I had written back in July 2008 about the 10.7cm solar radio flux hitting a new record low value. Part of that has to do with the inverse square law and the distance of the earth to the sun, which is at a maximum at the summer solstice. As you can see below there has been a very gradual rise since then as we approached the winter solstice. David Archibald provides an update below and compares our current period to other solar cycles. – Anthony
UPDATE: In comments, Leif Svalgaard offers his graph, and also speaks of the flatlining. See below the “read more” – Anthony
The graph above is of two year windows of the F 10.7 radio flux centered on the last five solar minima. They are stacked up so that they are 20 solar flux units apart on the same vertical scale. The original data is from: http://www.ngdc.noaa.gov/stp/SOLAR/ftpsolarradio.html#qbsa
That site notes:
“The quiet sun level is the flux density which would be observed in the absence of activity. Extrapolation to zero of plots of the 10.7cm flux against other activity indices such as plage area or total photospheric magnetic flux in active regions suggest a quiet sun flux density of about 64 s.f.u. This is rarely attained.” The lowest daily value in this minimum to date was 64.5 in June 2008.
What is evident is that this minimum is quite different from the previous four in that the intra-monthly amplitude has died from June 2008. The monthly average low was July 2008 and the series has been in uptrend at 0.7 units/month thereafter. This is a very weak but very consistent uptrend, perhaps the first sign of a rising Solar Cycle 24. There is very little noise in this signal, suggesting a very weak Solar Cycle 24.
– David Archibald
UPDATE: Leif Svalgaard writes in comments:
As part of my ‘homework’ for the Sunspot Panel [2 years ago] I produced a short document
http://www.leif.org/research/When%20is%20Minimum.pdf
comparing F10.7 and MgII [another solar index] around minima. I have updated the graph in the document to show the flat-lining of F10.7.
Robert Bateman (08:47:28) :
David Archibald (20:49:23) :
Solar Cycle 23 is increasingly looking like Solar Cycle 4. It is a beautiful world.
When making such comparisons, one must actually look at the data first. So a good question is: “what did SC4 look like?” This is not easy to answer, because our data is scant. Here are plots of ALL the data we have: http://www.leif.org/research/Sunspot%20Number%20Data%201775-1802.png
The blue dots and curve show the Group Sunspot Number GSN, the red curve the Wolf Number WN, and the green dots and curve the sunspot data acquired by Staudacher 1749-1796 and recently re-measured by Arlt [ http://www.leif.org/research/Staudacher-1.pdf ]. We don’t really know what the ‘true’ sunspot number was or how to calibrate Staudacher’s data. I have simply scaled his data so that they fit halfway between the GSN and the WN.
The next problem is how to compare cycles of different sizes. The standard solution is to scale them to have the same mean over an interval and to shift them in time until you get a ‘good’ fit. the second panel shows this done for SC4, SC13, and SC23. What makes SC4 so special is that halfway down its decline, it somehow got a resurgence that pushed the minimum out by several years. We don’t know if the ‘new’ flux was old cycle [i.e. 4] or new cycle [i.e. 5] polarity. Most solar researchers would go with old cycle.
Arlt has also produced the butterfly diagram for those cylcles here: http://www.leif.org/research/Staudacher-2.pdf [see page 10] and it looks quite normal for cycle 4 [although cycle 1 looks strange].
For those reasons I argue that the cycle to compare SC23 with is SC13, in spite of the numerological and astrological musings [“ordinal position in its quintet”]. The heliomagnetic field for SC23 also matched closely that of SC13 [page 9 of http://www.leif.org/research/AGU%20Fall%202008%20SH24A-01.pdf note the circles 107 years apart]. The cold data of science can sometimes put a damper on enthusiastic personal opinion and pet theories, like it or not.
Leif Svalgaard (11:21:06):
[…] But to mention a few of the known unknowns:
[…] 3) what is a sunspot? [yes, we don’t know!] […]
Hugo M (12:46:20): I learnt some time ago, looking onto a sunspot would be the equivalent of looking onto a cross section of a MHD flux tube?
