It has been awhile since I’ve looked at the Ap Index. The last time was April of 2009.
From the data provided by NOAA’s Space Weather Prediction Center (SWPC) you can see just how little Ap magnetic activity there has been since. Here’s my graph from September 2009 SWPC Ap data:
For a longer perspective, David Archibald, has a graph of the Ap Index back to 1932. The solar average geomagnetic planetary index, in Dec 2008, Ap was at its lowest level in 75 years:
Click for a larger image – I’ve added some annotation to the graph provided by Archibald to point out areas of interest and to clarify some aspects of it for the novice reader.
The last time the Ap index was this low was 1933. The December 2008 Ap value of 2,, has never been this low. (Note: Leif Svalgaard contends this value is erroneous, and that 4.2 is the correct value – either way, it is still lower than 1933) Further, the trend from October 2005 continues to remain low, though some signs of a slight rebound are showing.
This Ap index is a proxy that tells us that the sun is now quite inactive, and the other indices of sunspot index and 10.7 radio flux also confirm this. The sun is in a full blown funk, and your guess is as good as mine as to when it might pull out of it. So far, predictions by NOAA’s SWPC and NASA’s Hathaway have not been near the reality that is being measured.
As Leif Svalgaard points out, Ap is just one of several indices that describe geomagnetic activity. There are several others [aa, am, IHV, …] that go much further back in time [to the 1840s]. You can get more info from:
http://www.leif.org/research/IAGA2008LS.pdf and
http://www.leif.org/research/Seminar-UCLA-ESS288.pdf
For those that follow the sunspot number (SSN) I’ve graphed the Ap and SSN together. As you can see, we’ve been in a reduced state of solar activity now for quite some time. It has been almost 4 years since the prominent drop in Ap in October 2005. SSN mirrors the decline of the Ap index since then.
As many regular readers know, I’ve pointed out several times the incident of the abrupt and sustained lowering of the Ap Index which occurred in October 2005. The abrupt step change seemed (to me) to be out of place with the data, and since then the data seems less “active”, with reduced amplitudes. And then we have the fact that the sun seems to have reestablished at a lower plateau of the Ap index after that October 2005 step change and has not recovered now in almost 4 years. It seems to me to be a noteworthy event.
UPDATE: Thanks to Leif Svalgaard, we have a more extensive and “official” Ap dataset (NOAA’s SWPC has issues, see comments) that I’ve plotted below. The step change in October 2005 is still visible and the value of 3.9 that occurred in April of this year is the lowest for the entire dataset.
And I’ve also plotted the 1991 to present data from BGS/Svalgaard to compare against the NOAA SWPC data:
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Invariant (10:24:37) :
A. http://www.junkscience.com/MSU_Temps/Arctic75Nan.csv
Try to see if you can get temps for 2006-2008 too…
Leif Svalgaard (10:33:30) :
Yes! Another problem is that I would prefer monthly temperatures as the derivative is when time goes to zero. Possibly I need to smooth the data first too exactly as Ole Humlum has done
http://climate4you.com/Polar%20temperatures.htm#NH%2070-90%20TempSince1900
Does anyone know how I can get hold of the Arctic monthly surface air temperature anomaly 70-90N since January 1900?
Invariant (10:53:31) :
Yes! Another problem is that I would prefer monthly temperatures as the derivative is when time goes to zero.
HMF B only has one year resolution….
Invariant (10:53:31) :
you can get the temp data from a couple of places. Start with KMNI. or
go directly to a “source” like GISS or hadcru. You’ll need some skills, programming skills.
Leif Svalgaard (23:11:11)
Once again, the relative modulation of total GCR flux is not relevant to Svensmark et al’s hypothesis. Neither is the correlation between C14 production and temperature proxies a clear test.
As I noted in this thread previously, they point to the GCR that are strong enough to produce muons in the lowest 2km of the atmosphere as significant determinants of cloud cover, especially over oceans remote from land where condensation nuclei are more scarce. They calculate that as many 60 percent of such GCR are not deflected appreciably by the sun or the earth. Roughly 40 percent of such GCR are deflected by the sun’s magnetic field, but only about 3 percent are affected by the earth’s magnetic field.
As Leif notes at (23:11:11),The peak of 14C production is around 10 km altitude. For the GCR that affect the formation of 14C, therefore, the modulation of the earth’s magnetic field is relatively much greater.
