From NASA JPL: Solar flares – they’re big and they’re fast. They can knock out a satellite or create a beautiful aurora. And the jury is still out on what causes these explosions.
Flares, and the related coronal mass ejection, shoot energy, radiation, and magnetic fields out into space that can harm satellites or humans in space. Current observations aren’t precise enough to determine whether the eruptions are driven by energy surging through the sun’s surface, or by the sudden release of energy that has slowly accumulated in the atmosphere.
This aurora over Valkeakoski, Finland on September 15, 2000 resulted from the September 12 coronal mass ejection featured in the video above. › Download video Credit: Tom Eklund
Now, a new way of looking at old data has changed all that, but the results have created more mystery: There isn’t enough energy passing through the surface during the eruption to drive the explosion.
“In some sense, the idea that energy from below triggers the eruption is the easiest explanation – like a geyser,” says Peter Schuck, a physicist who studies space weather at NASA’s Goddard Space Flight Center in Greenbelt, Md. “But if the idea doesn’t agree with what’s observed, then it’s wrong. End of story.”
Schuck’s research indicates that, instead, the trigger occurs in the sun’s atmosphere. “Our result shows that observations are more consistent with a slow accumulation of energy in the atmosphere,” Schuck said, “and then a sudden explosion triggered from above, more like lightning.”
Schuck studies coronal mass ejections, or CMEs, and solar flares at the place where theory and observation overlap. His latest work on CMEs appeared in the Astrophysical Journal on May 1. Schuck constructed a way to test CME and flare observations in order to limit which group of hypotheses fit the data, even when there’s not enough evidence to conclusively pick a single theory.
In the case of CMEs, the data is limited to distant movies captured by spacecraft such as the Solar and Heliospheric Observatory (SOHO). These movies show that CMEs begin as a gigantic arch, some 50 times larger than Earth, with each of its feet planted on the sun’s surface, or “photosphere.”
Two broad camps of theories have been developed to explain these so-called coronal loops. “The energy is built up by either a twisting motion below the surface or the release of magnetic energy in the solar atmosphere,” says Haimin Wang, a physicist at the New Jersey Institute of Technology, whose work focuses on the characteristics of the photosphere before and during solar ejections.
Either way, the energy originally comes from the surface. The question is simply whether it surges through directly before the appearance of the coronal loop or oozes up slowly over time, storing up in the atmosphere until released in a massive explosion of light, plasma, magnetic fields and high energy particles.
Distinguishing between the two options based solely on a distant movie isn’t easy. Imagine trying to figure out what powers a car when all you’ve got to go on is a movie of a highway. Worse, that movie isn’t from above, so you might easily determine the direction and speed of those cars, but from head-on or a side view where you’re not even sure of the angle.
If, however, you can infer the speed of the car, you could at the very least figure out how much energy it has and, in turn, rule out any power source that didn’t jibe with what you saw.
Schuck has done exactly that. “I developed a way to infer magnetic field motion, and therefore energy amounts, from the velocities we observe in the photosphere,” he says.
Imagine the cars again. If the cars were coming directly toward you, you could measure the wavelength of the headlights and by determining how strongly they’d been shifted by the Doppler effect (that same wave-changing effect that causes sirens to sound higher as they come toward you and lower as they move away) you could measure the car’s speed.
Schuck used similar, head-on Doppler measurements to find the velocity of solar material on the surface of the sun. This material moves perpendicular to the magnetic field at the base of the coronal loop — the crux of what Schuck is trying to understand. He can convert those initial velocities of the sun’s surface into information about the motion and energy of the magnetic field. This analysis may not spit out an exact number for the energy, but it does give a precise, accurate range of energy possibilities.
And so, for the first time, one can look at images of the sun and set firm limits on the maximum energy at a given spot – at least if the material was moving directly towards the camera to provide an accurate Doppler measurement.
The next step applies the analysis to an actual coronal mass ejection. Schuck looked at the data from a CME on September 12, 2000. This was an M-class ejection — meaning it was fairly intense, but one step below the strongest X-class — that moved directly towards Earth. Conveniently, this was also a well-studied flare, so other scientists had already examined SOHO images to measure the path, speed, and energy of the CME. This information, in turn, implies how much energy would have come through the photosphere at the start of the process had it indeed initiated from below.
