Nicola Scafetta sent me this paper yesterday, and I read it with interest, but I have a number of reservations about it, not the least of which is that it is partially based on the work of Landscheidt and the whole barycentric thing which gets certain people into shouting matches. Figure 9 looks to be interesting, but note that it is in generic units, not temperature, so has no predictive value by itself.
While that looks like a good hindcast fit to historical warm/cold periods, compare it to figure 7 to see how it comes out.
Now indeed, that looks like a great fit to the Ljungqvist proxy temperature reconstruction, but the question arises about whether we are simply seeing a coincidental cyclic fit or a real effect. I asked Dr. Leif Svalgaard about his views on this paper and he replied with this:
The real test of all this cannot come from the proxies we have because the time scales are too short, but from comparisons with other stellar systems where the effects are calculated to be millions of times stronger [because the planets are huge and MUCH closer to the star]. No correlations have been found so far.
See slide 19 of my AGU presentation:
http://www.leif.org/research/AGU%20Fall%202011%20SH34B-08.pdf
So, it would seem, that if the gravitational barycentric effect posited were real, it should be easily observable with solar systems of much larger masses. Poppenhager and Schmitt can’t seem to find it.
OTOH, we have what appears to be a good fit by Scafetta in Figure 7. So this leaves us with three possibilities
- The effect manifests itself in some other way not yet observed.
- The effect is coincidental but not causative.
- The effect is real, but unproven yet by observations and predictive value.
I’m leaning more towards #2 at this point but willing to examine the predictive value. As Dr. Svalgaard points out in his AGU presentation, others have tried but the fit eventually broke down. From slide 14
P. D. Jose (ApJ, 70, 1965) noted that the Sun’s motion about the Center of Mass of the solar system [the Barycenter] has a period of 178.7 yr and suggested that the sunspot cycles repeat with a similar period. Many later researchers have published variations of this idea. – Unfortunately a ‘phase catastrophe’ is needed every ~8 solar cycles
Hindcasting can be something you can easily setup to fool yourself with if you are not careful, and I’m a bit concerned over the quality of the peer review for this paper as it contains two instances of Scafetta’s signature overuse of exclamation points, something that a careful reviewer would probably not let pass.
Science done carefully rarely merits an exclamation point. Papers written that way sound as if you are shouting down to the reader.
The true test will be the predictive value, as Scafetta has been doing with his recent essays here at WUWT. I’m willing to see how well this pans out, but I’m skeptical of the method until proven by a skillful predictive forecast. Unfortunately it will be awhile before that happens as solar timescales far exceed human lifespan.
Below I present the abstract, plus a link to the full paper provided by Dr. Scafetta.
=============================================================
Multi-scale harmonic model for solar and climate cyclical variation throughout the Holocene based on Jupiter–Saturn tidal frequencies plus the 11-year solar dynamo cycle
ScienceDirect link
Nicola Scafetta, ACRIM (Active Cavity Radiometer Solar Irradiance Monitor Lab) & Duke University, Durham, NC 27708, USA
Abstract
The Schwabe frequency band of the Zurich sunspot record since 1749 is found to be made of three major cycles with periods of about 9.98, 10.9 and 11.86 years. The side frequencies appear to be closely related to the spring tidal period of Jupiter and Saturn (range between 9.5 and 10.5 years, and median 9.93 years) and to the tidal sidereal period of Jupiter (about 11.86 years). The central cycle may be associated to a quasi-11-year solar dynamo cycle that appears to be approximately synchronized to the average of the two planetary frequencies. A simplified harmonic constituent model based on the above two planetary tidal frequencies and on the exact dates of Jupiter and Saturn planetary tidal phases, plus a theoretically deduced 10.87-year central cycle reveals complex quasi-periodic interference/beat patterns. The major beat periods occur at about 115, 61 and 130 years, plus a quasi-millennial large beat cycle around 983 years. We show that equivalent synchronized cycles are found in cosmogenic records used to reconstruct solar activity and