Weak solar convection – approximately 100 times slower than scientists had previously projected

Fig. 1. Line-of-sight Doppler velocities are measured every 45 seconds at
4096  4096 pixels on the solar photosphere by the Helioseismic and Magnetic
Imager (background image). We cross correlate wave field records of temporal length T at points on opposing quadrants (blue with blue or red with red).

From New York University:  Researchers create ‘MRI’ of the sun’s interior motions

A team of scientists has created an “MRI” of the Sun’s interior plasma motions, shedding light on how it transfers heat from its deep interior to its surface. The result, which appears in the journal the Proceedings of the National Academy of Sciences, upends our understanding of how heat is transported outwards by the Sun and challenges existing explanations of the formation of sunspots and magnetic field generation.

The Sun’s heat, generated by nuclear fusion in its core, is transported to the surface by convection in the outer third. However, our understanding of this process is largely theoretical—the Sun is opaque, so convection cannot be directly observed. As a result, theories largely rest on what we know about fluid flow and then applying them to the Sun, which is primarily composed of hydrogen, helium, and plasma. 

Developing a more precise grasp of convection is vital to comprehending a range of phenomena, including the formation of sunspots, which have a lower temperature than the rest of the Sun’s surface, and the Sun’s magnetic field, which is created by its interior plasma motions.

In order to develop their “MRI” of the Sun’s plasma flows, the researchers examined high-resolution images of the Sun’s surface taken by the Helioseismic and Magnetic Imager (HMI) onboard NASA’s Solar Dynamics Observatory. Using a 16-million pixel camera, HMI measures motions on the Sun’s surface caused by convection.

Once the scientists captured the precise movement waves on the Sun’s surface, they were able to calculate its unseen plasma motions. This procedure is not unlike measuring the strength and direction of an ocean’s current by monitoring the time it takes a swimmer to move across the water—currents moving against the swimmer will result in slower times while those going in the same direction will produce faster times, with stronger and weaker currents enhancing or diminishing the impact on the swimmer.

What they found significantly departed from existing theory–specifically, the speed of the Sun’s plasma motions were approximately 100 times slower than scientists had previously projected.

“Our current theoretical understanding of magnetic field generation in the Sun relies on these motions being of a certain magnitude,” explained Shravan Hanasoge, an associate research scholar in geosciences at Princeton University and a visiting scholar at NYU’s Courant Institute of Mathematical Sciences. “These convective motions are currently believed to prop up large-scale circulations in the outer third of the Sun that generate magnetic fields.”

“However, our results suggest that convective motions in the Sun are nearly 100 times smaller than these current theoretical expectations,” continued Hanasoge, also a postdoctoral fellow at the Max Plank Institute in Katlenburg-Lindau, Germany. “If these motions are indeed that slow in the Sun, then the most widely accepted theory concerning the generation of solar magnetic field is broken, leaving us with no compelling theory to explain its generation of magnetic fields and the need to overhaul our understanding of the physics of the Sun’s interior.”

###

The study’s other co-authors were Thomas Duvall, an astrophysicist at NASA, and Katepalli Sreenivasan, University Professor in NYU’s Department of Physics and Courant Institute. Sreenivasan is also Senior Vice Provost for Science and Technology for the Global Network University at NYU and Provost of Polytechnic Institute of NYU.

