Two types of solar flare, but only one prediction method.

[Michael Mozina]

It seems to me that the mainstream is only currently "predicting/forecasting one type of solar flare, the Z-pinch solar flare that most commonly occur near sunspots.

http://www.solarmonitor.org/forecast.php

There's actually a second type of "dark filament" flare that occurs that is not the result of an overloaded circuit, but rather than occurs as a result of a "dark filament" in the atmosphere becoming unstable and "lifting off" in the upper atmosphere where is more or less "explodes". To my knowledge the mainstream isn't even tracking the dark filaments seen in SDO images. Am I missing something? It seems to me that while the circuit overload types of flares that produce the most X-rays are dangerous, the most MASS that might hit Earth would be related to a dark filament eruption that was directed at us. I've actually seen dark filaments around sunspots become "bright" and erupt as well. IMO *THATS* probably what results in a Carrington class flare.

[Michael Mozina]

http://www.swpc.noaa.gov/ftpdir/plots/x ... 7_xray.gif
http://www.solarmonitor.org/region_pop. ... gion=11429

The first type of "circuit overload" type of flare and resulting CME is the kind we see today from region 11429. This type of flare is occurs when the plasma filament is overloaded to the point that the plasma simply "pinches" itself apart, resulting in the release of all the circuit energy at once. These types of flares typically result in large X-ray spikes and bursts, and large proton flux jumps within hours, sometimes less:

http://www.swpc.noaa.gov/ftpdir/plots/p ... proton.gif

I'll round up an example of a "dark filament" eruption, along with an x-ray and proton-flux charge to show the difference between the two types of CME.

[Michael Mozina]

The second type of coronal mass ejection is caused by a 'dark' filament eruption. IMO that can generate a far more DANGEROUS type of CME in terms of spewing a lot of material all at once. Unlike circuit overload types of flares, these mass ejections don't necessarily generate significant amounts of X-rays, but the mass contained in the thread is far greater in terms of the amount of material it can spew. Furthermore they can be located in and near active regions and be influenced by active region flares.

I uploaded a 22MG MP4 image of two dark filaments erupting on the 17th. Fortunately they spewed most of the material away from the Earth, but these types of flare pose the greatest threat in terms of their ability to spew charged particles at the Earth in great volume.

http://www.thesurfaceofthesun.com/filam ... uption.mp4

I'd seen similar events in SOHO images as far back as 2005, but with 1 megapixel resolution, and 10 minute cadence between images, it was tough to really see them as clearly as you can in SDO images.

Here's an example from my website of a dark filament eruption seen in SOHO:

http://www.thesurfaceofthesun.com/image ... it_195.mpg

I've started a categorization system that relates to the length, the proximity to active regions, and the movements of the thread, but so far I've had only relatively limited success in working out a system that gives me results I'm happy with. It seems like this type of potential CME should be predictable like active region flares based on sunspots, but the dark filament properties themselves have to be the determining factor in creating a useful filament eruption prediction system.

[hertz]

This is a very interesting hypothesis. I think I'd agree that the dark filaments are (much) more massive, which is perhaps why they're dark as opposed to in glow or arc mode (more mass takes more time to "get organized"?).

I suppose if something like that hit us "just right" it would be like sucker punching our magnetosphere. Wonder how much force it would take to: a)suffer a glancing blow, b)bring us to our knees c) knock us out. Must be alot though, and be fairly rare (like trying to hit a moving target while spinning around on a stool).

To me, the most interesting thing might be to see how they are related to the flares we're currently tracking. I'm guessing they are related; that is, the creation of surface flares is likely related to a process going on beneath them, which sometimes "gets out of hand".

As far as searching for them, how do you plan to backtrack to the source from the surface, aside from taking into account various rotational (both centrifugal and non-centrifugal (magnetic)), thermic/convective and perhaps other "false" forces that will allow us to put an "X" on a map? Sounds pretty cool, just a bit more than meteorological and definitely worth looking for to improve both our predictive powers and understanding of magnetic dynamos.

[Sparky]

Michael M, thanks for this info.... I found this gif on a site yesterday, but could not get it to function as a moving image..

I am not quite awake yet, so will have to come back to this thread and absorb what you are saying, but the dark mode plasma discharge is an area that needs to be investigated here on Earth more specifically and closely. thanks

[Michael Mozina]

This is a very interesting hypothesis. I think I'd agree that the dark filaments are (much) more massive, which is perhaps why they're dark as opposed to in glow or arc mode (more mass takes more time to "get organized"?).

