Scientists find errors in hypothesis linking solar flares to global temperature
From Physorg.com. h/t to Leif Svalgaard who offers this PDF with this diagram that makes it all clear.
In contrast to a previous analysis, a new study has shown that the distributions of (a) the global temperature anomaly by month since 1880 and (b) the solar flare index by day over a few solar cycles are fundamentally different. One feature the detrended data do have in common is self-similarity: the probability density functions are the same on different time scales, which means that neither can be described as Lévy walks. Image credit: Rypdal and Rypdal.
(PhysOrg.com) — The field of climate science is nothing if not complex, where a host of variables interact with each other in intricate ways to produce various changes. Just like any other area of science, climate science is far from being fully understood. As an example, a new study has discredited a previous hypothesis suggesting the existence of a link between solar flares and changes in the earth’s global temperature. The new study points out a few errors in the previous analysis, and concludes that the solar and climate records have very different properties that do not support the hypothesis of a sun-climate complexity linking.
In a handful of studies published in Physical Review Letters between 2003 and 2008, a team from Duke University and the Army Research Office including Nicola Scafetta and Bruce West analyzed data that appeared to show that solar flares have a significant influence on global temperature. Solar flares, which are large explosions in the sun’s atmosphere that are powered by magnetic energy, vary in time from a few per month to several per day. Although solar flares occur near sunspots, their frequency variation occurs on a much shorter time scale than the 11-year sunspot cycle. In their studies, the researchers’ results seemed to show that data from solar flare activity correlates with changes in the global temperature on a short time scale. Specifically, their analysis showed that the two time records can both be characterized by the same Lévy walk process.
However, in the new study, which is also published in Physical Review Letters, Martin Rypdal and Kristoffer Rypdal of the University of Tromso in Norway have reexamined the data and the previous analysis and noticed some shortcomings. One of the biggest causes of concern is that the previous analysis did not account for larger trends in factors that affect solar flares and global temperature. For instance, the solar cycle has its 11-year periodic trend, where periods of lots of sunspots cause larger numbers of solar flares. Likewise, the global temperature anomaly has numerous other factors (a “multi-decadal, polynomial trend”) that impacts global temperature fluctuations. By not detrending this data, the analysis resulted in abnormally high values of certain variables that pointed to Lévy walk processes. By estimating the untrended data, Rypdal and Rypdal hypothesized that the solar flare records might be described by a Lévy flight, while the global temperature anomaly might obey a distribution called persistent fractional Brownian motion.
Read the entire article here at Physorg.com
A preprint of the paper is available here
Practice making your own Levy walks here
Considering the complexity of the mechanisms interposed by the Earth system between incoming solar energy, an effect on tropospheric temperature (which is all they are really considering) and then departure of energy from the system this article is a pitifully inadequate attempt to distract from the very idea that solar effects could be significant without having to go to much effort or expense.
For what it’s worth my view is that they are probably right about short timescales where chaotic variability overlays and obscures the lesser solar and oceanic cycles but almost certainly wrong on longer timescales from say 500 years or more which lead to the longer term climate cycling from events such as the Mediaeval Warm Period to Little Ice Age to the current Modern Warm Period.
A lazy and disingenuous piece of work in my opinion.
The authors try to correlate in a short term way, but indirectly, sunspots with climate – an exercise in hubris. But we have seen so many times before with climate “correlations” that these are multivariate and polynomial, not linear, since the primary effects are modulated by secondary buffering effects, leading to lag times. These lag times then are superimposed on other primary factors, also with lag times, leading to polynomially related sinusoidal stacking of cycles.
In other words, their are so many sinks that modulate effects of sun, cosmic rays, water and sea cycles, tectonics, orientation and position of the earth, etc., leading to many equations with many unknowns. It is a fool’s errand to try to simplify.
Its in part 3 of 6.
http://www.youtube.com/redirect?username=AnonH5N1&q=http%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DeQSy4NFKZko&video_id=eQSy4NFKZko&event=url_redirect&url_redirect=True&usg=L0R1ry6O9Bo7YVOUK3wsZomhKPE=
@ur momisugly Leif Svalgaard (10:20:25) :
Hmm, I wasn’t appealing to ignorance to dispute the paper, but instead asking a question. That question was, what other things could cause the climate to vary as it did in the MWP and LIA if it wasn’t the sun, and wasn’t GHGs? I thought the sun was the favored explanation for LIA?