in proxy climate records throughout the Holocene (last 12,000 years) up to now. The quasi-secular beat oscillations hindcast reasonably well the known prolonged periods of low solar activity during the last millennium such as the Oort, Wolf, Spörer, Maunder and Dalton minima, as well as the 17 115-year long oscillations found in a detailed temperature reconstruction of the Northern Hemisphere covering the last 2000 years. The millennial three-frequency beat cycle hindcasts equivalent solar and climate cycles for 12,000 years. Finally, the harmonic model herein proposed reconstructs the prolonged solar minima that occurred during 1900–1920 and 1960–1980 and the secular solar maxima around 1870–1890, 1940–1950 and 1995–2005 and a secular upward trending during the 20th century: this modulated trending agrees well with some solar proxy model, with the ACRIM TSI satellite composite and with the global surface temperature modulation since 1850. The model forecasts a new prolonged solar minimum during 2020–2045, which would be produced by the minima of both the 61 and 115-year reconstructed cycles. Finally, the model predicts that during low solar activity periods, the solar cycle length tends to be longer, as some researchers have claimed. These results clearly indicate that both solar and climate oscillations are linked to planetary motion and, furthermore, their timing can be reasonably hindcast and forecast for decades, centuries and millennia. The demonstrated geometrical synchronicity between solar and climate data patterns with the proposed solar/planetary harmonic model rebuts a major critique (by Smythe and Eddy, 1977) of the theory of planetary tidal influence on the Sun. Other qualitative discussions are added about the plausibility of a planetary influence on solar activity.
Link to paper: Scafetta_JStides
UPDATE 3/22/2012 – 1:15PM Dr. Scafetta responds in comments:
About the initial comment from Antony above,I believe that there are he might have misunderstood some part of the paper.
1)
I am not arguing from the barycentric point of view, which is false. In the paper I am talking
about tidal dynamics, a quite different approach. My argument
is based on the finding of my figure 2 and 3 that reveal the sunspot record
as made of three cycles (two tidal frequencies, on the side, plus a central
dynamo cycle). Then the model was developed and its hindcast
tests were discissed in the paper, etc.
{from Anthony – Note these references in your paper: Landscheidt, T.,1988.Solar rotation,impulses of the torque in sun’s motion, and
climate change. Climatic Change12,265–295.
Landscheidt, T.,1999.Extrema in sunspot cycle linked toSun’s motion. Solar
Physics 189,415–426.}
2)
There are numerous misconceptions since the beginning such as “Figure 9 looks to be interesting, but note that it is in generic units, not temperature, so has no predictive value by itself.”
It is a hindcast and prediction. There is no need to use specific units, but only dynamics. The units are interpreted correctly in the text of the paper as being approximately W/m^2 and as I say in the caption of the figure “However, the bottom curve approximately reproduces the patterns observed in the proxy solar models depicted in Fig. 5. The latter record may be considered as a realistic, although schematic, representation of solar dynamics.”
{from Anthony – if it isn’t using units of temperature, I fail to see how it can be of predictive value, there is not even any reference to warmer/cooler}
3) About Leif’s comments. It is important to realize that Solar physics is not “settled” physics. People do not even understand why the sun has a 11-year cycle (which is between the 10 and 12 year J/S tidal frequencies, as explained in my paper).
4)
The only argument advanced by Leif against my paper is that the phenomenon is his opinion was not observed in other stars. This is hardly surprising. We do not have accurate nor long records about other stars!
Moreover we need to observe the right thing, for example, even if you have a large planet very close to a star, the observable effect is associated to many things: how eccentric the orbits are and how big the star is, and its composition etc. Stars have a huge inertia to tidal effects and even if you have a planet large and close enough to the star to produce a theoretical 4,000,000 larger tidal effect, it does not means that the response from the star must be linear! Even simple elastic systems may be quite sensitive to small perturbations but become extremely rigid to large and rapid perturbations, etc.