I personally think the dark filaments are primary composed of carbon gas/dusty plasma, and serve a role that is similar to "clouds" in the Earth's atmosphere. They are current carrying threads like all dusty plasmas, but they are more dense. I've seen them form in and near active regions however and they tend to "heat up" pretty rapidly due to current flow changes in the filaments. There's a great SDO image of one of these dark filaments from spaceweather.com I'll try to find that shows the rotation of the Birkeland current filament, and the current flow changes that light up the material. When these form near active regions, and start carrying lots of current, I believe they pose the greatest potential for massive and powerful CME's.

I suppose if something like that hit us "just right" it would be like sucker punching our magnetosphere. Wonder how much force it would take to: a)suffer a glancing blow, b)bring us to our knees c) knock us out. Must be alot though, and be fairly rare (like trying to hit a moving target while spinning around on a stool).

We get hit with lots of plasma waves of all velocities on a regular basis but the Earth's EM shields hold up pretty well to the pounding. I think is more of a "density" issue that determines the actual damage it might do on the ground as a result of massive EM fluctuations.

To me, the most interesting thing might be to see how they are related to the flares we're currently tracking. I'm guessing they are related; that is, the creation of surface flares is likely related to a process going on beneath them, which sometimes "gets out of hand".

It's interesting you should mention that. I just attended a meeting at LMSAL on Tuesday on that topic that was put on by Christoph Kuckein. "Sometimes" (not always) the filament is oriented above a sunspot. In the particular example studied in the presentation I attended, the darker filament was oriented over a "developing" series of sunspots and penumbral filaments. Most of the time the sunspots were present. Much of the magnetic field flow energy energy however seemed to be concentrated "low" in the atmosphere, in the actual photosphere. It's not clear to me personally that the flow patterns and velocities that Christoph measured coming through the photosphere were directly related to or connected to the "dark filament' rather than "bright filaments" near the active regions, but I think the author believes they "can" and "do" interact. I'm sure they interact as well, but I think they're separate to start with. The flow velocities observed were 1.4-1.8 Km/S upwards, and 9.7 Km/S back into the photosphere in some cases and up to 1000-1100 Gauss in strength at max, typically more like 500-600 Gauss.

As far as searching for them, how do you plan to backtrack to the source from the surface, aside from taking into account various rotational (both centrifugal and non-centrifugal (magnetic)), thermic/convective and perhaps other "false" forces that will allow us to put an "X" on a map? Sounds pretty cool, just a bit more than meteorological and definitely worth looking for to improve both our predictive powers and understanding of magnetic dynamos.

The hard part for me isn't so much "tracking" them, as "predicting' their movements. "Sometimes" the thread becomes obviously unstable due to current flow changes through the filament (like the SDO image I'll post) and some or part of it "erupts". Other times (like in those videos) it's more like they reach a certain height and then "eventually" become unstable, as though they take an EM nudge from below, or based upon attraction to the heliosphere (above). It's not clear when those types of events might occur yet, at least not to me. I can 'sometimes' predict them correctly, but too often I'm inaccurate. I've figured out some categorization techniques, but I need more data to see if they provide me with any useful predictive value.

I'm the "dark filaments" erupt and work very differently than a typical 'coronal loop'. They're behaviors warrant a "prediction method" that isn't directly related to sunspot activity because they don't ALWAYS form (sometimes do) near sunspots, nor do they always erupt near them.

[Michael Mozina]

Michael M, thanks for this info.... I found this gif on a site yesterday, but could not get it to function as a moving image..

What kind of computer are you running? I'm on Windows 7 with the standard Windows player and it works just fine for me.

I am not quite awake yet, so will have to come back to this thread and absorb what you are saying, but the dark mode plasma discharge is an area that needs to be investigated here on Earth more specifically and closely. thanks

In this case I think the filament is dark because it's made of a more dense material and it's not carrying all that much current. I'll try to find that spaceweather video of the filament eruption I'm thinking about. It shows the intensity changes in the filament as the currents vary over time.

[Reality Check]

There is no physical difference between bright and dark filaments and so need for a prediction method that differentiates between them.
The difference between them is the contrast between the filament and their background. All dark filaments are bright when viewed on the edge of the Sun (prominences). Most bright filaments are dark when viewed against the body of the Sun, especially in the H-alpha line which is often used.
Note the absence of references to the scientific literature to support the assertion that there is a physical difference.

ETA: Dark filaments are useful because they can be easily automatically detected by image processing programs. Thus some of the solar fllare and CME prediction literature is based on analyses of dark filaments. Astronomers are also interested in CME that are heading for the Earth, i.e. ejected by flares on filaments that appear dark against the brighter Sun.

[Michael Mozina]

There is no physical difference between bright and dark filaments and so need for a prediction method that differentiates between them.

Wow RC, you needed a "fix" already eh?