===========================================================

ANOMALOUSLY WEAK SOLAR CONVECTION

Shravan M. Hanasoge  y and Thomas L. Duvall, Jr. z and Katepalli R. Sreenivasan

Convection in the solar interior is thought to comprise structures on a spectrum of scales. This conclusion emerges from phenomenological studies and numerical simulations, though neither covers the proper range of dynamical parameters of solar convection. Here, we analyze observations of the wavefield in the solar photosphere using techniques of time-distance helioseismology to image flows in the solar interior. We downsample and synthesize 900 billion wave-feld observations to produce 3 billion cross-correlations, which we average and fit, measuring 5 million wave travel times. Using these travel times, we deduce the underlying flow systems and study their statistics to bound convective velocity magnitudes in the solar interior, as a function of depth and spherical-harmonic degree l. Within the wavenumber band l < 60, Convective velocities are 20-100 times weaker than current theoretical estimates. This suggests the prevalence of a different paradigm of turbulence from that predicted by existing models, prompting the question: what mechanism transports the heat ux of a solar luminosity outwards? Advection is dominated by Coriolis forces for wavenumbers  l< 60, with Rossby numbers smaller than ~10-2 at r/Rθ= 0.96, suggesting that the Sun may be a much faster rotator than previously thought, and that large-scale convection may be quasi-geostrophic. The fact that iso-rotation contours in the Sun are not co-aligned with the axis of rotation suggests the presence of a latitudinal entropy gradient.

paper here: http://arxiv.org/pdf/1206.3173.pdf

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geo

Well now. That looks like the fox just achieved entry to the henhouse. Will the farmer knock him off expeditiously? Or will a bunch of new hens have to be acquired quickly?

David Schofield

Models 0
Observations 1

Wow! Exciting times for solar science.

Sceptical lefty

I suppose the ‘electric universe’ nutcases might have a coherent explanation, but nobody takes these deniers of conventional cosmology seriously. Best to stick with what we know (doesn’t work).

Almah Geddon

Our theory doesn’t match observation, therefore our theory is wrong. There is still real science being done.

Mike McMillan

“…using techniques of time-distance helioseismology to image ows in the solar interior…”
“Using these travel times, we deduce the underlying ow systems and study …”

These bolded words should be ‘flows’ and ‘flow.’
A pdf, will sometimes use a ligature character for ff, ffi, fl, and fi. Cutting and pasting won’t pick up these non-standard pdf characters.

steveta_uk

composed of hydrogen, helium, and plasma

In order to develop their “MRI” of the Sun’s plasma flows

I assume this means that the writers of the press releases think that science journos that are the target of the release are too technically incompetent to write their own dumbed-down versions for public consumption.

AndyG55

We fluids and water guys most often avoid turbulence areas in any calculation. Chaos rules in these areas. There is MUCH we don’t know. Butterfly wings etc….
How do you model and analyse chaotic system with accuracy…….. ya don’t !!
Stochastic and statistical analysis can help, but as you can see from the number of “suggests” in the above, any implied accuracy is a daydream.
Oh wait… the Earth’s atmosphere and climate is a chaotic system.. I guess the computer modellers know best.. LOL !!!

S Basinger

Queue Oliver K Manuel.

Gene

“The Sun’s heat, generated by nuclear fusion in its core, is transported to the surface by convection in the outer third. However, our understanding of this process is largely theoretical…”
Anthony, our understanding of the heat being generated by nuclear fusion in the core is also theoretical, and entirely so.

