Are darker areas in 171 Angstrom "vacuous"?

[IDNeon]

I would like to propose (through a question for discussion) that dark areas in 171 Angstroms (and arguably 193 angstroms and some others) are not merely "colder patches" of gas; but vacuous. I wouldn't go so far as to say they are vacuums, but like the eye of a hurricane may be 10 or 30 millibars less pressure than the surrounding storm; these dark patches are less pressure areas; less plasma.

I have taken to watching videos, particularly 171 Angstroms at great lengths of time and have come up with some of my own terminology to explain things; but I won't dive deep into any wild theories, I simply want to discuss a more obvious and specific example.
 

Starting at 17:41 an event begins here:

The event becomes a field of solar-loops that by 17:45 becomes surrounded by a dark patch. It's pretty straightforward to watch.
I call the brighter areas "haze" because they look like haze. The darker areas to me appear to be more visibly clear, as if there is less material there, or "no haze".

I think in this event, if you see it for yourself, it appears that the beginning of a magnetic event absorbs material. But for whatever reason it absorbs material from further away than the local surrounding haze; as a result you see darkening take place sort of in the North-west direction.

Then, because now you have haze near the event, and darkening beyond it; that haze moves to fill the dark patch.

This movement looks like material being "blown away" from the eruption of the event; but actually I think it's just merely filling a void caused by the event drafting in a lot of matter from further away.

The end of the event results in a stable pressure configuration with only dark-clearer area around the solar-loops, and haze beyond it.

I have noted dozens of events where it makes sense to me that the dark areas in this wavelength aren't just colder, but also less dense or lower "pressure" if we were to think of it like terrestrial atmospherics.

There are, for example, solar tornadoes. If we think of them as terrestrial tornadoes the darker "interior" makes sense, it's an area of lower pressure, less material. The brighter "haze" that outlines these tornadoes is the "clouds"...or the hot condensing plasma as condensation is exothermic.

I am intrigued by this idea because I wonder if there's electrical properties to the vacuum vs. ionized plasma "haze"?

There are events that I will not directly point out in this opening post but that are like discharges shooting through the solar-wide dark patches. The speeds of which at the photopause (beginning of chromosphere end of photosphere where 171Angstroms should see) would be hypersonic. It's unreasonable (thought not impossible) to think that there are parcels of plasma discharging across these regions at hypersonic speeds; but if those areas were more vacuous then the speed of sound in those regions would be different. I wouldn't suppose what the speed of sound would actually be, but maybe these discharges would only be supersonic, or even subsonic.

I hope these discharges are hypersonic (which would mean the idea that the darker regions are more vacuous is maybe wrong) because I would love to get high resolution close-views of these discharges to see if we can make out any details we should see with hypersonic shockwaves.

As a devil's advocate; I've seen some incredible close-views of the solar poles in 171 Angstrom and the dark patches do not always look like "vacuous" areas, sometimes they look like dark clouds. But I'd like to distinguish that the dark areas I'm talking about are definitely the darkest; and most clear patches in the 171 Angstroms. A dark structure that has some light to it and looks like a dim-cloud (like a stormy day here) might very well be a colder patch of plasma. But not all such dark patches are thus.

[Parabolic]

When viewing in 171aia you're mostly looking at closed magnetic field lines, open magnetic field lines, and magnetic flux. I think what you're speaking of would be easier to examine in 193aia and 211aia.

There's no vacuousness in or on the solar surface; it's either colder, less dense plasma, or dense hot plasma. Even after an eruption, there is always material taking the place of whatever has been ejected. 

These localized areas with cold, less dense plasma also have more open-unipolar-magnetic fields. These areas are the main source of solar wind. When you see a localized dark area that persists, they are almost always Coronal Holes (not actually holes in the sun haha). Coronal Holes can appear at anytime but have also been known to form after eruptions. The winds they produce can range from 500km/s to 800km/s.

Other than that the rest of the solar surface that is featureless is just divided large magnetic field structures with one magnetic polarity.

[hamateur 1953]

41 minutes ago, Parabolic said:

When viewing in 171aia you're mostly looking at closed magnetic field lines, open magnetic field lines, and magnetic flux. I think what you're speaking of would be easier to examine in 193aia and 211aia.