The results were dramatic. The SOHO images showed the photosphere moving at speeds 10,000 times less slowly than would have been expected if it were directly triggering the eruption. “The velocity you’d need to see on the photosphere would be a thousand kilometers per second,” says Shuck. “Not only are these speeds easily detected but they would be greater than the standard measurement range of the instrument. You’d see really weird stuff in the data readouts.”
There is always the slim chance that somehow the instruments didn’t catch the extreme motion, but given how large the velocities would have had to be, Schuck thinks this is unlikely.
This still leaves a variety of theories on just how the energy is stored and what triggers its release in the atmosphere. Distinguishing between those theories will require more detailed data—something scientists hope NASA’s Solar Dynamics Observatory, launched in February 2010 will be able to provide.
Unlike previous missions, SDO will be able to directly measure the energy in the photosphere – as opposed to Schuck’s present method of inferring that energy from velocity measurements — and it will do so with 20 times the resolution of the data on which Schuck based his current work. Such information will help narrow down what triggers a CME or solar flare even more precisely.
“Now we just need some really big CMEs to work with,” says Schuck.
h/t to Dr. Leif Svalgaard
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Leif Svalgaard says:
“That they require” betrays your anti-science attitude.
I’m not really sure that never observed hypothetical entities such as Inflation, Dark matter and Dark energy would qualify as science either Leif. All I am really saying is that I was a believer and now I’m a doubter. I’m not anti-science, if you could show me any evidence that any of these hypothetical entities actually exist beyond modeling and supposition then I would return to the fold. Occam’s razor when applied to the big bang theory and nuclear Sun comes up wanting. After 90 years following the big bang theory 96% of all predicted matter is missing or accounted for with these hypothetical entities.
Which one of us is really anti-science.
Phil
tallbloke says:
November 23, 2010 at 1:05 pm
The way I read it is they are saying it would have to be moving at 10,000km/sec to be the source of the explosion, but it moves 10,000 times more slowly, your 1km/sec.
The escape velocity is 627 km/sec so to blast off does not need 10,000 km/sec, only, say, 1000 km/sec.
So, if the energy is coming from below, it has to gradually build up in the atmosphere before it arcs it down to the solar surface (photosphere). What sort of energy is being gradually emitted from the photoshpere though? What form is it in?
Because of the large size of the coronal magnetic arcs anchored in the photosphere [and because of the high-enough electrical conductivity], the plasma is effectively ‘frozen’ or bound to the magnetic field. Normally when you twist a toy magnet in the air you can twist as long as you want, no magnetic energy is built up or stored in the surrounding air. But if the air [solar plasma in the corona] is conducting currents will be induced by the twisting magnet that will oppose the twisting. If you apply more force you can still twist the magnet but now the field lines [that before were free to slip and didn’t twist] would be twisted as well. A magnetic field stores energy given by the square of the field strength. Twisting the field increases the number of field lines per square meter. The field strength is just the number of field lines [the ‘flux’] per unit area, so twisting increases the field strength and thus the energy. As long as you keep twisting the energy [e.g. by moving the plasma at the feet of the arcs, e.g by rotating the sunspot] builds up and up and up. The electrical currents also increase and sooner or later the configuration becomes unstable, a ‘spark’ will fly and the explosion happens and the magnetic field reverts to its lowest energy state with the excess energy converted into heating, expansion, and ejection of the plasma [a CME].
Leif Svalgaard says:
November 23, 2010 at 1:23 pm
the magnetic field reverts to its lowest energy state with the excess energy converted into heating, expansion, and ejection of the plasma [a CME].
To complete the picture, the superheated gas in the corona travels down the field lines to heat the lower chromosphere and even photosphere giving rise to a sharp heating and brightening of those regions and we call it a ‘flare’. The heated lower atmosphere stuff often flows back up along the field lines and we see a set of ‘post-flare’ loops.
Really descriptive, thanks Leif. ISTR these arcs can be so big they loop up through ‘coronal holes’. Is it the high electric field around the arc which ‘punches holes in the corona’?
If the feet of the arc are located at adjacant sunspots, the spots would be of opposite sign wouldn’t they? So is the arc forming along a ‘field line’ between them?
Dr Svalgaard
GREAT POST !
THANK YOU !
Phil M2. says:
November 23, 2010 at 1:07 pm
if you could show me any evidence that any of these hypothetical entities actually exist beyond modeling and supposition
I think I have shown you already for the neutrinos which have been observed by multiple experiments. The Big Bang has lots of evidence too, but I can see that it will not make any difference to you [and if O/T for this thread – perhaps you could submit an article to WUWT explaining your problems with the BB and the matter can be discussed there]
tallbloke says:
November 23, 2010 at 1:57 pm
Really descriptive, thanks Leif. ISTR these arcs can be so big they loop up through ‘coronal holes’. Is it the high electric field around the arc which ‘punches holes in the corona’?