I wholeheartedly disagree. They are different. Actually RC, there are clear differences between bright and dark filaments. For starters, bright filaments carry more current and emit high energy light, whereas the darker ones tend to ABSORB such light, and the currents that they carry don't tend to "heat them up" as quickly. In addition, the darker filaments tend to collect in the atmosphere and tend to 'concentrate mass' in ways that individual (brighter) filaments don't tend to do. More importantly, they aren't always near, nor do they erupt near "active regions" each time they erupt.

The difference between them is the contrast between the filament and their background. All dark filaments are bright when viewed on the edge of the Sun (prominences). Most bright filaments are dark when viewed against the body of the Sun, especially in the H-alpha line which is often used.
Note the absence of references to the scientific literature to support the assertion that there is a physical difference.

Sure, but some of the plasma filaments carry more current than others, and they may or may not be made of the same materials.

ETA: Dark filaments are useful because they can be easily automatically detected by image processing programs. Thus some of the solar fllare and CME prediction literature is based on analyses of dark filaments. Astronomers are also interested in CME that are heading for the Earth, i.e. ejected by flares on filaments that appear dark against the brighter Sun.

My point is that they aren't necessarily related to, or connected to active regions per se. They also 'erupt" like bright filaments, but in a different ways, for different reasons, and with the ability to spew a lot of mass. They don't necessarily experience a circuit overload condition the way X-ray filaments tend to do, which is why they don't always result in large amounts of x-rays, even though they can generate substantial sized CME's.

[Reality Check]

There is no physical difference between bright and dark filaments and so need for a prediction method that differentiates between them.

I wholeheartedly disagree. They are different. ...lots of unsupported assertions snipped...

Where are your citations to the scientific literature that state that dark filaments are different from bright filaments?

A demonstation that they are the same (a pretty picture so you will have to believe it!):
http://solar.physics.montana.edu/ypop/Program/hfilament.html

Prominences and filaments are really the same thing, but they look bright or dark depending on what is in the picture's background. At the right is another picture that shows a bunch of things. This is another H-alpha picture, and you can see the dark thread-like filaments on the Sun. You can also see some bright-looking prominences sticking out beyond the "edge" of the Sun on the far right. In the box, you can see one object that appears to be both filament and prominence! The part on the face of the Sun is dark (a filament) and the part hanging out past the edge is brighter than the empty space behind it (a prominence). You can see that it's all one piece, the only difference is how the object looks compared to what's behind it in the picture.

[Michael Mozina]

There is no physical difference between bright and dark filaments and so need for a prediction method that differentiates between them.

I wholeheartedly disagree. They are different. ...lots of unsupported assertions snipped...

Where are your citations to the scientific literature that state that dark filaments are different from bright filaments?

Your own citation was one! According to your link they are COOLER than the surrounding plasmas.

A demonstation that they are the same (a pretty picture so you will have to believe it!):
http://solar.physics.montana.edu/ypop/Program/hfilament.html

Prominences and filaments are really the same thing, but they look bright or dark depending on what is in the picture's background. At the right is another picture that shows a bunch of things. This is another H-alpha picture, and you can see the dark thread-like filaments on the Sun. You can also see some bright-looking prominences sticking out beyond the "edge" of the Sun on the far right. In the box, you can see one object that appears to be both filament and prominence! The part on the face of the Sun is dark (a filament) and the part hanging out past the edge is brighter than the empty space behind it (a prominence). You can see that it's all one piece, the only difference is how the object looks compared to what's behind it in the picture.

Well, you'll have to start by explaining why dark filaments absorb iron ion wavelengths (and many high energy wavelengths) for starters. How cool must hydrogen get to absorb everything from Halpha to 193A? Even in my way of thinking they COULD be composed of similar elements as bright filaments but the current flow THROUGH the filament and MASS of the filament is radically different between bright and dark filaments.

[Reality Check]

Your own citation was one! According to your link they are COOLER than the surrounding plasmas.

http://solar.physics.montana.edu/ypop/Program/hfilament.html
You do not understand the question. It is not what makes bright or dark filaments different from their surrounding plasmas.
The question is: What is the scientific evidence that you have for physical differences between bright and dark filaments.
Include citations to the scientific literature.

Well, you'll have to start by explaining why dark filaments absorb iron ion wavelengths (and many high energy wavelengths) for starters.

Well you will have to start by citing the papers that state that dark filaments absorb iron ion wavelengths (etc.) and bright filaments do not.
This should be quite easy - cite papers containing the absorption spectra from bright and dark filaments that you read to come to this conclusion.

I do hope that you are aware that these filaments are in images created from light emittedfrom various ions. They are only dark beacuse they are pictured against a brighter background.

[Michael Mozina]

Your own citation was one! According to your link they are COOLER than the surrounding plasmas.

http://solar.physics.montana.edu/ypop/Program/hfilament.html
You do not understand the question. It is not what makes bright or dark filaments different from their surrounding plasmas.
The question is: What is the scientific evidence that you have for physical differences between bright and dark filaments.
Include citations to the scientific literature.