It is evident that any study on planetary influence on a star needs to start from the sun, and then eventually extended to other star systems, but probably we need to wait several decades before having sufficiently long records about other stars!
In the case of the sun I needed at least a 200 year long sunspot record to
detect the three Schwabe cycles, and at least 1000 years of data for
hindcast tests to check the other frequencies. People can do the math for how long we need to wait for the other stars before having long enogh records.
Moreover, I believe that many readers have a typical misconception of physics.
In science a model has a physical basis when it is based on the observations
and the data and it is able to reconstruct, hindcast and/or forecast them.
It is evident to everybody reading my paper with an open mind that under the scientific
method, the model I proposed is “physically based” because I am
describing and reconstructing the dynamical properties of the data and I
showed that the model is able to hindcast millennia long data records.
Nobody even came close to these achievements.
To say otherwise would mean to reject everything in science and physics
because all findings and laws of physics are based on the observations and
the data and are tested on their capability of reconstruct, hindcast and/or
forecast observations, as I did in the paper
Of course, pointing out that I was not solving the problem using for example
plasma physics or quantum mechanics or whatever else. But this is a complex
exercise that needs its own time. As I correctly say in the paper.
“Further research should address the physical mechanisms necessary to
integrate planetary tides and solar dynamo physics for a more physically
based model.”
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tallbloke says:
March 25, 2012 at 2:18 pm
the 10.8 year component and the ~122 year harmonic are internal to the Sun, and these control the dynamo, and the 9.93 year and 11.86 year sideband frequencies arise as a necessary result of these fundamental periods. In other words, he proposes an identical model to Nicola Scafetta’s, but claims that the 9.93 year component and the 11.86 year component only happen to match the tidal period of Jupiter and Saturn and Jupiters orbital period by pure coincidence.
The model is very different as it does not invoke any tidal periods, but simply an amplitude modulation of the fundamental dynamo.
he is now calling Copernicus and Kepler numerologists.
Kepler most certain was: http://www.georgehart.com/virtual-polyhedra/kepler.html
So much for pseudo-science. The Dynamologists have offered no model which accounts for the 1.3 year countervailing speeding and slowing of the two layers near the solar tachocline
But they know their solar physics, the 1.3 year thingy was a temporary fluke in messy data, and has gone away:
http://iopscience.iop.org/1742-6596/271/1/012075/pdf/1742-6596_271_1_012075.pdf
“After 15 years of GONG and MDI observations of the solar interior rotation, we
revisit the issue of variations in the rotation rate near the base of the convection zone. The
1.3-year period seen in the first few years of the observations disappeared after 2000 and has
still not returned”
and can’t predict solar activity or hindcast it with any model dynamo
Predicted cycle 24 quite nicely [and actually cycles 21, 22, and 23 too]. Hindcasting you can always do by curve fitting.
@All: “God does not play dice”, Albert Einstein
adolfogiurfa says:
March 25, 2012 at 5:27 pm
@All: “God does not play dice”, Albert Einstein
“He most certainly does, and even throws them where we can’t see them”, me
Terry Oldberg said @ur momisugly March 25, 2012 at 3:55 pm
I do not, based on my recollection of Popper’s argument in LScD, see where it has been mischaracterised by Sober. Indeed, citing Popper’s argument in regard to another of Popper’s argument seems to me to be the very antithesis of Aunt Sally.
I am also dubious about your appeal to the frequentist interpretation of probability on the grounds that nobody has had, or ever will have, the time to perform an infinite number of coin tosses. I recall here RA Fisher’s remark, made it seems with the courage of despair, “in a hypothetical infinite population the ratio is perfectly definite”. (Phil Trans 222 A, 1922 p312).
The Pompous Git:
You’ve jumped to the wrong conclusion. I’ve not made the frequentist interpretation of probability.
tallbloke says:
March 25, 2012 at 2:18 pm
[….]