Leif Svalgaard (13:55:52): You are substituting one word with another [much more fancy one], but that doesn’t solve anything. How and where does such a tube form? how does it hold together? how deep is it? Is it one tube or a bundle of very many small tubes? etc.
Dr. Svalgaard,
it took me some time to get my hands back on a solar physics textbook written by your German confreres Scheffler and Elsässer, who gave reason to my infidel question. At any rate, it wasn’t just me who substituted one word by another (certainly much more fancy one), but your former colleague Horace W. Babcock, who put sunspots in context with his solar dynamo theory. He, for one had not simply renamed things, but had given a physical explanation which linked a physical effect (sunspots) to a possible cause (magnetic flux tubes), the latter induced in solar plasma by sun’s polar field.
A nice illustration which I took from the above mentioned book is available here:
http://img6.imageshack.us/img6/2157/fluxtubessunpotsqq5.jpg
The caption reads: “Fig. III.53: Formation of a bipolar sunspot group by local buoyancy of a magnetic flux tube located beneath sun’s surface (a) and it’s breakout to the upper solar atmosphere(b). (According to H. W. Babcock)”
The next figure puts the former in context:
http://img23.imageshack.us/img23/7563/babcockpm6.jpg
The caption reads: “Fig. III.54: Conceptions of H.W.Babcock about the genesis of the magnetic cycle of sun’s activity. (According to C. Livingston)
You may be right that the zoo of evolving solar dynamo theories had not solved so much until today. Else it would not be conceivable that the former solar prediction panel seriously tried to decide a scientific question by democratic voting – and finally failed in doing so, fortunately.
Hugo M (21:45:33) :
Your post notwithstanding, we still do not know what a sunspot is. About the only thing that is certain is that it is not the eruption of a fat flux tube as envisioned by Babcock. Some new ideas may be found here: http://www.leif.org/research/Percolation%20and%20the%20Solar%20Dynamo.pdf
Leif Svalgaard (20:44:23) :
Just take what I say at face value, then it is easy. SC23 began in 1994 off the left edge, and SC24 in 2003 or 2004, about where you have the arrows. Sunspots tend to form at the boundary between purple and yellow; where the shear [velocity difference] is the largest. I have tried to explain this several times before. Here is a plot of the velocity from Mt. Wilson: http://www.leif.org/research/Torsional%20Oscillation.pd
Thats not in my nature unfortunately and would rather find out things the hard way even if I end up with egg on my face, and I tend to find things when I dig. The plot you provide is quite different from the Dr. Howe plot, as if a lot of detail might be missing. This new plot shows the effect of differential rotational far more clearly. Have all the sunspots from the past couple of cycles been plotted on the differential rotation diagram at the corresponding latitude and date…that would be something to see.
Geoff Sharp (22:55:52) :
“Just take what I say at face value, then it is easy.”
Thats not in my nature unfortunately
Indeed it is not, which does make it a whole lot harder than it need be.
The plot you provide is quite different from the Dr. Howe plot, as if a lot of detail might be missing. This new plot shows the effect of differential rotational far more clearly. Have all the sunspots from the past couple of cycles been plotted on the differential rotation diagram at the corresponding latitude and date…that would be something to see.
I’m not sure which one you are referring to. Which has something missing? You are a bit muddled with this ‘differential rotation’. The diagrams show something very different. The differential rotation has been removed from the data. What the diagram shows is what is left after the removal: narrow bands that locally rotate slower and faster than the global differential rotation.
Here you can compare the magnetic field [and thus the spots] with the torsional oscillation: http://www.astro.ucla.edu/~obs/torsional.html
Leif Svalgaard (23:11:35) :
The original MWO graph you referred:
http://www.leif.org/research/Torsional%20Oscillation.pdf
looks to be missing detail, but as you have explained we are not comparing apples.