Julian Braggins

“Convective velocities are 20-100 times weaker than current theoretical estimates”
~~~~~~~~~~~~~~~~~~~~
Oops, back to the drawing board for basic assumptions? . EU anybody?

Paul Westhaver

Interesting article. I was reading it looking for evidence of insinuations of periodic behavior on the 11 year period scale. I believe the data is limited to a 27 day cycle (the period of the sun’s rotation). I didn’t see anything there, but the granularity is something.
… a couple of references to spherical harmonics but nothing that I could see that spoke to the 2022 anticipated near cessation of circulation activity. I wonder, there was a NASA guy in the paper but not sure if he was involved in the so the NASA prediction of the low flow of 2022 predicted in 2006.
http://science.nasa.gov/science-news/science-at-nasa/2006/10may_longrange/

RobertvdL

Is solar convection always so weak or do we have a ‘weak’ sun because of slower convection ?

Paul Westhaver

Just a thought.. and question…
Has there been any suggestion of a semisolid nugget or highly pressurized core in the sun? Something that acts like a slow moving stir stick, sort of a circulation memory that paces the slower cycles?

Brian H

Uh-oh! More encouragement for the “Iron Sun” and EU heretics. This study must be suppressed immediately. Else faith in the opening credo will be weakened: “The Sun’s heat, generated by nuclear fusion in its core, ….”

Fred

Interesting. So our base understanding of the fundamental principles which power our sun are incomplete or wrong, so I guess we can assume that counting on a nearly invariant sun in climate models is also wrong or incomplete.

If I understand correctly, this study is roughly equivalent to trying to figure out the large scale circulation of the Eath’s atmosphere , given detailed samples of radiation escaping at the top. Since the Sun’s atmosphere (“photosphere”) is opaque at all observing frequencies, this would be more like figuring out the circulation of Venus’ atmosphere.

Nerd

Sceptical lefty says:
July 9, 2012 at 1:07 am
I suppose the ‘electric universe’ nutcases might have a coherent explanation, but nobody takes these deniers of conventional cosmology seriously. Best to stick with what we know (doesn’t work).
===========
Lol. Might as well pay more attention to them. Liberal-complex academia is doing poorly these days… It’s hard to get anything going when they are in the way controlling everything from their Ivory Tower. We progress so slowly… That’s for sure.
Explain why we have sun scare but we depend on the sun for health? Why are they saying to avoid the sun to prevent skin cancer but we need the sun to cut down all kinds of cancer? 🙂

Gene says:
July 9, 2012 at 2:42 am
“The Sun’s heat, generated by nuclear fusion in its core, is transported to the surface by convection in the outer third. However, our understanding of this process is largely theoretical…”
Anthony, our understanding of the heat being generated by nuclear fusion in the core is also theoretical, and entirely so.

Anthony didn’t write that. He is posting a press release from New York University.
Readers constantly mistake quoted material for Anthony’s (and guest authors’) own words. Are there no formatting options in WordPress that will more clearly delineate quoted from original text? The simple Blockquote command (as above) should suffice, but large blocks of italics are daunting to some. Perhaps using indenting and a different Roman font would work, along with dividing borders.
/Mr Lynn

jlurtz

The first step on the way to a new theory is to discard the “words” that link your thoughts to the old theory. For example:
“The Sun’s heat, generated by nuclear fusion in its core, is transported to the surface by convection in the outer third. However, our understanding of this process is largely theoretical…”; the “words” ‘nuclear fusion in its core’ predispose one to the old theory.
The core is composed of 75% Helium [a waste product of Hydrogen fusion – Wiki]. Helium does not fuse at the lower temperatures and pressures that Hydrogen fuses. Helium fusion starts when gravity compresses the older star’s core after the Hydrogen is no longer available.
I would propose that Hydrogen fusion must take place on the surface of the core, and that the interior of the core is the waste dump for Helium. This would put the Hydrogen fusion at the inner edge of the radiative zone. In addition, the fusion locations would be highly non-uniformly distributed. This would produce hot locations and cooler locations producing convection just due to temperature, pressure differences.

Schitzree

Can i safely assume that, as this isn’t climate sience, the data and modles will be avalabe?

eyesonu

