what is going on.

Being very conservative, according to the measurements being made under our Solar Radio Monitoring Programme, we have yet to see signs the next cycle is really under way.

Regards,

Ken

Now this is what I’d thought, that the nice sunspot (1024) we’d seen did not presage a change in the behavior of the Sun: the solar wind speed remained subdued, coronal holes remained very small, there were no prominences to speak of.

It also baffles me how “some theorists have suggested the new cycle is currently under way, but that for some unknown reason we are not getting the spots to go with it”. If there are very few sunspots and the radio flux remains extremely subdued, on what basis are these theorists making their statements?

It could be that this is the first “radio quiet” solar cycle … anyone believe that?

So for solar physicists, it remains “interesting times” and probably a time to clear out some old theories and start again.

My thanks to Dr Tapping for the correspondence.

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Written by John A

July 10, 2009 at 8:53 am

16 Responses

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  1. Interesting comments by Dr. Tapping. Good question you asked as well. If no more Solar Cycle 23 sunspots are emerging and the sun is not ‘firing up’ to indicate that cycle 24 has begun then are we still in solar minimum? The 1st cycle 24 sunspot was seen in January, 2008 – 18 months ago. Still the sun activity remains at very low levels. I wonder how long this will continue. Best approach would be to watch and learn as the learning curve should be pretty steep. Very interesting indeed.

    Dave.

    July 11, 2009 at 1:49 pm

  2. Re #1

    Good question. Nobody knows what the cause is. NASA clearly doesn’t (although it likes to pretend it does).

    I actually recall the first person to record an SC24 spot was in 2006, although it was disputable as the latitude was very low and its difficult to pick the polarity of low latitude spots.

    The only reason I wrote to Dr Tapping was that I wasn’t getting any vibes that anything fundamental had changed in the Sun – the solar wind was low, prominences were tiny, the magnetic field very subdued. So other than the one persistent spot (and I was glad to see it persist), was there anything to say that SC24 was going to behave itself?

    Dr Tapping (a courteous and timely correspondent) replied to a straightforward inquiry with a simple reply.

    These are interesting times in solar science.

    John A

    July 11, 2009 at 6:15 pm

  3. Well, an explanation for no significant upswing in F10.7 would be that the signal is only just at the level of the background noise. The peaks break through this, but the true minimum level of ‘no spot’ flux has been hidden. The observation from this effect would be a compression of the curve at it’s lowest point. We know that this minimum has given more time for sc23 to fade away before sc24 becomes visible – my guess is that we have had a chance to observe much more of the ‘tail ends’ than would be typical, and a plot of (a^2+b^2)^0.5 for 2007.0-2008.12 added to 2008.12-today would produce a more regular looking shape for the minimum – together with a better reflection of if today would be expected to appear as an upswing or not. I suspect that with more overlap between cycles, the old cycle would still be dropping away at this stage (whereas now, sc23 really is below the noise level)

    Sean Houlihane

    July 11, 2009 at 9:33 pm

  4. […] to this blog there are no signs of a new cycle although there has recently been a sunspot which all seem to […]

  5. Sean Houlihane

    July 12, 2009 at 12:13 am

  6. Sean:

    Welcome to my blog.

    an explanation for no significant upswing in F10.7 would be that the signal is only just at the level of the background noise. The peaks break through this, but the true minimum level of ‘no spot’ flux has been hidden. The observation from this effect would be a compression of the curve at it’s lowest point.

    My question: is there any difference between this and no upswing at all?

    John A

    July 12, 2009 at 11:56 pm

  7. In my mind, yes,there is a difference – provided that the increase continues. Excepting the dip at Oct 07, the flux was dropping at a steady rate below the background level from Dec07 to Dec08. Since then, there has been a steady increase at about the same rate – such that the new cycle is adding almost half as much power as the constant background level. if it keeps up at the same steady rate of increase, by the end of the year, the flux will be 75, and 12 months from now it will be 83 (at the quiet times between spots).
    Cycle 24 seems to have started to ramp up 18 months late if compared with cycle 23, but it is now at the point where the ramp is becoming visible. for the last minimum, the new cycle came into view whilst the old cycle was still decaying, hence the more pronounced upturn. Need a couple of months more data though 🙂

    Sean Houlihane

    July 13, 2009 at 1:22 am

  8. Sean

    I admire someone prepared to stick their neck out like that, especially as the “signal” and “noise” are the same magnitude.