I might keep digging….superimposing the sunspot data over Dr. Howes plot might be interesting.
I will post an article later tonight on my mirror site (Auditblogs is having some major probs). For those interested go to: http://users.beagle.com.au/geoffsharp/
Geoff Sharp (23:43:03) :
The original MWO graph you referred:
http://www.leif.org/research/Torsional%20Oscillation.pdf
looks to be missing detail,
compared to what? To me it has the most detail of all of them.
Re Dr Svalgaard (21:22:52)
WSO? You are not going pre-emptive on my data sources are you? Why not at least wait until the graphic has been posted? You have good reason to be concerned. The graphic looks good with a lot of predictive power, and it is saying August, 2009 for the month of minimum and possibly into 2010. I’ll to the math for everyone. A 13.4 year Solar Cycle 23 means that it will be 3.8 years longer than 22, which at 0.7 degrees per annum means a cooling of 2.7 degrees for places like New Hampshire. The solar cycle length – cooling relationship is 0.002 degrees per day, and every day counts. There is not one Solar Cycle 24 activity that has yet turned upwards.
I may have missed it, but did anyone offer an explanation of Anthony’s question relating to the sudden drop in the ap index in October 2005.
To my uninitiated mind. there are no obvious causes in all this slow-changing dynamo dynamic. It looks as if something delivered a ‘shock’ to the Sun’s system. Are there any electric currents out there sufficient to shock that system?
And in the discussions about solar wind and climate – am I right that the solar wind is also a kind of current with a voltage? And the same for cosmic rays and ‘particles’ all measured in GeVs? The Earth has an electric current circuit, and a huge voltage differential from top of the atmosphere to bottom. Voltages – especially voltage shocks, affect aerosols (When conducting his cloud chamber experiments, Svensmark & co used voltages to clear the chamber after each experiment), and of course lightning has that air-clearing effect.
I draw attention to this partly because no one much talks about it and partly because in some of the atmospheric science I have been reviewing of late, there is strong evidence that ‘global dimming’ (the cooling from 1945-1980) was not caused by human pollution, but by natural changes in aerosol and cloud. The end of ‘dimming’ occurred in the mid-1980s and early 1990s and satellites showed clear-sky increases in shortwave flux to the surface – global ‘brightening’, as well as less cloud cover (4% decline globally from 1983-2000). That SW flux can explain all the late 20th century warming – in terms of watts/square metre it is 4-6 times the greenhouse gas increment over that period.
I would love to see a thread on atmospheric electrics! As well as anything similarly related to the Sun – after all, Hannes Alfven, the ‘father of magneto-hydrodynamics’, had a theory that the photosphere was an electric-arc phenomenon – what happened to that theory?
Sorry if all these questions have been answered!
Leif,
With the proviso that I am not a physicist or a scientist, but only a curious onlooker… Is there any possibility at all that sunspots could be eddies created by the differing speeds of solar rotation?
I am sure this is a very simplistic question, but still wondering.
Thanks,
Mike Bryant
Peter Taylor (10:13:06) :
“Right now there very large areas of the Pacific clear of cloud and absorbing SW in the southern hemisphere most strongly .”
Peter, How do you know this? Have you any ideas as to the why the cloud has disappeared? What sort of cloud? Where exactly?
From DIGITIZATION OF SUNSPOT DRAWINGS BY
STAUDACHER IN 1749–1796
Page 13 graph
Figure 12. Average sunspot area in 183-day averages (top) and 365-day averages (bottom).
The vertical lines are an indication for the error margin in that they are taken from the
square root of the number of individual data points entering the average. The lower panel
also contains the Wolf numbers from the SIDC, Belgium.
The Wolf Numbers from SIDC work for me.
Staudacher’s aren’t bad, either.
The main point is the overall shape of cycle 4 and it’s length as compared to SC23 (still going…and going….and going).
SC13 ended at 12 yrs of age.
SC23 > 12.5 yrs
SC13 was preceeded by a weaker cycle of 11.2 yrs.