Will there be a circling of the wagons by the ‘old guard’ to destroy the careers of those who have observed something that hasn’t been observed or contradicts the theories of the current models and force the resignation of the editors of PNAS for publishing it?
Oh wait, that only happens in so-called ‘climate science’.

Nature has its reasons.
Some 30-40 years ago our own Dr. S (and his colleague) found out that the sun ‘has preferable’ longitude of activity, which drifts around very, very slowly. Joan Feynman referred to it as ‘magnetic memory’; I made an effort to depict it graphically from more recent data
http://www.vukcevic.talktalk.net/LFC7.htm
even our own earth is magnetically lumpy (to the east latitudes) http://www.vukcevic.talktalk.net/GMFd.gif possibly due to extra liquid at the east of the core http://phys.org/news191053615.html#nRlv
And surprise, surprise even the earth’s magnetic field oscillates, but fortunately for its inhabitants very weakly, barely noticeable.
http://www.jpl.nasa.gov/news/features.cfm?feature=2420
Solar science is fine but more investigation of our own planet is needed too.

jack morrow

So many theories are just that-theories. Dark energy,dark matter, sunspots, why the corona is hotter than the sun’s surface, lack of neutron density coming from the sun,black holes, the warped ring at the center of our galaxy,star formation, and on and on. Science always seems to have to be kicked and dragged before accepting new ideas. Sometimes this is best but it can also keep us from advancing as quickly as we could. Maybe it was meant to be.

Gene says:
July 9, 2012 at 2:42 am
Anthony, our understanding of the heat being generated by nuclear fusion in the core is also theoretical, and entirely so.
No. We observe just the neutrino flux we should based on fusion in the core. So there is direct observational evidence.
The issue of where the dynamo is located is important. With a shallow dynamo [ http://www.leif.org/research/Percolation%20and%20the%20Solar%20Dynamo.pdf ] there are fewer problems with slower convection.

son of mulder

I do hope we’re not trying to design fusion reactors based on physical constants derived from assuming the sun is a pure nuclear fusion reaction.

Steve Thatcher

This problem can be easily solved. Sack the astrophysicists, hire a few climatologists and with a handful of adjustments the existing theory will still be fine. No problem.
sarc off
Steve T

Nerd says:
July 9, 2012 at 4:47 am
Explain why we have sun scare but we depend on the sun for health? Why are they saying to avoid the sun to prevent skin cancer but we need the sun to cut down all kinds of cancer? 🙂
==============
Because false positives are widespread in science. The culprit is a subtle corruption of the scientific method that has gained widespread acceptance in the scientific community. Many scientists would strongly dispute they are breaking the scientific method, because the practice is widespread and “peer accepted”.
This has led to a rash of false positives throughout many fields that is self evident in large numbers of contradictory studies, all claiming to be correct.
The problem is that the scientific method requires that the methodology be independent of the data. If you feed back the result into your experimental design you greatly increase the odds of finding something significant to announce to the press (and your sponsors/employers) and you greatly increase the odds that the significance of these results is false.
However, the problem is so widespread that in many fields it is not even recognized as a problem. It is accepted science and routinely passes peer review. The consensus opinion is that that feedback is valid experimental design. So long as you call it something other than what it really is. Cherry picking with a new “scientific” name.

son of mulder says:
July 9, 2012 at 6:46 am
I do hope we’re not trying to design fusion reactors based on physical constants derived from assuming the sun is a pure nuclear fusion reaction.
It is actually the other way around: we use the accurately known physical ‘constants’ [reaction rates and cross sections] to derive that the sun is fueled by nuclear reactions. These reactions are directly observable via their emission of neutrinos with just the right flux calculated from the reactions.

Scientists wrong? Really?

jack mosevich

I am very disappointed in some of my fellow WUWT-ers for posting inane, snarky remarks about this research. What is the motivation for these digs? I bet these posters have never engaged in scientific research nor do they have much knowledge of science. Stop insulting people who are making honest attempts at furthering our understanding of a very complicated process. I have seen similar remarks in many WUWT threads and am embarrassed to read them.