The logical fallacies only apply to debates, not questions, or every question would be an appeal to ignorance, and science the art of appealing to ignorance, no? 😉
Where at Minute 2:30 a visit to a river: The IGuato River (sp?) by Argentinian physicist Pablo Mauas (sp?) has found the ‘shethru’ (can’t make out what he says actually) goes up and down 3 times during that last century following sun spot levels beautifully (a scientific way of saying ‘so robustly you can’t deny it!).
Hi Leif, the authors note that there is only a monthly GTA available.
That’s not precisely true. There is a substantial daily global record
(23,000 stations ) available ( with different spatial coverage ) With some of the new methods ( RomanM and JeffId) that people are using to construct
GTAs ( getting rid of the Common Anomaly period which requires 20 years of data in the period 1961-90 ) it may be possible
to construct a good daily record for the globe for the past 40 years
or so. I havent discussed this with Jeff or Roman ( their method currently
works on Monthly data ) but it strikes me that some solar studies would
benefit from a higher resolution ( but shorter time period) GTA. Not sure.
Also, I’m wondering if they could also getting a better look at things by
considering Tmax only.
Chaos breeds strange attractors. That the fractal horse head in the scribble is replicated through dimensions is not accidental. Random is an imaginary concept, chaos is a real phenomenon. Science is still in its infancy.
Not every solar cycle is eleven years from start to
finish. Also, some solar cycles overlap the one before, the one
after, or both.
Not every sunspot produces a flare. Not every
flare comes from a sunspot.
The level of solar activity may have a +/- cumulative
effect on earth atmospheric temperatures, but with a lag time
that takes the change beyond one cycle and into the next.
I don’t think “discredited” applies to all possible instances…
and solar flares may only be one form of solar output that
impacts our atmospheric temps.
This final concluding paragraph from the Phys.org article is revealing of the mind set of the authors of the scientific paper in the post:
“The theory of anthropogenic global warming consists of a set of logically interconnected and consistent hypotheses,” Martin Rypdal said. “This means that if a cornerstone hypothesis is proven to be false, the entire theory fails. A corresponding theory of global warming of solar origin does not exist. What does exist is a set of disconnected, mutually inconsistent, ad hoc hypotheses. If one of these is proven to be false, the typical proponent of solar warming will pull another ad hoc hypothesis out of the hat. This has been the strategy of Scafetta and West over the years, and we have no illusion that our paper will put them to silence. However, the only scientifically valid strategy to confront these new hypotheses is to shoot down every new missile as they come in, using the most advanced weapons at hand. We believe that this operation was successfully accomplished with respect to the complexity linking hypothesis, but there will be many more battles to be fought until the issue of the contribution of solar variability to recent global warming is settled.”
http://www.physorg.com/news189845962.html
To highlight: “However, the only scientifically valid strategy to confront these new hypotheses is to shoot down every new missile as they come in, using the most advanced weapons at hand.”
While it’s admirable that the scientists are so up-front with their goals and purposes, this kind of pointed “outcome” oriented agenda should make readers cautious when considering what weight to give the conclusions of this paper and other papers who’s authors state similar “outcome” oriented agendas.
All solar flares don’t impinge on earth … The need for more information is obvious.
johnythelowery (10:07:41) :
Is this something to worry about? Is CO2 doing the changing? The global warming you refer to: Is this the AGW ‘global warming’ or the general warming. (I assume we all agree there is warming)?
Compositional changes does affect the stratosphere. This does not mean that that change propagates downwards to change the surface, which is [as far as I can ascertain] what Steve Wilde claims.
Stephen Wilde (10:24:13) :
A lazy and disingenuous piece of work in my opinion.
You must, of course, be referring the S&W’s work. That is the whole point of R&R’s rebuttal.
bubbagyro (10:26:58) :
The authors try to correlate in a short term way, but indirectly, sunspots with climate – an exercise in hubris.
Again, you must be referring to S&W and not R&R
Dave F (10:45:33) :
@ur momisugly Leif Svalgaard (10:20:25) :
Hmm, I wasn’t appealing to ignorance to dispute the paper, but instead asking a question.
I was not referring specifically to ignorance on your part, but to the general fallacy behind “what else can it be?”. just because we don’t know another explanation, does not make the one we have correct.
I thought the sun was the favored explanation for LIA?
The problem there is that the Sun and the temperatures don’t really vary in phase. Here is a comparison between temps and TSI [a general measure of solar activity]: http://www.leif.org/research/Loehle-Temps-and-TSI.png
As you can see there is very little similarity.
steven mosher (10:58:19) :
Hi Leif, the authors note that there is only a monthly GTA available.
That’s not precisely true.