Thus, data on total GCR flux, or the correlation between 14C and climate variables, does not directly bear on the validity of the Svensmark et al hypothesis.
So I return to the comments that started the discussion:
The original statement Leif was commenting on at 12:22:29 was:
Jewett (11:55:11) :
The increased cosmic rays results in increased clouds. The increased clouds increases the albedo of the earth, more energy from the sun is reflected into space and the earth cools.
which draws Leif’s comment:
The Sun’s magnetic field modulates the cosmic rays [GCR], and the Earth’s magnetic field does as well. The latter modulation is much larger than the former.
However, the comment that the earth’s magnetic field modulates the GCR more than the sun does not directly address Jewett’s point since implicitly he was talking about the high energy GCR that are modulated more by the sun by a factor of more than 10x.
The bottom line for this thread is, I think, that a low solar magnetic field should indeed provide a test of Svensmark’s hypothesis. It will be interesting to see how it works out. Does anyone know where the data on current low level cloud cover can be obtained easily?
Peter Hartley (11:39:37) :
Roughly 40 percent of such GCR are deflected by the sun’s magnetic field, but only about 3 percent are affected by the earth’s magnetic field.
That would mean that the modulation by the Sun and by the Earth would be of the same order of magnitude
the correlation between 14C and climate variables, does not directly bear on the validity of the Svensmark et al hypothesis.
So, it does bear directly.
And, the high-energy cosmic rays are rare. As I remarked, their number falls by roughly a factor of 1000 for an increase in energy of a factor of ten. What I don’t like about their argument is the Special Pleading. They need to have their mechanism to work with just the CRs that are modulated by the Sun and not by the Earth. Considering the steepness of the energy spectrum that is a very tight requirement. A final point is that the measurements we have of the albedo show that the variation of the albedo does not follow the solar cycle. Probably Svensmark and Co can find a special reason for why that doesn’t matter either [you know: the climate is a very complex system, etc, and one would not expect any direct correlation, and so on].
I do recognize that in the eyes of true believers none of my counter-arguments matter, the science is settled.
Peter Hartley (11:39:37) :
The bottom line for this thread is, I think, that a low solar magnetic field should indeed provide a test of Svensmark’s hypothesis.
We have good evidence that the HMF [heliomagnetic field] during solar cycle 23 [1996-2008] was very similar to the HMF during solar cycle 13 [1890-1901], so the cosmic ray flux [of whatever energy] should be similar too, and the temps as well, so on this account the hypothesis is falsified, unless yet another mitigating circumstance can be brought to bear.
Leif Svalgaard (12:08:14) :
“unless yet another mitigating circumstance can be brought to bear.”
Like a decrease(increase) in the interstellar flux
Leif (12:03:09) and (12:08:14):
Thank you — that has clarified your position (for me anyway) and I now see more clearly what your objections to the hypothesis are.
It seems to me that, given our improved ability to observe many of the relevant phenomena involved in the postulated mechanism, the data plotted at the start of this thread suggest that we are going to see a very good test of the hypothesis in the immediate future.
maksimovich (12:47:55) :
Like a decrease(increase) in the interstellar flux
And there are some indications of such a change, but throw that into the mix and you can fit almost anything, since the interstellar flux has to be deduced from the resulting modulation. And we also do not know if the energy spectrum has changed. But, with each new thing that can vary, the reported correlations become increasingly harder to take as evidence of anything.
Peter Hartley (12:50:16) :
the data plotted at the start of this thread suggest that we are going to see a very good test of the hypothesis in the immediate future.
I think that the HMF data going back ~170 years already provided such a test. I can’t see what in ‘the immediate future’ could change this.
Peter Hartley (12:50:16) : If you see the negative peak in GCR in 1991 with a correspondent low cloud cover (“The Chilling stars”, H.Svensmark, p.77) and subsequent 97-98 big El Nino, this time will be a re-check of the inverse phenomenon.
Dear Dr. Svalgaard,
According to the first law of thermodynamics,
dT/dt ~ Qin – Qout,
Here, Qin is heat added and Qout is head dissipated. When the magnetic field of the solar wind decreases Qin may be proportionally reduced due to increased cloud cover. Absolute temperature as such does not make sense, first because varying cloud cover (varying Qin) only affects dT/dt directly and second because the absolute temperature at times may be influenced by many other factors. Note also that there may be a significant delay of many years between changes in Qin and absolute temperature, due to the huge value of the time constant tau for the oceans,
T(t) = T1 + [T0 – T1] exp(-t/tau)
Here T0 the initial temperature, T1 the final temperature and tau the time constant. If we also approximate T with a sine function we observe that its derivative Qin should be the 90 degrees out of phase cosine function, which may partly explain why the magnetic field of the solar wind and the temperature may be out of phase.