You'll have to start by defining "physical differences". In own your reference, those "differences" amount to temperature variations. That's a given. The "bright" ones are necessarily composed of plasmas in excess of million degrees. The "dark ones" need not be, nor can they be radiating at those temperatures. The dark filaments ABSORB light in 193A, whereas the bright ones emit light in that same wavelength. The DIFFERENCE is related to the the flow of CURRENT and the heat produced in plasma PINCHES. Density also plays a role since individual bright filaments are typically "thin" structures, whereas dark filaments can be many hundreds of kilometers in size! There are obvious physical differences RC.

Well you will have to start by citing the papers that state that dark filaments absorb iron ion wavelengths (etc.) and bright filaments do not.

I did better than that. I showed you two of them in action. Go checkout the tornado thread too RC. It's all related.

This should be quite easy - cite papers containing the absorption spectra from bright and dark filaments that you read to come to this conclusion.

I think I'll start looking for such references in relationship to those tornadoes in the solar atmosphere. As they twirl on the horizon, they are dark against a bright horizon. Anyone WILLING to notice that, CAN notice that in any 193A or 171A image of a tornado in the solar atmosphere.

I do hope that you are aware that these filaments are in images created from light emittedfrom various ions. They are only dark beacuse they are pictured against a brighter background.

No. If they were emitting light too, those twister like dark filaments (tornadoes) would be BRIGHTER than the rest of the horizon. The material in the thread absorbs more light than it emits, therefore it's DARK and silhouetted against a brighter background.

Have you even accepted the fact that electrical discharges occur in flares RC?

[webolife]

My centropic pressure theory explains the dark and bright filaments way more simply. But rather than side track this thread with the details of that, consider these questions:
1. Would filamentous material being ejected from the sun be cooling with respect to the surface temperature?
2. Would filamentous material falling back toward the sun's surface be heating up?
3. SInce we primarily see dark filamentous material above sunspots and bright areas around the periphery of them, is it not reasonable to conclude that cooling/darkening as material moves away from the sun, and heating/brightening of material moving toward the sun is all the explanation necessary?

Be careful in analyzing solar flare data to observe what coloration technique is being employed in the photos. Has someone color coded the eruptions as bright or dark based on the light "frequency" being measured? Make sure brighter added colors are indices of hotter temperature.

[Reality Check]

You'll have to start by defining "physical differences". In own your reference, those "differences" amount to temperature variations.

My reference states that the physical difference between the filament and its background is temperature.
The bright filaments are necessarily composed of plasmas in excess of million degrees.
The dark filaments are necessarily composed of plasmas in excess of million degrees.
The physical difference that you need to find citations for are things like compostion and density.

I did better than that. I showed you two of them in action.

You did way worse than that - you asserted without evidence that dark filaments absorb light.
I have looked an many dark filaments and I see exactly the same situation as with sunspots - they are dark against a lighter background. Filaments emnit light (just look at them against space!). Sunspots emit light.

No. If they were emitting light too, those twister like dark filaments (tornadoes) would be BRIGHTER than the rest of the horizon

No. The filaments are hot plasma like the rest of the Sun. They are emitting light too. The horizon is emitting light too. It is the difference in birghtgness that makes the filamenst appear dark.

Have you even accepted the fact that electrical discharges occur in flares RC?

Have you even accepted the fact that electrical discharges are physically impossible in flares, MM?

For the benefit of lurkers:
MM stated the fantasy that "electrical discharges" cause flares in the JREF forum in November 2010. Since then he has ignored the physics that actual electrical discharges like lightning require the breakdown of a dielectric medium. Plasma is not a dielectric medium, it is highly conductive. See for example Anthony Peratt's definition of electrical discharge quoted there (http://forums.randi.org/showthread.php?postid=7660465#post7660465).
There is an obselete usage of the term in the 1960's by at least one author in the context of magnetic reconnection causing flares in a couple of papers. J.W. Dungey defines a large current density caused by magnetic reconnection as an "electrical discharge". MM liked to cite Dungey but did not realize that Dungey debunked MM's assertion.
Here MM just asserts that electrical discharges happen in flares. This is impossible.
But Dungey's "electrical discharges" do happen in the magnetic reconnection that Dungey states (and is the modern scientific theory) causes flares.

Micheael Mozina:
1. Cite the papers that state that dark filaments absorb iron ion wavelengths (etc.) and bright filaments do not.
2. Cite the papers that state that dark filaments bright filaments are physically different (density, composition, etc.).
Remeber that unsupported assertions based on "I see bunnes in the clouds" logic do not count unless I am mistaken about this forum. It is a forum about sceince, not personal fantasies?