R&R just follow S&W here. If daily GTA is available [notwithstanding all the folks that a Global Temperature is absurd 🙂 ], then daily sunspot numbers numbers are available back to 1818. A worthwhile project for the enthusiasts to embark upon.
Have to agree with bryan, the two graphs do not cover the same time frame 1500 months is approximately 45000 days, not 15000 as the second graph shows. Could be a typo, but if thats the case, then it demonstrates a certain lack of attention to detail.
“These results provide strong evidence that the stochas-
tic properties of the temperature record are governed by
the long-memory internal dynamics of the climate sys-
tem and are not linked to the short-memory intermittent
fluctuations which characterize the solar output.”
for those of you commenting on the “brownian motion” aspect, you
need to realize that they detrended the data with a 4th order poly
that represented the decadal variations ( read oceanic cycles) in the
data. S&W missed this step and its fairly well known that to estimate
H ( Hurst ) you need to take care, as these authors did.
R.S.Brown (11:00:00) :
I don’t think “discredited” applies to all possible instances…
and solar flares may only be one form of solar output that
impacts our atmospheric temps.
And yet S&W claims that flares [or what they are a proxy for] control more than 60% of the climate variation. This is what the paper of this topic refutes.
jnicklin (11:20:44) :
Have to agree with bryan, the two graphs do not cover the same time frame 1500 months is approximately 45000 days, not 15000 as the second graph shows. Could be a typo, but if thats the case, then it demonstrates a certain lack of attention to detail.
If I’m not mistaken that lack of attention is S&W’s, but someone check up on me on that.
So if it isn’t the sun affecting the climate according to sun spot data, why is the
the Iguato River (sp?) in the Amazon river basin as analysed by Argentinian physicist Pablo Mauas (sp?) , tracking sun spot levels beautifully?
The connection is………………….
Well, there isn’t according to this article. But as we know there is, perhaps it’s to do with the photon itself. Is everything to be known about the photon…known?
DIdn’t the maunder minimum settle this issue? It is too early to tell about our current dead sun (Eddy minimum).
We only see the flares when the sun is facing us, but, when they could occur
around the otherside into the solar wind and blow back on us…without us seeing the flare, that could ramp up the intensity of the radiation without a corresponding flare obversation? Does a flare which propogates on the otherside, necessarily be there when that location rotates to face us, and therefore, us to observe the flare?
James F. Evans (11:08:41) :
While it’s admirable that the scientists are so up-front with their goals and purposes
I think you miss the point. Their statement is not about goal and purpose, but about proper scientific analysis: if there are scores of claims, then the way to separate the wheat from the chaff, is to get rid of the chaff. If a theory survives in spite of persistent attempts to shoot it down, then we gain confidence in it. And that is the goal and purpose.
Actually, I like ‘Leif’s Eddy minimum’!
I like the Eddy bit too as it sounds like a river that’s about to conk out!
@Leif 10:20:25
Yes, the Oort was in the MWP, but brief and mild. Wolf, Sporer and Maunder were all “stronger” minima, and associated with LIA.
http://en.wikipedia.org/wiki/Sp%C3%B6rer_Minimum
johnythelowery (11:29:10) :
the Iguato River (sp?) in the Amazon river basin as analysed by
For every river that does, there is one that doesn’t 🙂
There is a selection effect here. If I take 100 rivers, and analyze them then about 5 should show an effect on at the 95% confidence level. If I only publish the ones that do and ignore the rest [after all, they can’t be too interesting since they show no effect], you have a nice selection effect.
Leif Svalgaard (10:20:25) :
the MWP had the Oort Grand Solar Minimum smack in the middle of it.
And the dryest years contain record lows along with record highs.
Long dry spells give way to deluges in the same manner as flipping the light switch. Climate (and Weather) are full of stark and adjacent contrasts as well as longstanding slopes in both directions.
Yes, the records bear out that these oppositions are in microcosm and macrocosm. There are also relatively quiescent periods.
The model I would propose would test out even/odd numbers of drivers that can oppose or be caused to oppose, override/be overriden or be caused to overide/be overriden, as well as operate in either short or long terms cycles. Throw in some ellipticity to their strengths. That should make a wild output.
Reminds me of Paul Klee, the Swiss painter, “taking a line for a walk”.
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I referred to S&W, correct.
As to the shooting of missiles as they appear, this is the ABSOLUTE goal of science. Mr. Evans may not be a scientist, but our goal as scientists is to attack (nullify) every new hypothesis. Withstanding such attacks over time leads to theory. We expect our own hypotheses to be nullified; this we not ony deserve, but expect and embrace.