Thank you for honouring me with such a kind and detailed response, Tall Bloke. Please feel free to call me Peter, btw. In re-reading my posts, I recognize that I did, er, well, jump to a few little assumptions, strayed a bit outside the bounds of courtesy and in retrospect, I think I might have done better to have addressed you with my questions and concerns directly. Funnily enough, with all the talk about predictions, projections and forecasts, no one noticed my bulls-eye prediction that you would make an appearance to hand my arse on a platter. I just didn’t know how it would be cooked, but I don’t have a ready access to a Cray.
Regarding Dr Scafetta’s paper I will now have to justify your confidence in my capacity to comprehend the science behind the issues by straining my brain even more. I will read your outline, the arguments and counter-arguments of the others and even struggle through the paper one more time. That’ll occupy my leisure hours for a good part of the coming week. With this single posting, I have actually learned quite a bit about an area that’s far, far outside my usual intellectual haunts. I don’t have any illusions about attaining the kind of depth and detail I see here, but I should be able to reach a general understanding of the topic, which will make me even more insufferable. My own areas of competence are in marketing, digital and traditional art and illustration and the closest I have come to anything scientific has been my writing and editing on brick and stone masonry, having a couple of years ago co-edited, co-authored, fully illustrated and page-formatted the first uniquely Canadian text book on brick and stone masonry. With about a dozen of committee members, technical instructors and university engineering departments overseeing all, I’ve truly tasted peer review at its “finest” and have a few grey hairs to prove it too.
Thanks for addressing my comments, I see you are taking your auto de fe rather cheerfully. And you’re right, much of this way beyond a layman’s ken, but a few comments from the peanut gallery. This pertains to the first and second claims, which in retrospect O could have rolled into one. If there is one thing I sort of got as I rooted around in my new scientist persona, it’s a table of gravitational forces which indicated the Moon as the strongest force, numerically represented with the numeral 2, followed by the Sun as 2, and then fractions of a percent for the planets. The argument some have made, if I understood things, is that in comparison to the influence of the Moon, which exerts a pretty powerful effect on large bodies of water and even (what a freaky thing, that) creates Earth tides, the forces exerted by the planets are inconsequential. The other point of confusion I’ll mention now is “controlling feedback mechanisms,” and “harmonic arrangements.” I’m under the impression that the former is not physically evident and directly measurable…as with the machine that goes “beep,” to borrow from Monty Python…and the latter reminds me of the Renaissance search for mathematically and rationally expressed arrangements in nature. My bias here is at play, in that as a religious fellow I’m familiar with such arguments, but in my efforts to separate science, from faith, my rationalistic half doth protest. However, I do need to look up a few things as you say, and if I get a handle on something, be sure that I’ll proudly flaunt it.
Once again, thank you for taking the time and effort to explain, Tall Bloke. It is not a wasted effort, surely not on others here who have a better grasp, but on me as well, as it spurs me to look at these subjects at much greater depth. I think I understand your position on science and pseudoscience much better too. It is a topic that has concerned me of late, because I believe that confusion over the two has led us all into the trouble with this CAGW, a confusion that’ll cost us trillions. uncounted “units of misery” and actual lives before the madness goes away. Hoping to see you here and at your site; be well,
pk
Robert said @ur momisugly March 25, 2012 at 3:33 pm
Wrong. Check out the Wayback Machine. Barring the metaphorical plug being pulled, our words would appear to be preserved forever (or at least a very long time indeed). One can easily miss an Erratum, or Comment in a journal because it is necessarily in a later edition than the one you are reading.
Leif Svalgaard said @ur momisugly March 25, 2012 at 5:49 pm
There ya go! I always thought it was me he threw them at 🙂
The Pompous Git says:
March 25, 2012 at 1:19 pm
Pompous Git…funny, that moniker of yours. My wife who’s of a British extraction calls me that from time to time, especially when I adopt a lecturing tone on a topic, forgetting that it is she and my father-in-law who are the actual professors in our family. True, Galileo is often made into what he is not, but that’s the case it seems with most of the Renaissance giants, especially my favourite thinker of that crazy period, Niccolo Machievelli. It gets worse with Classical Greek philosophers, whose rather ordinary folk wisdoms that happened to be penned down were blown up out of proportion in the 19th century. Hoo boy, here I go again.