Well, this is my understanding at the moment; I did not find the arctic surface data, but I encourage other readers of this blog to investigate any relationship between dT/dt and the magnetic field of the solar wind!
I think I never heard so loud
The quiet message in a cloud.
===================
Invariant (10:53:31) “Does anyone know how I can get hold of the Arctic monthly surface air temperature anomaly 70-90N since January 1900?”
KNMI Climate Explorer.
http://climexp.knmi.nl/start.cgi?someone@somewhere
” Leif Svalgaard (16:21:05) :
Jim Arndt (15:54:45) :
If Livingston and Penn are correct that means that Leif, Hathaway, Jansseen, Archibald, Hoyt are wrong…
L&P do not say that solar activity will go away, just that sunspots will be invisible because their magnetic field is [just?] below a value where the contrast is one. You see, magnetic fields below 1800 Gauss [or so] are bright, and above 1800 G are dark, so right at 1800 G, they cannot be seen, but they are still there. The solar cycle is still going, the dynamo is still working. No ‘re-do’ is needed.”
Sorry I was out with the Family to timely reply. That being said Leif you side stepped my question. The models and the observers (minus L&P) totally missed this. The models missed this. so something is wrong or the data is being mis-interpreted.
Jim Arndt (19:31:31) :
If the L&P keeps going, it could turn the spots white. What then becomes of the faculae & network? Do they turn dark in the visible or do they just keep getting brighter? Things like this bring up questions of fundamental change. Why would a star do this?
Leif Svalgaard (08:20:20) :
Geoff Sharp (07:31:47) :
“Exactly four”
Not a chance, surely you dont expect us to believe that.
Why don’t you actually read Pesnell’s paper that you lifted the Figure from…
You must think we are all stupid, your references in most cases do not back up your statements and are quite often wild goose chases. In this case you have deliberately mislead us by your statements. Conservatively over 54 predictions there would be at least 35 that follow the Babcock-Leighton model theory. Trying to associate only those that used a specific dynamo model as the only Babcock followers is farcical. By your logic you have excluded yourself from the Babcock list.
I will leave others to judge, the link to the full paper is here:
http://www.landscheidt.info/images/sc24_predictions.pdf
Are you saying Hathaway is not a Babcock believer? If you are right that doesn’t say much for the B-L theory.
———-
What it shows is that most of the predictions submitted to the panel were statistical/correlative in nature [including Hathaway’s], rather than based on physics.
Once again you are trying to mislead. Hathaway is a firm Babcock believer, the summary of his and Wilson’s prediction reads “Fast meridional circulation
speed during cycle 22 leads to a strong solar cycle 24”
Their prediction is listed under the “physics” heading
The great majority of the predictions are from those in the Babcock camp. It clearly shows the theory is in its death throws, unless of course we have a major upswing like they suggest.
I not not aware of any decent studies backing your claims
—————————
Your [willful] ignorance shows, perhaps I might refresh your memory: “Usoskin et al. (2007) performed a statistical analysis of grand-minima–occurrence time (Table 1) and concluded that their occurrence is not a result of long-term cyclic variations, but is defined by stochastic/chaotic processes.”
You dont need to refresh my memory, I use that paper in my own evidence, and its conclusions are nonsense. How can any paper on grand minima exclude Dalton type events? I’ll tell you, because the Babcock followers would then have to admit the sun has regular grand minima and their randomness theory is shot….Usoskin’s work has been useful, but his summary is blindly ridiculous.
Here is a graph showing how Usoskin should have done his graph:
http://www.landscheidt.info/images/c14nujs1.jpg
Grand Minima is about sunspots…no one ever said the solar cycle dies completely
———–
The various attempts to explain Grand Minima [including yours] operate with modulations or excitations of the dynamo or whatever drives the cycle. The L&P effect [and visibility of sunspots] is likely a surface phenomenon, that is: the cycle is still there, but the ability to concentrate enough flux in the active regions to bring them above the 1800G threshold that is required to make sunspots visible on the surface is impaired. And it is not sure that L&P actually operates, so far, the data is only suggestive.
