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)

Solar Sigmoids Explained

20 Apr , 2009 by

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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


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Olaf
Member
Olaf
April 20, 2009 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!

OilIsMastery
Guest
April 20, 2009 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.

OilIsMastery
Guest
April 20, 2009 4:06 PM

Some idiot is posting as me, and while they are true, those are not my words.

Lawrence B. Crowell
Member
Lawrence B. Crowell
April 20, 2009 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

OilIsMastery
Guest
April 20, 2009 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… Read more »
Dominion
Member
April 20, 2009 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.

Lawrence B. Crowell
Member
Lawrence B. Crowell
April 20, 2009 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

Ryan
Guest
Ryan
April 20, 2009 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.

OilIsMastery
Guest
April 20, 2009 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… Read more »
GekkoNZ
Member
April 20, 2009 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!!

OilIsMastery
Guest
April 20, 2009 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

Lawrence B. Crowell
Member
Lawrence B. Crowell
April 20, 2009 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… Read more »
OilIsMastery
Guest
April 20, 2009 7:06 PM

Some idiot is posing as me, those are not my words, i said this earlier.

Lawrence B. Crowell
Member
Lawrence B. Crowell
April 20, 2009 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.

GekkoNZ
Member
April 20, 2009 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…

imode
Member
imode
April 20, 2009 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.

Morellio
Member
Morellio
April 20, 2009 10:55 PM

So how long until we can make a weapon out of this phenomenon?

Ryan
Guest
Ryan
April 21, 2009 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.”

solrey
Member
April 21, 2009 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… Read more »
Hon. Salacious B. Crumb
Guest
Hon. Salacious B. Crumb
April 21, 2009 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.

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