My issue with such examples, even where real persecution has occurred is simply that all they indicate is that establishments often act in stupid ways to the detriment of science, but that by virtue of doing so, they cannot in any way weaken or strengthen the substance of the persecuted position. Those strive or fall on their own merits or lack thereof.
The Pompous Git says: “Wrong. Check out the Wayback Machine. Barring the metaphorical plug being pulled, our words would appear to be preserved forever (or at least a very long time indeed). One can easily miss an Erratum, or Comment in a journal because it is necessarily in a later edition than the one you are reading.”
Sure, If one looks for it in such backup systems. But blogs, whether they are original or not, are not indexed in Google scholar or Microsoft Academic. Papers on the other hand, including Erratum, are indexed in Web of Science or Compendex, etc. There is a difference, maybe that difference is getting slightly smaller.
Willis Eschenbach says: “I first published on WUWT have subsequently appeared in peer-reviewed journals.”
This is precisely my point. I am almost sure they did not even referenced you in their publication, because they don’t have to – they are not obliged to look at every blogs. If that information was available in a journal database, as I mentioned above, you would have received proper recognition among that circles. But, having said that, I admire your effort. All the best.
tallbloke says:
March 25, 2012 at 2:18 pm
the 10.8 year component and the ~122 year harmonic are internal to the Sun, and these control the dynamo, and the 9.93 year and 11.86 year sideband frequencies arise as a necessary result of these fundamental periods. In other words, he proposes an identical model to Nicola Scafetta’s, but claims that the 9.93 year component and the 11.86 year component only happen to match the tidal period of Jupiter and Saturn and Jupiters orbital period by pure coincidence.
You have this a bit wrong. What I showed was that if we take the solar cycle period to be 10.810 year and if we assume a long cycle of 121.8944 years we reproduce the 9.91 and 11.87 years side-peaks. Now, the sunspot record is not long enough to determine any of these periods to two decimals [let alone one], and the long cycle is more like 104 years the past 3 centuries, so all of this is approximate only and there are no matches to 4 days accuracy (0.01 yr).
Furthermore I show that the coincidences only work if the tidal influence from Jupiter and Saturn are precisely equal which is unlikely as Saturn is smaller and further away. So, we are back to pure coincidence unless physical [and numerical] arguments can be made why the two influences should be equal.
Myrrh (March 25, 2012 at 5:03 pm):
There is a connection between between the study of Green and Armstrong’s study and mine. In their study Green and Armstrong (
http://www.forecastingprinciples.com/files/WarmAudit31.pdf ) use a different
terminology and methodology than mine ( http://judithcurry.com/2011/02/15/the-principles-of-reasoning-part-iii-logic-and-climatology/ ) but reach the same conclusion as I.They report (page 1006) that “…Trenberth (2007) and others have claimed that the IPCC does not provide forecasts but rather ‘scenarios’ or ‘projections’.” However, they report that “…the word ‘forecast’ and its
derivatives occurred 37 times and ‘predict’ and its derivatives occurred 90 times…” in Chapter 8 of the report of Working Group 1 in AR4. From these data, they conclude that the IPCC makes forecasts. To give them a name, I’ll call call them “IPCC forecasts.” Next, Green and Armstrong compare the methodology in the creation of the “IPCC forecasts” to criteria that are determinative of whether an “IPCC forecast” is a “scientific forecast.” On the basis of this comparison, they conclude that an “IPCC forecast” is not a “scientific forecast.”
Pertinent features of my study and of Green and Armstrong’s study become congruent when 1) my use of “projection” taken to be identical to that of Trenberth et al and the equivalent of of an “IPCC forecast” and 2) My use of “prediction” is taken to be the equivalent of Green and Armstrong’s use of “scientific forecast.” By separate routes, Green and Armstrong and I reach the identical conclusion that the methodology of the study that is described by Working Group 1 in AR4 was not “scientific.”