Terry

Ah, the wonderous discovery of new things to keep us on our toes. Theories are sometimes best guesses waiting for observational verification. As the methods of observation are improved, so may the guesses be improved.

Wagathon

Reblogged this on evilincandescentbulb and commented:
This shakes us Earthlings to our core…literally. Whether or not we fully understand all of the reasons for it there is one thing about which reasonable people can all be certain: we know the independent variable that is the cause of global warming and cooling. Nominally, it’s the Sun, stupid.

Steven

Hmmm, maybe electric Birkeland currents since there is no known way to produce magnetic fields without electrical currents? Maybe when mainstream scientists actually figure out that the Sun is plasma and plasma is electrically charged, not nuclear, they may not be surprised so often. Take those blinders off people.
http://www.thunderbolts.info/tpod/2010/arch10/100519corona.htm
http://www.thunderbolts.info/tpod/2011/arch11/110105magnitude.htm
http://www.thunderbolts.info/tpod/2009/arch09/090707fusion.htm

ian cairns

True scientific research is observation, hypothesis, and hypothesis testing that tries to disprove the hypothesis .. then start the cycle again. Too many scientists are doing it wrong by trying to prove their hypothesis to be true, then building dogmas and non-working models that have to be propped up with more and more “tweaks”. If the observations disprove the hypothesis here, then the first step should be to confirm the observations by further research, or corollary research.
Ian

Leif Svalgaard says:
July 9, 2012 at 7:16 am
It is actually the other way around: we use the accurately known physical ‘constants’ [reaction rates and cross sections] to derive that the sun is fueled by nuclear reactions.
That said, there is a case where the existence of a physical nuclear property was made from the assumption of a stellar fusion process:
http://en.wikipedia.org/wiki/Triple-alpha_process
“Ordinarily, the probability of the triple alpha process would be extremely small. However, the beryllium-8 ground state has almost exactly the energy of two alpha particles. In the second step, 8Be + 4He has almost exactly the energy of an excited state of 12C. These resonances greatly increase the probability that an incoming alpha particle will combine with beryllium-8 to form carbon. The existence of this resonance was predicted by Fred Hoyle before its actual observation, based on the physical necessity for it to exist, in order for carbon to be formed in stars”

Davez

Has anyone ever tried to correlate the solar cycle with Jupiter’s perihelion date? They are the two largest bodies and certainly have some relationship.

Steven

If just one of you that believe magnetic forces can be created by any other means than electrical forces, please provide the paper???? Heat destroys magnets, so please do not try to tell me a permanent iron magnet is spinning at its core.
http://www.ehow.com/how-does_4926450_heat-affect-magnets.html
http://www.physlink.com/education/askexperts/ae472.cfm
http://www.newton.dep.anl.gov/askasci/phy99/phy99472.htm
You want the core to be hotter than the surface, yet the surface temperature would destroy a magnet in mili-seconds. So tell me, how does this magnetic field continually regenerate when electricity is the only known means of producing magnetic fields????? Could it be from ummm, electrical currents, the only known way to create magnetism? Nahhh, the couldn’t be it.

Steven says:
July 9, 2012 at 7:40 am
Hmmm, maybe electric Birkeland currents since there is no known way to produce magnetic fields without electrical currents?
How do you produce electric currents? Moving a conductor in a magnetic field, perhaps. That leads to the question: how do you produce the very first magnetic fields? The Biermann Battery Effect is the most promising answer: http://www.as.utexas.edu/~lindner/random/final.pdf

jayhd

Why are we wasting time and money studying the sun? Everyone knows its CO2, not the sun, that warms the earth. sarc off
Jay Davis

John F. Hultquist

The press release reports:
The result, . . . upends our understanding of . . . ~~ . . . our understanding of this process is largely theoretical . . .
Later:
. . .the most widely accepted theory concerning the generation of solar magnetic field is broken, leaving us with no compelling theory . . .
From these statements, it seems they were not sure what was going on before this study and they are now more sure that they do not know. How that “upends” anything is not clear.
~~~~~~~~~~~~~~~~~~~~~~~~~
Mr Lynn says:
July 9, 2012 at 5:11 am
RE: “Readers”

