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
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Can’t fool me — that’s the Catlin 2010 track.
Wasn´t it that the sun, that shiny and round thing up there used to warm the earth?. This is really Ravetz´s PNS…
Let it shine, let it shine, let it shine… ♪♪♪
What we see here is the beginning of a LONG conversation. This smells a bit like the campaign to get rid of the MWP to me.
hehe
Yep that diagram makes it all clear.looks like a toddler’s drawing.
They drew the squiggly lines wrong,should have drawn them this way.
Sorry,couldn’t resist,I know it’s important scientific stuff.I’ll stop now.
As long as GTA is used, nothing will be explained. The moment GTA will be dropped for what it is -irrelevant to climatic changes, at least when taken within its present day variations range-, research will advance.
From the paper:
We were very surprised that Scafetta and West never show such results in their papers. It seems that they have designed all their tests with the purpose of proving a wanted result, and deliberately avoided analysis that points in other directions.
I’m surprised that they are surprised. This suggests they haven’t been following the posts and comments on WUWT and other sites. Someone send them a link!
The first thing that strikes me is the GTA graph. How does anyone determine and anomaly of global temp? To do so would require one to know what the normal global temp is. We all know from the geologic record how much temperatures fluctuate globally. So to me the GTA as described here is unknowable.
The correct method of analogy here would be to compare solar flare index to the global temperature record as known through proxies as they would give an accurate look at what global temperature was doing over the period.
So this whole post to me is garbage based on inaccurate global temperature analysis.
Plotting flares (bell bottoms) and miniskirts as correlations to the rise and fall of the stock market. Why not.
Just remember, when we see superstition carry a huge weight in long term warming trends of a hockey stick nature, it is taboo to admit to being superstitious.
Looks like the journalist at Physorg has fallen into a popular statistical beartrap:
“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”. Physical phenomena are generally only described by distributions, rather than obeying them, as the paper itself indicates.
David S (09:43:02) :
Physical phenomena are generally only described by distributions, rather than obeying them, as the paper itself indicates.
Same trap Scafetta and West were in, if we want to go that route. My own criticism of Scafetta and West is that they used flare counts [as they lamely note are ‘a proxy for the sunspot number’] when they could have used sunspot numbers directly.
Looks like Pooh Bear did the diagram!
Actually, the author of the published story, Lisa Zyga (and maybe the researchers ?), claim:
As the researchers explain, the results provide more evidence to support the supposedly controversial theory of human-induced global warming.
This seems to be false logic of the “it does not follow” type (non sequitur).
noelene — Yep that diagram makes it all clear.
Indeed. I looked it up. Best I can make out, if it were a Levy flight this would suggest resonance, but brownian motion suggests randomness. If resonance then it’s related; if brownian it’s not. And even then I could be utterly wrong.
http://en.wikipedia.org/wiki/L%C3%A9vy_flight
and here
http://en.wikipedia.org/wiki/Cauchy_distribution
Is this Levy track a fractal one?
The chaotic behavior of the system has only been seen for a very brief interval yet mathematicians without knowing the interrelationships of the variables claim they can define a pattern?
Can one use an elastic metric like GTA and base a hypothesis on a ‘polynomial’ which has terms some of which are unknown and which interact in unknown ways, that has been studied over a brief period in which some polynomials have not fully cycled?
Further on in the article is this: “As the researchers explain, the results provide more evidence to support the supposedly controversial theory of human-induced global warming.”
I don’t like statements like this. The paper may in fact refute Scafetta and West, but refuting this hypothesis doesn’t generate evidence for AGW. In fact, I would think that showing that the GTA exhibits “persistent fractional Brownian motion” would suggest the opposite. Brownian increments are supposed to be random, independent, and equally likely to occur in either direction. How does this correlate with constantly increasing GHG concentration?
So if the sun has an even smaller effect, then what caused the MWP? The LIA?
Mike Clark (09:41:17) :
The first thing that strikes me is the GTA graph.
The GTA data is the one used by S&W [Scafetta & West] and just about everybody else in this game. So GIGO [if that is what you advertise] starts with S&W.
John F. Hultquist (09:51:42) :
This seems to be false logic of the “it does not follow” type (non sequitur).
If we are not distracted by that nonsense [likely injected by the journalist] the paper by R&R ends much more reasonably: “The results provide strong evidence that the stochastic properties of the temperature record are generated by the long-term memory internal dynamics of the climate system and are not linked to the short-memory intermittent fluctuations which characterize the solar output”.
LIEF: are you concerned about CO2 concentrations and emmissions? You said this over on another thread which caught by attention. Just wanted to clarify this
————————————————————-
Leif Svalgaard (10:50:22) :
Stephen Wilde (10:18:46) :
You could just have said that the expansion of the atmosphere below the thermosphere is insignificant but then it still wouldn’t be zero would it ?
If we put the lower border of the thermosphere at 100 km, then the expansion of everything below that would be precisely zero.
Where does that leave your assertion about the effect of more UV ?
This has been established for decades. See e.g. http://solarphysics.livingreviews.org/Articles/lrsp-2007-2/
There has been a long-term [i.e. not solar cycle related] change in stratospheric temperature, attributed to chemical composition changes [and Global Warming, even]
8042010 Leif Svalgaard (10:51:01)
————————————————————-
This last statement. About the Stratospheric Temp, attributed to chemical changes, and global warming even….
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)?
Oopps. My apologies Leif. It’s Leif not Lief. Sorry.
R. Craigen (09:22:46) :
“What we see here is the beginning of a LONG conversation. This smells a bit like the campaign to get rid of the MWP to me.”
I’m betting that the purpose of the paper is to keep variations in the sun’s output out of the discussion, which is kind of suspicious, as without the sun we wouldn’t be having a climate at all. It may well be that there is no direct coupling between solar explosions and the weather, but one might want to analyze the impulse response of the earth’s magnetosphere and ionosphere to the blasts, and then look at other coupling mechanisms. Maybe we’ve lucked out, and the Earth’s weather patterns are immune to solar strobes. As long as the science is good, we’ll survive, we just can’t take any more frauds.
The two graphs might indicate more similarity if they were displayed in the same timeframe. but the Solat Flare index is displayed at 15000 days and the Global temp is displayed at 45000 days (figuring a rough 30 days per month)
Dave F (10:00:36) :
So if the sun has an even smaller effect, then what caused the MWP? The LIA?
This is another example of false logic. The “appeal to ignorance”: ‘What else can it be? BTW, the MWP had the Oort Grand Solar Minimum smack in the middle of it.
I will accept this analysis.
Now go back and follow the same standards and procedures to connect CO2 and temperature for a period longer than 2000 years.