Terry Oldberg said @ur momisugly March 25, 2012 at 9:35 pm
Your words:
From the Routledge Encyclopedia of Philosophy:
So no, I didn’t jump; I was pushed 😉
Peter Kovachev said @ur momisugly March 25, 2012 at 6:27 pm
Nice thing about using it as a nom de plume is when someone calls me a pompous git. I just smile and say: “I know”.
Establishments often act in stupid ways to the detriment of everyone, not science alone. Barbara Tuchman’s The March of Folly: from Troy to Vietnam is a series of examples throughout history. Like all her books, it’s a gripping as a novel which seemed to upset some of my history lecturers who seemed to favour obscurantist writing.
Pompous:
In your most recent response you are winging it. It is time for me to bid you fairwell.
tallbloke says:
March 25, 2012 at 3:32 pm
Rog – There are a lot of coincidences in the universe. It’s just not enough. There has to be a causal mechanism to connect these things, and I just do not see one readily apparent. I’m as certain as I can be it isn’t gravity or the apparent motion of the Sun relative to the planets.
Whatever is causing the ~60 year cyclic or quasi-cyclic variation in the GATM, it is there. That is the major thing right now. Determining its origin may take decades of additional research. But, right now, it is readily apparent in the data. Within the next decade, it will become undeniable. And, that means that the anthropogenic impact on the climate, at least through release of long sequestered CO2, is negligible.
That’s my opinion, FWIW.
Bart says:
March 25, 2012 at 10:45 pm
Rog – There are a lot of coincidences in the universe. It’s just not enough.
And they usually fall by the wayside after some time. Here is another well-worn example that generated quite some excitement back then:
http://nldr.library.ucar.edu/collections/staffnotes/asset-000-000-000-565.pdf
Robert says:
March 25, 2012 at 7:46 pm
I’m sorry for my lack of clarity. What I meant was, I have first published things on WUWT, and then subsequently rewritten them. submitted them, and had them published in the peer-reviewed journals. So I got the benefits you mention. I regret the misunderstanding.
But suppose your scenario were the case. Suppose someone takes my idea and runs with it? Suppose I never get “proper recognition”? Let me pass on a lesson I was fortunate enough to learn early on.
I can accomplish almost anything if I don’t care who gets the credit.
So I have no problems if I see an idea of mine in the journals. Hey, it’d be great to get a hat tip or an attaboy, but I’m in it for the results, not the credit. Here’s a funny story about that.
When I was working in the Solomon Islands, a partner and I put together a proposal for a hydropower pre-feasibility study on one of the rivers. The country is broke and burns diesel for power, but they have wild uninhabited areas for run-of-the-river power plants. So I was pushing hydro, because I wanted to be involved in the project. I put together about a 25-page plan laying out the general parameters of the survey, the locations on the Tina River that warranted investigation, the landowner issues, the issues with the Solomon Islands Electrical Authority, the legal issues, the financial side, the whole thing.
We pitched it to World Bank and the Asian Development Bank, and both expressed interest in further discussions about providing funding.
Then we heard nothing for about three months.
Then one day I read in the paper that the World Bank is funding a pre-feasibility study on the Tina River … those World Bank cabrones had taken my plan lock, stock and barrel, the whole dang thing, and were promoting it as their own.
My partner and I had many a good laugh about that, because if we’d had to push the idea ourselves, it would have been a pile of work for both of us and taken forever, the World Bank bureaucracy is way slow when they want to. But since they stole the idea, the bureaucrats made sure it happened right away. Both my partner and I wanted it to happen for the good of the country, so we got our wish and even at double speed, because we didn’t get credit … and I got my plan implemented in the real world without lifting a finger. Go figure.
Finally, I’m an amateur scientist, which is an enviable position in that my advancement doesn’t depend on publication. The “publish or perish” system leads to a lot of bad papers. In fact, a flood of bad papers. So I can publish what I want to, when I want to.