No [there is really no high electric field there – any such would quickly short out]. The coronal holes are simply caused by the lack of active regions within them with closed field lines to keep the corona at home. The polar areas are good examples. The solar wind is simply caused by the high temperature in the corona in combination with [somewhat counterintuitively] gravity [see deLaval nozzle http://en.wikipedia.org/wiki/De_Laval_nozzle ]
If the feet of the arc are located at adjacent sunspots, the spots would be of opposite sign wouldn’t they? So is the arc forming along a ‘field line’ between them?
Yes, that is what directly is observed.
vukcevic says:
November 23, 2010 at 1:59 pm
Dr Svalgaard GREAT POST !
Aren’t they all? 🙂
Leif Svalgaard says:
neutrinos which have been observed by multiple experiments
No they have not. Just the assumed effects have been observed. This charge-less almost mass-less particle has never been observed.
Lets call it a day Leif. I’m not doubting your skills in nuclear physics one iota. I just wonder why you are looking at the sun as a source.
Phil
Leif Svalgaard says:
November 23, 2010 at 1:23 pm
sooner or later the configuration becomes unstable, a ‘spark’ will fly and the explosion happens and the magnetic field reverts to its lowest energy state with the excess energy converted into heating, expansion, and ejection of the plasma [a CME].
There is a great movie of precisely that at http://www.spaceweather.com/
“STRESS RELIEF: The tension was just too great. On Nov. 21st around 1600 UT, a twisted filament of solar magnetism suddenly untwisted, producing a towering eruption off the sun’s northwestern limb. Click on the image to play a 6-hour time lapse movie from the Solar Dynamics Observatory:
http://www.spaceweather.com/swpod2010/22nov10/unwind_strip.jpg
http://www.spaceweather.com/swpod2010/22nov10/unwind512.gif?PHPSESSID=t6145fvftqe3bkljgm5ojndr60
http://www.spaceweather.com/
Phil M2. says:
November 23, 2010 at 3:06 pm
No they have not. Just the assumed effects have been observed. This charge-less almost mass-less particle has never been observed.
Has gravity been observed? I drop a heavy stone on my foot and it hurts. This is just the assumed effect?
I just wonder why you are looking at the sun as a source.
Because we can also measure the direction from where the neutrinos are observed, and that direction is from the Sun.
Leif Svalgaard says:
Has gravity been observed? I drop a heavy stone on my foot and it hurts. This is just the assumed effect?
If I place a strong magnet on top of a case and let a ball bearing loose, it will travel upwards. Is this anti-gravity or just an observed effect. Until everything else is ruled out it could be anything. I think comparing gravity to neutrinos is a bit of a push Leif.
“Because we can also measure the direction from where the neutrinos are observed, and that direction is from the Sun.”
And on earth, neutrino beams are also generated using nuclear fusion, no that’s not right, they use electromagnetic excitation of elementary subatomic particles…
Yes the sun is hot, yes it produces ‘something’ we call neutrinos but it does not require the nuclear sun to do this. On planet earth we use just plain old electricity. We see just what we want to see.
Phil
Electric fields don’t necessarily “short out” quickly when a sustained Electric Double Layer is present.
This post lends support to Hannnes Alfven’s hypothesis that CME’s are the result of an exploding double layer.
At any rate, in order to gain a better understanding of the physical dynamics of CME’s, observations & measurements must take into account all the physical perameters: Magetic fields, electric fields, charged particle density, location, direction and points of acceleration.
A model will never be an accurate reflection of the physical dynamics when it fails to take into account all the physical perameters present in the system where the “event” is happening.
From the post: “Now, a new way of looking at old data has changed all that, but the results have created more mystery: There isn’t enough energy passing through the surface during the eruption to drive the explosion.”
Seems to me, dismissal of alternative hypothesis, without scientific investigation, when the present model has failed is the hight of anti-science.
It’s not the souce of the ideas, but how well the ideas explain all the physical dynamics involved.
Phil M2. says:
November 23, 2010 at 4:20 pm
I think comparing gravity to neutrinos is a bit of a push Leif.
