Solar Sigmoids Explained
Written by Nancy Atkinson
This figure shows the time evolution and final eruption of the sigmoid. Credit: NASA / STFC / ISAS / JAXA / A. Hood (St. Andrews), V. Archontis (St. Andrews)
S-shaped structures called 'Sigmoids' have been found in the outer atmosphere of the Sun — the corona. Sigmoids are thought to be a crucial part of explosive events like solar flares. Now a group of astronomers have developed the first model to reproduce and explain the nature of the different stages of a sigmoid’s life. Recently, the X-Ray Telescope (XRT) on board the Hinode space mission was used to obtain the first images of the formation and eruption phase of a sigmoid at high resolution. These observations revealed sigmoids have very complex structures.
Professor Alan Hood and Dr. Vasilis Archontis, both from the Mathematical Institute at St. Andrews University, Scotland, presented their team’s findings today at the European Week of Astronomy and Space Science conference at the University of Hertfordshire.
Over the years a series of theoretical and numerical models have been proposed to explain the nature of sigmoids but until now there was no explanation on how such complex structures form, erupt and fade away. The new model describes how sigmoids consist of many thin and twisted layers (or ribbons) of strong electric current. When these layers interact it leads to the formation of the observed powerful flares and the eruption of strong magnetic fields which carry highly energetic particles into interplanetary space. The team also found that as the sigmoids die out, they produce a 'flare' eruption.
Dr. Archontis sees the connection between the two astronomers’ model and work on predicting solar flares. He remarks, “Sigmoids work as 'mangers' or 'cocoons' for solar eruptions. There is a high probability that they will result in powerful eruptions and other explosive events. Our model helps scientists understand how this happens.”
Prof. Hood adds that these events have real significance for life on Earth, “Sigmoids are among the most interesting features for scientists trying to forecast the solar eruptions – events that can disrupt telecommunications, damage satellites and affect the way navigation systems are operated'.
Explanation of image: This figure shows the time evolution and final eruption of the sigmoid. It consists of three columns (time is running from top to bottom). Columns 1 and 2 show results from numerical experiments. The yellow isosurfaces are surfaces of electric current (left panels). Column 2 (middle panels) shows temperature. Column 3 shows 'temperature' (intensity) as it is recorded by the observations (Hinode mission). Notice that the agreement on the shape of the sigmoid, internal structure and thermal distribution along the sigmoid, between numerical experiments and observations is very good and fairly balanced. Notice, that even the 'flaring' episode (flashing) at the middle of the sigmoid at the down-right snapshot from observations is reproduced exceptionally well by our numerical experiments (down-middle). Credit: NASA / STFC / ISAS / JAXA / A. Hood (St. Andrews), V. Archontis (St. Andrews)
Source: RAS
Filed under: Solar Astronomy
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April 20th, 2009 at 3:03 pm
Come on Oils, I see the word "electric current" and "magnetic fields". Makes us laugh and give us your best shot!
I also am sure that you will find some reference from 1937 that EU has already modelled this perfectly and now we can compare the old EU models with the new model. Eughhh I mean that EU has a working model that can predict the bursts and shapes, not that EU predicted that there will be currents. Anyone can predict that there will be magnetich fields and currents out there that is easy but a working EU model from 1937? That would be cool!
April 20th, 2009 at 3:56 pm
You can mock me as much as you like, but we shall see who has the last laugh when the creationist occult dogma of gravitation is finally overturned and replaced with the truth of EU. The Great Theory of EU is fundamentally correct, and none of your so called 'evidence' of gravitation will ever persuade me to think otherwise. Now go back to your occult worship of your creationist God Newton and leave the real scientists to do their job.
April 20th, 2009 at 4:06 pm
Some idiot is posting as me, and while they are true, those are not my words.
April 20th, 2009 at 4:17 pm
Hell of a myth gravitation is! We put men on the moon, robots on Mars and a lander on Titan using gravity.
How did I guess OIM would post to this one!? This is indeed magnetohydrodynamics, but it does not overturn gravitation. Wound up magnetic fields beneath the photosphere burst forth and carry ionized gas with them.
These sigmoids look a bit like Julius sets.