Fluff and twaddle, the point of the exercise is SUNSPOTS, there is nothing new going on here. The other information is interesting but only a distraction.
Jim Arndt (19:31:31) :
The models and the observers (minus L&P) totally missed this. The models missed this. so something is wrong or the data is being mis-interpreted.
The models are concerned with ‘active regions’. That is, the magnetic areas in which sunspots are found. Whether the spots are visible is another matter. True, nobody anticipated the L&P effect [which still is a bit uncertain]. My own prediction of maximum sunspot number of 72, is really 72/12=6 active regions, visible or not. Put it differently, there is a strong correlation between the F10.7 radio flux and the sunspot number. My Rmax=72 corresponds to an F10.7 flux of 120, so equivalently, the prediction is of F10.7 = 120. This 120 does not depend on the visibility of the spots and should therefore not be influenced or ‘contaminated’ by any L&P effect.
rbateman (20:17:28) :
If the L&P keeps going, it could turn the spots white. What then becomes of the faculae & network? Do they turn dark in the visible or do they just keep getting brighter?
My guess is that the faculae and the network won’t change. One might speculate [wildly] that if there are are no dark spots, the TSI might actually be larger with the L&P effect. As this is unexplored territory, unexpected discoveries await us.
Dear Dr. Svalgaard,
Just found that the time integral of the magnetic field of the solar wind (HMF B) can be compared directly with the global temperature. In order to make the estimated temperature go up and down in the desired manner we need to find two parameters,
1. the equilibrium value of HMF B where Qin=Qout.
2. the scaling factor which converts HMF B “area” to temperature.
dT/dt ~ Qin – Qout,
These two parameters can for example be found by automatic curve fitting using a least squares method. Thinking about it, short cycles may contribute more to global warming since the cumulative contribution from two cycles with a short intermediate minimum is larger.
Leif 2:13:53
Don’t you mean that there has been a ‘strong correlation between the F10.7 radio flux and the sunspot number?’
========================================
Leif Svalgaard (12:08:14) :
We have good evidence that the HMF [heliomagnetic field] during solar cycle 23 [1996-2008] was very similar to the HMF during solar cycle 13 [1890-1901], so the cosmic ray flux [of whatever energy] should be similar too, and the temps as well, so on this account the hypothesis is falsified, unless yet another mitigating circumstance can be brought to bear.
I would be interested to see a graph depicting this occurrence. Is there something available?
kim (04:56:22) :
Don’t you mean that there has been a ’strong correlation between the F10.7 radio flux and the sunspot number?’
Yes, the correlation is changing, and if L&P is correct will break down, but up to perhaps ~2000 most people would say that it was pretty good, so that is what one might use as a base. The predictions of Rmax and F10.7max are all based on this relation. If we assume that the calibration of F10.7 has not changed [and independent measurements in Canada and Japan support that], then the predictions in terms of F10.7 should be good and not be affected by L&P. My colleague Ken Schatten has always predicted F10.7 instead of the SSN, and if I follow that lead, then my prediction if F10.7max = 120. Lots of people will make a lot of nonsense noise about this, along the lines of “but you said the SUNSPOT NUMBER would be 72” and not [some willfully] appreciate that the predictions are about the magnetic field in the active regions and not about the visibility of spots. Before L&P we thought that the SSN and F10.7 and the magnetic field were all equivalent and that one could one as a proxy for the other(s). Now we may have to be a bit more precise. This whole issue will cloud the discussion for decades to come.
Geoff Sharp (05:48:21) :
“We have good evidence that the HMF [heliomagnetic field] during solar cycle 23 [1996-2008] was very similar to the HMF during solar cycle 13 [1890-1901]”
I would be interested to see a graph depicting this occurrence. Is there something available?
I have shown this many times, but in case you missed it, you can find the it here [e.g. Figure 13]:
http://www.leif.org/research/IAGA2008LS-final.pdf
or slide 12 of http://www.leif.org/research/AGU%20Spring%202008%20SH44A-02.pdf
or page 9 of http://www.leif.org/research/AGU%20Fall%202008%20SH24A-01.pdf
We believe that the increase in solar wind speed [e.g. seen in slide 12 of the second reference] is not real, but is a result of the decrease of the Earth’s magnetic field that makes it more sensitive to the solar wind disturbances, but this is still an open research question.
Invariant (03:40:55) :
These two parameters can for example be found by automatic curve fitting using a least squares method.
Keep working on it…