And the best to you as well,
w.
Terry Oldberg said @ur momisugly March 25, 2012 at 10:40 pm
What an odd response!
Leif Svalgaard says:
March 25, 2012 at 5:14 pm
the 1.3 year thingy was a temporary fluke in messy data, and has gone away:
http://iopscience.iop.org/1742-6596/271/1/012075/pdf/1742-6596_271_1_012075.pdf
“After 15 years of GONG and MDI observations of the solar interior rotation, we
revisit the issue of variations in the rotation rate near the base of the convection zone. The
1.3-year period seen in the first few years of the observations disappeared after 2000 and has
still not returned”
Thanks Leif, I do appreciate your willingness to furnish us with data even while we are having a spat. 🙂
I note the following statement in the document.
“Even though the 1.3-year signal appears only in the early years of the data set, the variation
of the 0.72R equatorial rotation rate in MDI and GONG looks remarkably similar during
the whole period.”
So what does this mean? The 0.65R signal disppears (energy leaking meridionally), but the latitudianl signal at 0.75R remains? It’s so frustrating that we are left playing guessing games with short datasets. And that SC24 isn’t around the same strength as SC23. Oh well. Will the monitoring continue? I sure hope so.
Fig2 looks interesting, with sideband frequencies swelling and diminishing in different timeframes. Not a system we’d be able to understand without a much longer dataset. Concepts of a fairly simple mechanical dynamo being able to usefully describe the Sun’s electromagnetic behaviour properly are dead in the water for sure.
That’s why it’s a more useful approach to look at the solar system macro scale harmonic patterns (whatever the causative mechanism which undoubtedly links them), and try to model future solar behaviour from those. This is what Scafetta is attempting, and it is a reasonable and logical approach in my opinion.
TB: and can’t predict solar activity or hindcast it with any model dynamo
LS: Predicted cycle 24 quite nicely [and actually cycles 21, 22, and 23 too].
Using heuristics and observation just like the rest of us do, not with a coherent dynamo model which calculates anything from ‘first principles’.
Hindcasting you can always do by curve fitting.
True. We’ll only know if we got it right if the fitted model carries on performing well into the future.
Peter Kovachev says:
March 25, 2012 at 6:13 pm
My own areas of competence are in marketing, digital and traditional art and illustration
Peter, thanks for your response, and feel free to call by at my site, there is room there for art and literature as well as technical discussion, as the present thread demonstrates. My own degree is in History and Philosophy of science, but a lot of sciences used to involve the arts too, and I prefer an integrated and eclectic approach, as it stops things getting dull, and cross fertilises ideas in an interdisciplinary way. Something which is sorely needed in the stultified, institutionalised, compartmentalised and over-specialised faculty operations in our universities if they are going to make headway with the big puzzles the universe presents us with.
Lord Kelvin believed physics was pretty much sorted out, and that only the details were left to iron out. This led him to state categorically that “heavier than air flying machines are an impossibility”.
Similarly, I attended a lecture by the astronomer royale in 1988 where we were informed that the astrophysics was pretty much sorted out, and only the details were left to iron out. I nearly fell off my chair laughing, and got a dig in the ribs from the elbow of my phil of sci prof who later told me to be more respectful of the afflictions of others.
Willis Eschenbach said @ur momisugly March 25, 2012 at 11:05 pm
So you won’t mind if I pinch that statement for my epitaph; I’m more than happy to have it signed: “w.” 🙂
Bart says:
March 25, 2012 at 10:45 pm
tallbloke says:
March 25, 2012 at 3:32 pm
Rog – There are a lot of coincidences in the universe. It’s just not enough. There has to be a causal mechanism to connect these things, and I just do not see one readily apparent. I’m as certain as I can be it isn’t gravity or the apparent motion of the Sun relative to the planets.