Lawrence B. Crowell
April 20th, 2009 at 4:37 pm
Lawrence, you are completely wrong, it is very clearly electromagnetic, anybody with a modicum of intelligence will clearly see it. You have no idea what you are talking about. I am right, and that is all there is to it, so why would i believe somebody who still thinks of a 17th century creationist myth such as gravitation as 'scientific fact'.
These so called sigmoids clearly look like Julia sets, not Julius sets as you have incorrectly stated, which invalidates your entire post.
You 17th century occult creationists should get a clue. Read the quotes and take note of how correct the Great EU Theory is.
“It is therefore plausible, since the Earth moves the moon through its species and magnetic body, while the sun moves the planets similarly through an emitted species, that the sun is likewise a magnetic body.” — Johannes Kepler, astronomer/mathematician, 1609
“What we call mass would seem to be nothing but an appearance, and all inertia to be of electromagnetic origin.” — Henri Poincaré, physicist, 1908
“…to establish it [gravitation] as original or primitive in certain parts of matter is to resort either to miracle or an imaginary occult quality.” — Gottfreid W. Leibniz, polymath, July 1710
April 20th, 2009 at 5:40 pm
any time Oils joins a post it reminds me of Monty Python. "No one ever expects the Spanish Inquisition!"
Go ahead oils, blast gravity with your anti-ecclesiastic missile.
April 20th, 2009 at 5:57 pm
I must say that Kepler's opinion on the matter is a bit "old fashioned." There was another lesser known guy named Gilbert who wrote a treatise "De Magnete," where he too had some confusions on these matters. These confusions have largely been cleared up. Liebniz's objections stemmed from the matter that Newtonian gravity
F = GMm(r – r')/|r – r'|^3
implied these lines of force which were "mysterious." Of course the Coulomb rule for the electric force has exactly the same property!
My statement about Julius sets is just an compartive observation — nothing proven or invalidated.
Lawrence B. Crowell
April 20th, 2009 at 6:13 pm
What sort of God Newton believed in is not really relevant. Just explain what we see with a better model. Newton could worship electricity for all I care.
April 20th, 2009 at 6:27 pm
Newton was an occultist, and believing his theories is simply believing in the occult.
The better model is obviously EU theory, as anybody with intelligence can see is absolute truth. Your so called evidence against EU theory is fictitious, and stems from mainstream science's efforts to undermine the theory to advance creationist goals. It is a conspiracy against truth. It takes modern intelligent people such as myself to teach the world the error of their ways. Gravity is a myth born out of an evil occult conspiracy against people who believe in absolute truth , there is no such thing as gravitation, it is electromagnetic in origin. If anybody here says otherwise, then I out them as part of this evil global conspiracy.
April 20th, 2009 at 6:37 pm
Go Oils! Your powers of intelligence are only surpassed by your good looks and unwavering belief in conspiracy theories.
This is so funny….classic Oils at his best. HaHa!!
April 20th, 2009 at 6:59 pm
I am right, and you and all of your so called scientists and so called 'evidence' all are wrong. You cant prove me wrong. You will never beat me, for i am Right…we shall see who has the last laugh.
“First they ignore you, then they laugh at you, then they fight you, then you win.” – Mahatma Gandhi 1869-1948
April 20th, 2009 at 7:04 pm
OilIsMastery Says: The better model is obviously EU theory, as anybody with intelligence can see is absolute truth.
Yeah right, besides science is not about absolute truth. Anyone familiar with Hume or Popper is aware of the limitations of scientific knowledge. Science is not about finding any absolute truth, but more of a tentative variety of truth which holds in some domain of observation.
Newton lived in a time coming out of a period of religious upheaval. The English civil war, Cromwell's Commonwealth, and the restortation were a period where theological issues were "touchy," as well as in great flux. Newton devoted lots of time on the nature of the Trinity and Biblical numerology. It also has to be pointed out that Kepler was an astrologer and quite religious as well. It was a part of the age.
If you are concerned about an evil conspiracy against the truth, why don't you talk to Newt Gingrich. Right now he is convinced the Obama administration is conspiring to fix the census. Maybe you can get him going on this, which will serve to divert his attention away from policy. Even better it might make American people see what a nutcase he is.
Lawrence B. Crowell
April 20th, 2009 at 7:06 pm
Some idiot is posing as me, those are not my words, i said this earlier.