The issue is not the comparison, but the definition of an ‘observation’. Everything that we see, touch, feel, hear, etc are effects of something that we consider the cause of the effect. We observe a thunderclap by the effect it has on our ear and the electrical nerve impulses to our brain.
Yes the sun is hot, yes it produces ‘something’ we call neutrinos but it does not require the nuclear sun to do this. On planet earth we use just plain old electricity. We see just what we want to see.
No, we calculate from the fusion reaction rates what we should see and when we, in fact, do see what we calculate we are justified to claim that we understand what is going on.
James F. Evans says:
November 23, 2010 at 5:39 pm
Electric fields don’t necessarily “short out” quickly when a sustained Electric Double Layer is present.
What sustains the Double Layer?
Seems to me, dismissal of alternative hypothesis, without scientific investigation, when the present model has failed is the height of anti-science.
The paper did not take into account the alternative hypothesis because it is long discredited and nobody today lends any credence to it. And the ‘present model’ has not failed at all. Most solar scientists believe that the explosion is triggered from above. That is the current ‘dogma’.
“What sustains the Double Layer?”
The collision of moving bodies of plasma result in Electric Double Layers.
So, what sustains a Double Layer?
A consistent collision of moving plasma. Another way to think of it: The intersection where two streams of plasma meet.
“This still leaves a variety of theories on just how the energy is stored and what triggers its release in the atmosphere. Distinguishing between those theories will require more detailed data—something scientists hope NASA’s Solar Dynamics Observatory, launched in February 2010 will be able to provide.”
“Unlike previous missions, SDO will be able to directly measure the energy in the photosphere – as opposed to Schuck’s present method of inferring that energy from velocity measurements — and it will do so with 20 times the resolution of the data on which Schuck based his current work. Such information will help narrow down what triggers a CME or solar flare even more precisely.”
Anaconda: “At any rate, in order to gain a better understanding of the physical dynamics of CME’s, observations & measurements must take into account all the physical perameters: Magnetic fields, electric fields, charged particle density, location, direction and points of acceleration.”
I look forward to the results.
And, Alfven’s hypothesis of exploding double layers is still in the running.
James F. Evans says:
November 23, 2010 at 8:05 pm
A consistent collision of moving plasma. Another way to think of it: The intersection where two streams of plasma meet.
A double layer is a layer of charges of one sign next to a layer of charges of the opposite sign. A short is precisely when these two layers collide and neutralize each other. To maintain the double layer, the two layers must be prevented from colliding. In a high-conductivity plasma there is no process that does that.
And, Alfven’s hypothesis of exploding double layers is still in the running.
Not at all. Show us a recent link that explains CMEs by exploding double layers.
Leif Svalgaard and others
Thank you for your responses. I was not aware of the multiple types of neutrinos. Thank you for the links, I’ll have some reading to do. It will be facinating to see how this occilation was measured.
“In a high-conductivity plasma there is no process that does that.”
Oh, on the contrary, your favorite physical force seperates the two layers:
Magnetic fields.
Regarding Alfven’s hypothesis of exploding double layers:
The power of plasma physics is that laboratory experiments can quantify the process of exploding double layers in high resolution (which has already been done).
With the advent of the SDO, the formation of CME’s can be quantified in high resolution.
Then compare & contrast the physical dynamics of exploding double layers as observed & measured in the laboratory and the formation of CME’s as observed & measured in the solar environment.
Once CME’s are resolved, then the comparison between the two processes should be simple enough.
James F. Evans says:
November 23, 2010 at 9:27 pm
“In a high-conductivity plasma there is no process that does that.”
Oh, on the contrary, your favorite physical force seperates the two layers:
Magnetic fields.
Not on a sustained basis as you have to remove the magnetic fields to make the layers collide. You cannot have it both ways. What does happen is that when two neutral plasma regimes with oppositely directed magnetic fields are pressed together by movement of the plasma, the magnetic fields can reconnect which does generate an electric field [but no double layer] which can sustain a current, ultimately leading to the explosion. This is the modern paradigm as also demonstrated so clearly in the laboratory, e.g. http://mrx.pppl.gov/
“Not on a sustained basis as you have to remove the magnetic fields to make the layers collide.”
Of course, if there is no “short” then the magnetic fields are not removed and the double layer process continues unabated. On the other hand, if you want a “short” which releases large amounts of energy, i.e., explosion, as in an exploding double layer, then an increased amount of electromagnetic energy is introduced into the double layer process, which overcomes the “insulator” magnetic fields seperating the two layers.