SC23 is preceeded by a stronger cycle of 10 yrs.
I used the graphs from Solar Terrestrial Activity Reports
http://www.solen.info/solar/cycl1_20.html
Copyright notice: The graphics can be freely used provided that proper credit is given. The graphs have been prepared by Jan Alvestad based on data from SIDC, Brussels. – which I did.
http://www.robertb.darkhorizons.org/DeepSolarMin.htm
http://www.robertb.darkhorizons.org/DeepSolarMin1.htm
It looks to me like SIDC has done a good job here.
I even took the source you quoted me for the monthly ssn’s for the early cycles and made my own graphs. They agree with Jan Alvestad’s graphs.
I’ll go with SIDC for thier consistency, and I’ll go with David’s comparison
of SC23 with SC4, not because I agree with him, but because I found it independently, and nobody put the idea in my head.
“Do I sense a slightly jealous undertone here or do you really mean what you say?
I personally think we could not do any better.”
I heartily agree with the second sentence. Dr. S. has a big gift as archivist and interpreter of data and is perhaps the most prominent scientific programmer around.
Moreover, I have learned a lot from his corrections.
The former sentence, however, seems the inverse of reality. Keep your day job.
David Archibald (01:55:24) :
WSO? You are not going pre-emptive on my data sources are you? Why not at least wait until the graphic has been posted? You have good reason to be concerned. The graphic looks good with a lot of predictive power
What kind of fluff is this? I was one of the builders of WSO [and I’m back at WSO]. I wrote the program that is used at WSO to calculate the spherical harmonics [that determine the flatness of the HCS]. I know whereof I speak. The ‘graphic’ has no predictive power at all, only the physics behind it. Show us your graphic and explain whence it derives its power.
I have superimposed all the recent sunspots as taken from SIDC over the top of Dr. Howe’s differential rotation diagram using an animated gif. The pattern matching is spot on, clearly showing the relationship.
http://users.beagle.com.au/geoffsharp/comb2.gif
Takes a little while to load on a slow connection.
Full article here: http://users.beagle.com.au/geoffsharp/
Geoff Sharp (07:18:16) :
The pattern matching is spot on, clearly showing the relationship.
you are off by half a cycle [at least as rendered by my browser]. Try again.
Robert Bateman (06:14:23) :
I’ll go with SIDC for their consistency
Where did SIDC get their numbers from? From Rudolf Wolf who got them from Staudacher. In Wolf’s first version of the SSN table, the Staudacher counts were low [as the GSN]. In 1861 he realized that the Staudacher counts were much too low and summarily doubled them. Later, in 1875 Wolf bumped all the numbers before 1849 up by another 25%, and sometime after 1880 Wolf took 50% off cycle 5. Finally about half of the monthly data for cycles 4 and 5 were simply made up.
Leif Svalgaard (08:08:43) :
Geoff Sharp (07:18:16) :
“The pattern matching is spot on, clearly showing the relationship.”
you are off by half a cycle [at least as rendered by my browser]. Try again.
Either my browser has changed its rendering or you have corrected the match-up. Now you can see that the sunspots appear on the poleward boundary of the yellow high zonal flow as was pointed out by Rachel Howe [and many others long ago].
Leif Svalgaard (06:48:11) :
I wrote the program that is used at WSO to calculate the spherical harmonics [that determine the flatness of the HCS].
BTW, if someone wants to see how it is done, my original derivation of the program is actually on my website: http://www.leif.org/research/Calculation%20of%20Spherical%20Harmonics.pdf . It is quite amazing that a 100 line program suffices.
Geoff Sharp (07:18:16) :
“The pattern matching is spot on, clearly showing the relationship.”
In your longer write-up you state
each flow will accommodate 2 cycles.
This is incorrect; each flow is for one cycle only. As Rachel points out [and has been known for a long time] the solar cycle is actually eighteen years long [makes playing with the lengths between statistical ‘minima’ rather meaningless].