April 20th, 2009 at 7:20 pm
It is interesting that OilIsMastery #1 denies OilsMastery #2 posts usually within about 10 minutes after #1 posts them. This might be a case of split personality disorder! Yet both claim to have the same name. It sounds like a real psychic battle at work here!
L. C.
April 20th, 2009 at 7:39 pm
I get the feeling Oils suffers from at least three mental disorders. He is a complete and utter nutcase, and is as persistent as a smelly ( oily ) stain….Why does he even bother? Does he actually think hes convincing anybody here?
I think he does it for the lulz. Surely nobody can be THAT deluded…
April 20th, 2009 at 8:35 pm
I think he is either: a bright but misguided teen or a mentally disturbed adult…. hopefully the former. I suspect teen since there seems to be pervading lack of wisdom, little experience and a complete twisting of historical fact in his posts.
I also suspect that there are two individuals under the "oils" moniker. However, it would indeed be amazing if said persons inhabit a single body.
Either way, we are really responding to an internet troll. Thus I posit there is a 13-14 year old having fun at our expense.
April 20th, 2009 at 10:55 pm
So how long until we can make a weapon out of this phenomenon?
April 21st, 2009 at 12:07 am
I think it is pretty funny how he says, "those aren't my words! But, just so we're clear, I totally 100% agree with those words."
April 21st, 2009 at 12:32 am
Link to the paper:
http://www-solar.mcs.st-and.ac.uk/~vasilis/sigmoid.pdf
If electric currents actually do power the sun, the sigmoids and resulting flares are the result of some of the drift current being concentrated near the double layer above the photosphere, creating a number of short birkeland currents. When two of them are at a critical distance, the magnetic fields form a z-pinch between them. The sigmoid is a result of the electric current, between the birkeland filaments, feeding the pinch zone, being twisted between opposing polarities of the two charge sheaths that make up a double layer across the photosphere. Basically, horizontal magnetic shear. The shape comes from the 'right-hand rule', or the clockwise rotating magnetic field of the interacting birkeland filaments bending the secondary filaments created between them and the central pinch. When a plasmoid, with it's own charge density and magnetic field, is formed and ejected from the pinch zone, it can create axial beams, one electron beam towards the sun, one ion beam into interstellar space. The electron beam induces electron cooling into the pinch zone and the plasmoid itself, disrupting the current flow into the pinch and plasmoid, which causes the magnetic fields to collapse, which releases all of the energy/particles that had been contained within the fields…bam, solar flare/eruption.
A z-pinch with a twist, caused by the double layer.
April 21st, 2009 at 1:26 am
solrey said (first words);
"If electric currents actually do power the sun,"
They don't.
Therefore, then everything said after this is bull.
April 21st, 2009 at 2:21 am
Hey Oils…. Is this you???
http://tesladownunder.com/ModernThinker.htm
April 21st, 2009 at 3:44 am
Lets be sensible here. Gravity and magnetism have some properties superficially that are similar. Could it be that these are different emanations of the same power or force? Based on the fact that the more we discover, the more we discover what we do not know, then surely it would be logical to keep an open mind here. Remember the argument about whether light if molecular or wavular? I think also that we sould try to keep personal insults out of scientific discussion.
April 21st, 2009 at 5:12 am
Now now – despite my almost daily arguments with Oils and the fact that I believe he is mad and his arguments make no sense, I think he should be left to speak for himself… Posing as somebody else on a site such as this isn't cool.
It's happened to me before and it pissed me off real bad.
April 21st, 2009 at 7:22 am
@ solrey, Thanks for the link to the actual paper. After going through this 16 page paper twice, I could find no mention of Birkeland currents or z-pinch mechanisms. Could you please provide page numbers of this paper that directly mention either? Do you have a deep understanding of what this paper is about? It seems you're using the paper as a preface to insert your beliefs on EU as fact, when the paper makes no such claims. Here's an idea, why not write up your interpretation of these sigmoids and how they relate to EU, and submit them to a peer-reviewed journal? That would be the scientific route to take if you expect to be taken seriously by the professional astronomical & physics community. In previous posts, you've been asked to supply peer-reviewed, published papers that specifically lay out EU predictions of what the CMBR spectrum will look like from observations by the upcoming Planck mission, EU theory and HST-1 in M 87 and how EU models explain observations made of the galaxy cluster MACSJ0717. You have provided none. Now, you hold up this paper as confirmation of EU theory when the paper itself makes no such claims. Again, absence of evidence is evidence of absence. I would have to agree with sbc: "“If electric currents actually do power the sun,”
They don’t.