Sorry, as discussed many times before, so-called “magnetic reconnection” is a failed paradigm. The proper paradigm is the one that takes into account all the physical forces, in this case all the electromagnetic forces: Magetic fields, electric fields, charged particle density, location, velocity, direction and points of acceleration.
The electric double layer model takes into account all of the above physical forces and particles, in contrast, the so-called “magnetic reconnection” model does not (although, recent in situ observation & measurement does take all of the above physical forces and particles into account and the results is to confirm the electric double layer process happens in space plasma environments as well as in laboratory plasma environments).
So, back to the simple process outlined in the above comment, but was ignored:
“The power of plasma physics is that laboratory experiments can quantify the process of exploding double layers in high resolution (which has already been done).
With the advent of the SDO, the formation of CME’s can be quantified in high resolution.
Then compare & contrast the physical dynamics of exploding double layers as observed & measured in the laboratory and the formation of CME’s as observed & measured in the solar environment.
Once CME’s are resolved, then the comparison between the two processes should be simple enough.”
James F. Evans says:
November 23, 2010 at 10:36 pm
then an increased amount of electromagnetic energy is introduced into the double layer process, which overcomes the “insulator” magnetic fields seperating the two layers.
Is gobbledygook. How do you introduce electromagnetic energy into a process?
Sorry, as discussed many times before, so-called “magnetic reconnection” is a failed paradigm.
You have, indeed, not benefited from the extensive discussion on this. The magnetic reconnection paradigm is the currently successful paradigm that underlies numerous experiments and spacecraft measurements. I gave you a link where you can learn more about this: http://mrx.pppl.gov/
Use it, and learn.
James F. Evans says:
November 23, 2010 at 10:36 pm
Sorry, as discussed many times before, so-called “magnetic reconnection” is a failed paradigm.
On the contrary it is very much alive and dominant and the basis for our understanding of much of the universe. A modern and thorough review of this fundamental, universal process can be found here: http://www.leif.org/EOS/yamada10rmp.pdf
Study it carefully.
Leif Svalgaard says:
November 23, 2010 at 11:14 pm
A modern and thorough review of this fundamental, universal process can be found here: http://www.leif.org/EOS/yamada10rmp.pdf
Study it carefully.
To help you getting started, here is the abstract:
“The fundamental physics of magnetic reconnection in laboratory and space plasmas is reviewed by discussing results from theory, numerical simulations, observations from space satellites, and recent results from laboratory plasma experiments. After a brief review of the well-known early work, representative recent experimental and theoretical works are discussed and the essence of significant modern findings are interpreted. In the area of local reconnection physics, many findings have been made with regard to two-fluid physics and are related to the cause of fast reconnection. Profiles of the neutral sheet, Hall currents, and the effects of guide field, collisions, and microturbulence are discussed to understand the fundamental processes in a local reconnection layer in both space and laboratory plasmas. While the understanding of the global reconnection dynamics is less developed, notable findings have been made on this issue through detailed documentation of magnetic self-organization phenomena in fusion plasmas. Application of magnetic reconnection physics to astrophysical plasmas is also discussed.”
There is no reference to Electric Double Layers, as is fitting in view of our modern understanding.
“There is no reference to Electric Double Layers, as is fitting in view of our modern understanding.”
Maybe it’s just modern terminology and you two aren’t as far apart as you seem to think? Magnetism and electricity are two sides of the same coin.
Dr. Svalgaard
Some time ago looked at Dst index (monthly) at kugi.kyoto website, but it appears that their website is defunct (http://swdcdb.kugi.kyoto-u.ac.jp/).
Your graph shows Dst index back to 1905, I would appreciate a link for the data download .
Thank you.
tallbloke says:
November 24, 2010 at 12:09 am
“There is no reference to Electric Double Layers, as is fitting in view of our modern understanding.”
Maybe it’s just modern terminology and you two aren’t as far apart as you seem to think? Magnetism and electricity are two sides of the same coin.
~
Yeah, exactly Tall Blokes
Electric double layers to some extent exist all over space and time to some degree, in various sizes and strengths.
Reconnection is also universal, as is gravitational forces and waves..
What happened got off the tracks..
Did the Moscow yes Moscow neutron monitor for 10.31.2000 to 10.31.2010 using 27 day resolution/corrected for pressure and appears we are back to 2007 levels, in terms of cosmic rays at Earth.
Wondering now about that 20% increase in our cosmic radiation belt now also reducing in its size or not.. just another layer..