You may be right. In which case we’ll need to have a rethink about the microstructure and macrostructure of space, because as I see it, there is no way the solar system can be stitched together the way it is, shot through with harmonics which persist in time, if there is no causal mechanism linking them. If it’s not gravity or electromagnetism via the void, then the void isn’t as void as we thought it was.
Whatever is causing the ~60 year cyclic or quasi-cyclic variation in the GATM, it is there. That is the major thing right now. Determining its origin may take decades of additional research. But, right now, it is readily apparent in the data. Within the next decade, it will become undeniable. And, that means that the anthropogenic impact on the climate, at least through release of long sequestered CO2, is negligible. That’s my opinion, FWIW.
The ~60 year cycle may persist, although not as strongly as in the late C19th and C20th, due to the destructive interference of other oceanic oscillations besided the PDO and AMO, and the now out of phase ~75 year Lunar and underlying 45 year solar system signature. As Willis says above, there’s lots going on, and it isn’t simple to untangle.
I still prefer to build as a celestial mechanic than be a stats monkey wrench in the works, though we all have a role to play. Checks on enthusiasm balance the overly-optimistic resistance against chaos. Some chaos is inevitable, but a large part of what is believed to be chaotic is the interaction of cycles we haven’t disentangled yet because we gave up and didn’t try hard enough.
I think Nicola Scafetta’s model will be vindicated in the long run, but it won’t be in our lifetimes, as we haven’t yet achieved the integrated understanding of the relative power of the various strong cyclicities well enough to predict at a timescale short enough to be of real value and interest to human society, which really needs decadal scale weather knowledge at regional resolution.
I still think we’re headed in the right direction though, and who knows, another breakthrough may be just around the corner.
Cheers
TB
I should add that the impending collapse in solar activity levels will give the impression that the ~60 year cycle is persisting strongly, but this will flatter believers in the solidity and overarching strength of that cycle to deceive them.
Simple it ain’t.
tallbloke says:
March 26, 2012 at 12:18 am
“Even though the 1.3-year signal appears only in the early years of the data set, the variation of the 0.72R equatorial rotation rate in MDI and GONG looks remarkably similar during
the whole period.” So what does this mean?
It just means that these [otherwise random] variations are not entirely due to instrumental noise.
Concepts of a fairly simple mechanical dynamo being able to usefully describe the Sun’s electromagnetic behaviour properly are dead in the water for sure.
That statement is nonsense. The dynamo models solve Maxwell’s electromagnetic equations as they apply to the plasma movements observed to take place in the sun.
This is what Scafetta is attempting, and it is a reasonable and logical approach in my opinion.
It is inferior to applying real physics.
LS: Predicted cycle 24 quite nicely [and actually cycles 21, 22, and 23 too].
Using heuristics and observation just like the rest of us do, not with a coherent dynamo model which calculates anything from ‘first principles’.
Again, you just don’t know your stuff. Here is how it is done: http://www.physics.iisc.ernet.in/~arnab/prl.pdf
tallbloke says:
March 26, 2012 at 1:00 am
I think Nicola Scafetta’s model will be vindicated in the long run, but it won’t be in our lifetimes, as we haven’t yet achieved the integrated understanding of the relative power of the various strong cyclicities
We need to understand the physics, not just the putative cycles. When the physics is hard. the theory needs to be guided by observations. Our theories of stellar evolution are checked by observations of millions of stars in all phases of their life. Similarly, our theories of the magnetic dynamo can be checked against the exemplars we observe of exoplanet systems. This is becoming more and more feasible as thousands of systems are becoming available to us with a wide range of relevant parameters [mass, rotation, magnetic field, age, composition, etc]. Already we are seeing results from this and in a few years time the question might be settled one way or the other, and the theories may be guided down the road to reliability. Reliable prediction [forecast, whatever…] of solar activity is becoming ever more important as our civilization relies more and more on space-borne assets. For this we need real science [physics, quantitative mathematical modeling], not ‘integrated understanding’ of pseudoscientific Keplerian cycles.