Therefore, then everything said after this is bull."
April 21st, 2009 at 7:56 am
Roger Levinson said:
When it comes to absolutely crazy notions of EU expressed here, science has been mostly thrown out the window. As too "the more we discover the more we don't know" is a bit of a negative misnomer. Actually, we are closer to the truth than we are to not knowing at all. Science is based on observation and evidence, followed by deduction by theory. Assumptions are not necessarily logical but they are mostly deduced from what we know. The scientific method sadly leaves no place for "an open mind."
As for the insults well they are just a part of life…
However, your own contentions are unfounded – in fact deliberately argumentative anyway. (Sounding like a EU'er to me, sorry.
April 21st, 2009 at 9:22 am
"Mostly deduced from what we know" Well, if you have only some of the facts then any scientific deduction cannot be fully regarded as accurate. Are we really closer to the "Truth" than otherwise? . Well that is also highly debatable. The scientific method demands an open mind since without it there is no imagination and without imagination we are denying one of our important and driving human traits. Finally insults are not part of life be merely a cover to hide an inability to logical express civilised thoughts. PS. I am a EU er, being a card carrying member of the European Union.
April 21st, 2009 at 9:39 am
From the paper:
"Later on (bottom row), XRT observed a brightening at
the middle part of the sigmoidal structure. McKenzie &
Canfield (2008) speculated that this brightening is the
sign of a cusped arcade that appeared after the eruption
of a long flux rope from the central part of the S structure. In our simulations, a considerable temperature and
density enhancment was also found around the central
sheet, between the two J-like bundle of fieldlines
."
The plasma physics/maths are the same, the primary difference is in the written description, so just substitute terminology:
Flux Rope = Birkeland current/axial jet from the central plasmoid
Cusped Arcade = the plasmoid formed within the z-pinch
Sigmoid (two J-like bundle of fieldlines) = two S-plasmoids
They also describe vertical "flux tubes" extending from and above the areas of greatest current density at the outer ends of the "sigmoid". That would describe the filaments, or Birkeland currents, that form where the drift current is locally dense enough to organize an enclosing, funnel shaped, sheath. A pinch zone forms when two of them come within a critical distance, based mostly on the size and strength of each filament. Biot-Savart law applies here, I believe.
@jon hanford
Where did I say that this paper proved EU theory or said anything about EU within? I linked the paper because, simply using a few different terms for the same things can provide a whole different perspective on what's taking place. It's merely what I consider corroborating evidence.
You don't accept the peer-reviewed papers I do provide so why should I waste my time chasing down more of them for you to blow off?
Thornhill was spot on in his predictions of what the results of the Deep Impact mission would be. The paper he submitted was not a formal, peer-reviewed sort…but he was right, none-the-less. So do his accurate predictions not count? Does the cumulative body of the science of plasma physics that's been researched for over a hundred years not count in the case of these 'sigmoids'?
@sbc
No, rl just sounded reasonable and open minded, that's why you thought he was an "EU'er".
April 21st, 2009 at 9:52 am
solrey said (first words);
“If electric currents actually do power the sun,”
If? If? You are not sure?
Actually the sun powers the electric currents, and this is NO IF!
April 21st, 2009 at 9:56 am
@ solrey:
Ah, you're here. There is another thread where there are many quastions waiting to be answerd. Would you be so kind?
@ Olaf:
Indeed.
April 21st, 2009 at 10:01 am
Roger Levinson Says:
"Lets be sensible here. Gravity and magnetism have some properties superficially that are similar. Could it be that these are different emanations of the same power or force?"
The answer is clearly NO!
Back then in 1937 you could have made this argument but in these modern time with colliders like the LHC there and all sxperiments that shows that the theory of relativity is acutally pretty accuratt, is no dicussion anymore about this that they are 2 different forces.