    What would falsify your prediction?

    John A

    July 13, 2009 at 9:03 am

  9. Now you’re asking 🙂 At this stage, I have only looked at one previous cycle, and have made no attempt to correct for the effect of sunspots so I am not really in a position to make much of a guess about the rate of ramp-up. So with the caveat that I may revise rather than discard my model my -1sigma (measurement noise) limits for adjusted F10.7 are:
    July 70.6
    Aug 71.3
    Sep 72.0
    Given what we know about July, any average below 69.0 in the next few months would be a serious blow to my curve fit.

    Sean Houlihane

    July 13, 2009 at 11:50 pm

  10. I’ve enjoyed this site. Here’s a link to a summary by a professor affiliated with Stanford showing trend data, with a clear [though hardly dramatic] increasing trend in a number of measures, suggesting that solar activity is increasing:

    His main data page is: http://www.leif.org/research/

    Regards.

    Ken

    July 14, 2009 at 12:23 am

  11. Ken

    That would be Dr Leif Svalgaard’s site. Other than the distracting quadratic trend he’s drawn through the F10.7 data, there’s no trend to speak of.

    Svalgaard has a habit of attributing trends where there is none. It’s quite annoying.

    John A

    July 14, 2009 at 3:45 pm

  12. John A. – re your last remark (post #11, “…attributing trends where there is none…”) re my reference (post #12) — that’s pretty much what I meant by “…hardly dramatic…”

    I posted that as one possible example of reasons/examples that underly Ken Tapping’s observation made in his note in the blog entry (“Some theorists have suggested…”).

    I’ve perused NOAA’s site (http://www.swpc.noaa.gov/Data/index.html) and compared figures & agree that whatever underlying “trend” is there is pretty faint & subjective — one can see what they want.

    After following the GONG site for some time (http://gong.nso.edu/ — especially the Synoptic map link) it did appear that there’s been a “surge” in activity (which is to say that some spots & near-spots are being observed more often)….but….how sustained that will be is unclear. Recently, things seem to be settling down again.

    What seems pretty clear to me as a “newbie” to this is that analysis of multiple data from multiple sources can result in a much different overall assessment than consistent use of a single set of data/sources, however credible those latter sources & data may be.

    Frankly I’m glad about your comment re Dr. S’pattern — I suspected the same. There’s a number of credentialed researchers out there that seem to have a certain viewpoint they’ve invested some effort in, and which seems to affect how they see/interpret new data as it comes. I can’t say they’re trying to force-fit new facts to fit some preconceived theory of how things are, but, unfortunately, I can’t conclude that’s not what’s happening.

    Again, I’m a “newbie” studying this area, which I find interesting for a vareity of reasons. But I can’t help but notice the degree of speculation interleaved with objectively measured data [in published peer reviewed papers and other reporting] tends to be unusually high compared with other areas of science. Sorting it all out is something….

    Ken

    July 15, 2009 at 10:48 pm

  13. Ken

    I find myself wondering if there is significant autocorrelation (or persistence) in the 10.7 cm radio flux data which would simulate some false trends where there would be nothing there.

    I must learn how to calculate these things.

    John A

    July 19, 2009 at 11:13 am

  14. John, I’m not sure that autocorrelation is the right term, since any real trend will be likely to show autocorrelation – you’d need to identify a mechanism and then factor any persistence into your trend analysis. To get an idea of if a series does exhibit autocorrelation, convolve it with itself (sum Xi*X(i+n) and compare with sum(X^2) for differing offsets. I can’t tell you what noise looks like, other than the correlation drops as n increases. Actually, you probably need to subtract the average first, so the numbers that are summed can also be negative)
    Clearly, one day will be closely related to the next – what I think you are wondering about is the error bars associated with the trend (as in a month of hot weather maybe p/5 as likely as a hot day, not p^30 if p is the chance of a single hot day). One big spot today means nothing for next months spots.
    For what it’s worth, I don’t see the degree of speculation vs hard data is any different in this area than than high energy physics – it’s just that most people are rarely exposed to the guesswork that goes into connecting the starting and ending states.

    Sean Houlihane

    July 20, 2009 at 3:27 am

  15. Sean

    That’s fair enough. The observations will tell whether you’re on the right track or not.

    John A

    July 22, 2009 at 10:24 pm


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