Alternatively they could learn to read.
~~~~~~~~~~~~~~~~~~~~~~~~
jack mosevich says:
July 9, 2012 at 7:22 am
RE: “disappointed”

People embarrass themselves. Others sometimes point it out. Often the latter are criticized by the former. In this instance, I agree with you. Still, my understanding of the subject has not been materially advanced by this press release. The comments are helping. Leif, others – Thanks.

Steven

Lief: Magnetic fields are created when particles in plasma (an electrically charged gas) move in opposition to one another and electric fields are created. The universe is 99.999% plasma, suggesting that learning how plasma behaves could be a good idea if you want to understand how the universe works. The theory you cite presupposes that the BB started it all. No evidence supports such finding, especially when you consider that plasma red-shift has now been directly observed in the laboratory. Of course being 99.999% plasma, it is inconceivable how the universe would behave in a plasma way, isn’t it?
http://vixra.org/pdf/1105.0010v1.pdf

Lancifer

Leif,
Thanks for the link to the Bierman Battery article. I had never thought about where magnetic fields had originated before. But wouldn’t a stream of electrons produce a magnetic field?
Also your answers to the many people with views opposed to the nuclear fusion model of stars are informative without being nasty or condescending. That’s the way scientific discussions should proceed.

Steven says:
July 9, 2012 at 8:52 am
Leif: Magnetic fields are created when particles in plasma (an electrically charged gas) move in opposition to one another and electric fields are created.
1: plasma is not electrically charged, but neutral. It consists of electrically charged particles, but so does all matter [think of an atom as a positively charged nucleus surrounded by negatively charged electrons]. What makes a plasma a plasma is that its temperature is so high that the electrons are torn away from the nuclei, so that we now have a mixture of negative charges and an equal amount of positive charges, but no longer bound to each other as in cold atoms.
2: how do you “move [the charges] in opposition to one another”. They oppositely charged particles attract each other, so some force must be applied to separate them. That is provided by a magnetic field. See e.g. here http://lpc1.clpccd.cc.ca.us/lpc/harpell/p4lec/Bfields/Bfields.html
So, magnetic fields are required to generate the current.

Lancifer says:
July 9, 2012 at 9:09 am
But wouldn’t a stream of electrons produce a magnetic field?
yes, but how do you produce a ‘stream of electrons’? It is done with a magnetic field that can separate positive and negative charges.

Pamela Gray

Leif, I seem to remember a comment of yours at least a couple years ago about you thinking convection was slower than thought and that you based your predictions on your slower convection calculations. If my recollection is close, well played Dr. S.

Steven

The same force is used to both attract and repell. It is called [electric] current and magnetism.
http://techtv.mit.edu/tags/441-physics/videos/813-mit-physics-demo—-forces-on-a-current-carrying-wire
It [does] both depending of if the Birkeland currents are moving the same direction or in opposite direction. No mysterious Dark matter or dark Energy is needed.http://wattsupwiththat.wordpress.com/wp-admin/edit-comments.php?comment_status=all#comments-form

Pamela Gray says:
July 9, 2012 at 9:17 am
Leif, I seem to remember a comment of yours at least a couple years ago about you thinking convection was slower than thought and that you based your predictions on your slower convection calculations.
Well, there is some confusion [brought about by a poorly worded press release – what else is new]. What the researchers found [BTW Tom Duvall is a colleague of mine, see e.g. http://www.leif.org/research/The%20Strength%20of%20the%20Sun's%20Polar%20Fields.pdf ] is that there seems to be fewer or slower ‘low-order’ movements [that is what is meant by the l < 60] than thought. These low-order things are large-scale: basically the “l” value says how large the waves are, how many will fit along the circumference. One such large-scale movement is the so-called ‘meridional circulation’ which plays a role in some dynamo models and it has been hard to find evidence for a deep-seated part of that circulation [its ‘return flow’]. A recent talk by David Hathaway has more on that: http://www.leif.org/EOS/20111212_NSO-Hathaway.pdf
These large-scale flows should not be called ‘convection’ per se. Convection is small-scale [and can be seen at the surface as granulation]. The issue in the research was to what extent large-scale organized flows exist.

Leif,
Good point. But isn’t it possible that Baryon asymmetry of the early universe, which is posited by some theories to explain the disparity between surviving matter and antimatter, could also provide a mechanism by which positive and negative charged particles could have been dispersed and produced magnetic fields?

Steven says:
July 9, 2012 at 9:29 am
It [does] both depending of if the Birkeland currents are moving the same direction or in opposite direction.
What makes the Birkeland currents move?