The inverse square law is applicable on anything that spreads in a sphere like manner, it could be gravity, it could an electric charge, but it can also be water droplets, light, paint.
Unless you believe that red paint spread in a sphere like sprinkler in would be proof that the EU is right since it happens to have the same inverse square formula as gravity does?
April 21st, 2009 at 10:13 am
@ Olaf and Roger Levinson:
Gravitation (Newton's law) and the electrostatic force (Coulomb's law) do, indeed, look similar. But the causes are different (mass and charge). Magnetism is different to both and does not have the same form (it is not created by charges (or some sort); it's due to motion of charges or the spin of charges. This has also some interesting consequences: If you transform into the system of rest of a charge the magnetic field disappears. You cannot perform this with gravitational or electrostatic fields.).
On the other hand: Physics tries to unify. For VERY high energies it has been performed for the electromagnetic, the weak and the strong force. All three of them belong to a "deeper force". This force has some symmetries that break at "too low" energies and then it splits up into the known three.
Since we lack a quantum theory of gravitation we have not been able to include gravity, yet. If we reach this point, we can unify all four fundamental forces and find that they belong to the same cause.
But again: This only holds for very high energies. You combine them all, you have to recreate the conditions of the Big Bang.
April 21st, 2009 at 10:14 am
Jon Hanford Says:
"@ solrey, Thanks for the link to the actual paper. After going through this 16 page paper twice, I could find no mention of Birkeland currents or z-pinch mechanisms."
I also do not see any mention that could describe from what I now know from the EU.
What is worse, they use real gravity AND magnetic reconnection, 2 things that is not allowed in the EU theory!
April 21st, 2009 at 10:15 am
Clearification:
All forces have probably the same cause – but that does not mean that they are the same (or behave alike).
April 21st, 2009 at 4:03 pm
I didn't write anything posted above. Idiots.
April 21st, 2009 at 4:04 pm
Salacious,
How old are you 4?
Stop impersonating me you moron.
April 21st, 2009 at 4:07 pm
Now, here is my response to the article.
The word Sigmoid was invented because they are ignorant of plasma.
Plasmoid is the correct word.
April 21st, 2009 at 4:36 pm
It is astounding that anyone would think that electric currents are a source of energy. The only electric currents which might qualify as such are excited electronic states in an atom. A source of energy obtains with some interaction which by quantum mechanics is able to set up bound states! A macroscopic current of electrical charge does not do that!
Lawrence B. Crowell
April 21st, 2009 at 4:37 pm
OilIsMastery Says: Plasmoid is the correct word.
In your case I think retardoid might be more accurate.
Lawrence B. Crowell
April 21st, 2009 at 6:44 pm
OilIsMastery said:
"Salacious,
How old are you 4?
Stop impersonating me you moron."
Paranoia set in eh?
I have not impersonated you at all. Why would I bother.
April 21st, 2009 at 8:05 pm
"It is astounding that anyone would think that electric currents are a source of energy. "
LOL.
April 21st, 2009 at 9:17 pm
I'm sure glad that I don't watch TV, if I did I wouldn't have time to read these posts, this is more fun. I don't understand much of what any of you are saying or talking about, but that doesn't seem to matter as i don't think any of you do either.
I love the comments the Oiils (?) mastery makes about how intelligent he is and has to educate the rest of us, reminds me of my neighbor in a Home Owners Association i used to live in, she knew far better than me how I should live and manage my life. Lots of those kind of people around. I sold that house and moved out of any HOA, me thinks Oiils should be ignored, but then where would the fun be? I would have to get TV
April 22nd, 2009 at 12:34 am
Angry Taxpayer,
I never said I was intelligent. That is a crackpot impersonating me in order to make you reject science in favor of pseudoscience.
April 22nd, 2009 at 5:25 am
RE: OilIsMastery and the alleged impostor.