Peter Taylor (04:54:47) :
To my uninitiated mind. there are no obvious causes in all this slow-changing dynamo dynamic. It looks as if something delivered a ’shock’ to the Sun’s system. Are there any electric currents out there sufficient to shock that system?
I thought I was only one interesting in current rather than flux, after all most of the magnetic fields are product of current flows. My hypothesis (declared as a nonsense, you have been warned) can be found on:
http://www.vukcevic.co.uk solar current link.
Robert Bateman (06:14:23) :
From DIGITIZATION OF SUNSPOT DRAWINGS BY STAUDACHER
The vertical lines are an indication for the error margin in that they are taken from the square root of the number of individual data points entering the average.
You [and or Arlt] are not understanding the meaning of ‘error’ here. ‘Error’ does not mean that the numbers can be wrong by that amount, but rather that there is variation within the interval [as you can see from a plot of the monthly data – or even more from plots of daily data]. The total area over a year would be exact with no error while still have a large variation from month to month within the year. The standard deviation of a count over an interval is approximated by the count itself [if the events are rare and independent – a so-called Poisson distribution], and the standard ‘error’ is customarily calculated as the standard deviation divided by the square root of the number of cases [minus 1 for the nit pickers]. Staudacher’s data are areas and not counts, but a ‘count’ can be approximated by assuming that each case has the same area. But a total area or count is always exactly what it is and has no error. You could as well calculate the ‘error margin’ of the standard SIDC yearly number by dividing by the square root of 365.
The Staudacher data is probably the very best data we have on what solar activity was back then. And, in fact the GSN and the SIDC/Wolf numbers are largely in a crude way based on the Staudacher data anyway.
“and I’ll go with David’s comparison
of SC23 with SC4, not because I agree with him, but because I found it independently, and nobody put the idea in my head.”
Again, you have company. The recognition has met congruent circumstances and been apprehended, independently, by very many.
What is surprising are the alternately contrived and vacuous arguments against. Clearly they protest too much.
“It looks as if something delivered a ’shock’ to the Sun’s system. ”
More apt: the shock abruptly abated.
from The American Association of Variable Star Observers (AAVSO)
“Solar activity before 1882 is lower than generally assumed, and consequently solar activity in the last few decades is higher than it has been for several centuries.
“There was a solar activity peak in 1801 and not in 1805, so there is no long anomalous cycle of 17 years as reported in the Wolf Sunspot Numbers. The longest cycle [in the record] now lasts no more than 15 years.
“The Wolf Sunspot Numbers have many inhomogeneities in them arising from observer noise, and this noise affects the daily, monthly, and yearly means. The Group Sunspot Numbers also have observer noise, but it is considerably less than the noise in the Wolf Sunspot Numbers.”
gary gulrud (09:20:52) :
Again, you have company. The recognition has met congruent circumstances and been apprehended, independently, by very many.
What is surprising are the alternately contrived and vacuous arguments against. Clearly they protest too much.
Ain’t that something, Gary?
We are not alone.
I’m just the layman here, paddling my own boat. I don’t have supercomputers or fancy models or spiffy equations ( I don’t understand that stuff anyways-I barely made it through pre-calculus).
Therefore, I cannot understand why I’m being shot at, I can only see what the official records show me.
I’m told don’t cherry pick. Ok. I’ll look at ALL of the neutron monitors.
I have gone out and visually verified L&P’s assertion of fading spots.
I pay attention to what is going on around me, like William Hershel the observer was want to do.
I didn’t change anybody’s records, though I am sorely tempted to use my Image processing skills to demonstrate that 30-45% of the microspots being used to pad todays SSN’s are SOHO only bogeys.
SIDC isn’t going to listen to a commoner like myself. Why should they?
I have no credentials to stand on.
So, I merely join the company of all those who see the pattern I do.
Others see it differently, I’m ok with that, let them protest.
I’ll do my protesting by saving my nickels & dimes and buy David’s book.