Poe's Law states:
April 22nd, 2009 at 9:22 am
@ solrey, if you are going to link me to peer-reviewed papers, then start changing crucial wording to fit your theories, why not tell me of these substitutions in the same post with the link to the paper? Then you chastise me for not "knowing" : "The plasma physics/maths are the same, the primary difference is in the written description, so just substitute terminology:
Flux Rope = Birkeland current/axial jet from the central plasmoid
Cusped Arcade = the plasmoid formed within the z-pinch
Sigmoid (two J-like bundle of fieldlines) = two S-plasmoids" And why should I take your word for these 'definitions'. It's like saying "the sun is powered by fusion and gravity is the dominant force in the universe…..Oh, and by the way, for fusion, read electromagnetism and for gravity read plasma. Taking published papers and inserting your illogical terminology is not only confusing, it is deceptive and incorrect. So I won't be asking for peer-reviewed published papers from you since you're now prone to pick and choose which one of your favorite terms can be substituted for anything in the paper. It's no longer peer-reviewed after you've gone and changed parts of the accepted manuscript! And you still have not replied to Olaf's observation on this paper: "What is worse, they use real gravity AND magnetic reconnection, 2 things that is not allowed in the EU theory!"
April 23rd, 2009 at 9:25 am
@ Jon Hanford:
I agree with you, if solrey is going to cite a peer-reviewed paper and rely on substitution of terms, then he should notify readers in advance what those substitution of terms are.
(Then the readers know what to look for when reading — it helps solrey's ideas get across.)
But once solrey has so notified readers of the substitution of terms he is on solid ground scientifically.
Observation & measurement is one step in the scientific process — analysis & interpretation is another.
It is perfectly reasonable and respected to draw a different conclusion from a scientific paper based on a different interpretation of that scientific paper.
Clearly, electric current is present and a driving force at the surface of the Sun.
The questions which remains to be answered are thus: Is the energy at the surface of the Sun and above in the corona generated in an unobserved process inside the Sun, or is the energy transmitted to the Sun's surface and corona from an unobserved process outside the Sun?
Whether this energy is expressed as electromagnetic current s has been answered.
Yes, the Sun's energy is expressed as electromagnetic energy.
Oh and by the way, Jon Hanford, besides grousing about solrey's lack of notification of substitution of terms, you never did refute his analysis & interpretation of the paper he presented.
solrey's presentation was…well…Stellar!
Read the thread — notice who got the work done and presented analysis & interpretation of the post and paper and who spent all their time grousing about this and that.
solrey got the work done. His opponents were left to complain and grumble.
Congrats, solrey.
April 23rd, 2009 at 9:47 am
@ Jon Hanford:
Hanford states: "Taking published papers and inserting your illogical terminology is not only confusing, it is deceptive and incorrect."
As I stated, above, once you have announced your substitution of terms, and I will add, here, explanations for why the substitution is appropriate, then the analysis & interpretation is fine.
Jon Hanford, you must be unfamiliar with scientific process & practice for you not to know about the accepted practice of re-interpretation of observation & measurement in scientific papers.
But perhaps, "modern" astronomy is unused to this basic practice of modern science.
I got news for you — get used to it.
And some advice for astrophysicists — actively consider electromagnetism in both your observation & measurement and perhaps, more important, your analysis & interpretation — or expect to have somebody else do it for you.
First up gives you all the options.
Clean up gives you all the glory.
Solrey hit a grand slam home run.
And the authors of the paper?
Just men on base for the clean up batter.
April 23rd, 2009 at 2:47 pm
Anaconda said;
"solrey’s presentation was…well…Stellar!"
Solrey hit a grand slam home run."
What? Here we have the delusion jackass supports a half-blind fool. One "peer-reviewed paper" does mean the whole has of cards. Where is all the observation support? No where.
Get real, gravitation is the principle force driving most of the behaviour, only rare exotic phenomena is useful enough where electromagnetic is significant – and still it takes a gravitation source to drive it!
Dingbats rarely will be accepted if they have a pre-existing agenda. When they have been proven as deceptive and expressing falsehood, why should anyone believe you!
April 24th, 2009 at 6:48 am
Nancy and Fraser,
Don't know if it's doable however, some attempt at verifying the posters name with their Mail address may add to the integrity of this forum.
For instance (and this assumes you keep our Mail address on your data base and you verify that it is a valid address), I post as Will and my e-mail address is xxxx@gmail.com. Later on I submit another post as Wilma with my same e-mail address, your web s/w catches this and the later post added would read:
Wilma (aka Will) says:
April 23, 2009 at 2:45pm
My message………..
Something has to be done to eliminate the childish trash talk and impostor accusations and maybe get this forum back to respectability,