There's no vacuousness in or on the solar surface; it's either colder, less dense plasma, or dense hot plasma. Even after an eruption, there is always material taking the place of whatever has been ejected. 

These localized areas with cold, less dense plasma also have more open-unipolar-magnetic fields. These areas are the main source of solar wind. When you see a localized dark area that persists, they are almost always Coronal Holes (not actually holes in the sun haha). Coronal Holes can appear at anytime but have also been known to form after eruptions. The winds they produce can range from 500km/s to 800km/s.

Other than that the rest of the solar surface that is featureless is just divided large magnetic field structures with one magnetic polarity.

Excellent reply!  Imho   I am always impressed at the knowledge I see displayed here. It helps me stay humble. 🤣

Edited March 18 by hamateur 1953

[IDNeon]

1 hour ago, Parabolic said:

When viewing in 171aia you're mostly looking at closed magnetic field lines, open magnetic field lines, and magnetic flux. I think what you're speaking of would be easier to examine in 193aia and 211aia.

There's no vacuousness in or on the solar surface; it's either colder, less dense plasma, or dense hot plasma. Even after an eruption, there is always material taking the place of whatever has been ejected. 

These localized areas with cold, less dense plasma also have more open-unipolar-magnetic fields. These areas are the main source of solar wind. When you see a localized dark area that persists, they are almost always Coronal Holes (not actually holes in the sun haha). Coronal Holes can appear at anytime but have also been known to form after eruptions. The winds they produce can range from 500km/s to 800km/s.

Other than that the rest of the solar surface that is featureless is just divided large magnetic field structures with one magnetic polarity.

If I may expand upon this; but in regular gas-law, colder would be MORE dense. But we seem to agree so naturally that the colder areas of the Sun are also less dense. I suppose from now on when I say "vacuous" I'll simply say less dense. But the density seems to drop to such an extreme that an area might be considered less "hazy".

Tangential question, then. In plasma physics is density and temperature correlated? The higher the temperature the more dense the plasma?

I read that higher temperatures leads to more kinetic energy leads to less density of particles, but this doesn't seem to make sense to me or is overly simplistic. In a field-constrained environment higher temperature can "cram" more particles into the same volume because of that energy, much how higher pressure in a bottle leads to both a more dense gas in the bottle and a hotter bottle.

So in that sense; perhaps I can imagine a correlation between density and coldness in the same way as autorefridgeration takes place when pressure drops from a container, in this case a magnetic-bottle?

To cut through my wordiness:

A cause, such as particles leaking to the solar wind, acts like gas leaking from a bottle. In this case a magnetic-bottle containing ionized-gas aka hot plasma. Similar to auto-refrigeration, due to the leak, the bottle loses density of that gas and loses temperature. Energy is escaping the bottle. In this case, we could say darker areas are losing dense-hot gas to the "hazy" areas on the chromosphere, or to the solar wind, etc?

Edited March 18 by IDNeon

[Parabolic]

When the plasma is still near the surface of the sun, temperature and density don't behave in the usual manner because of the extreme environment. However, when you observe the solar wind from a CH in space, it is much hotter and is less dense than the ambient solar wind around it. Especially when we compare ICME's to solar wind from a CH, the difference in temperature and density becomes very drastic. 

This plasma with frozen-in magnetic field escapes simply because of the difference in gas pressure throughout interplanetary space.

Once I have more time I'll link a few articles with details I possibly forgot to include.

Edited March 18 by Parabolic

[IDNeon]

12 minutes ago, Parabolic said:

When the plasma is still near the surface of the sun, temperature and density don't behave in the usual manner because of the extreme environment. However, when you observe the solar wind from a CH in space, it is much hotter and is less dense than the ambient solar wind around it. Especially when we compare ICME's to solar wind from a CH, the difference in temperature and density becomes very drastic. 

This plasma with frozen-in magnetic field escapes simply because of the difference in gas pressure throughout interplanetary space.

Once I have more time I'll link a few articles with details I possibly forgot to include.

Yeah that'd be cool; the "basic" searchable info is very hard to conceptualize. It took me a long time to realize that the "pressures" of .1ATM at the photosphere were for the surface only. And that the surface is like the top of Earth's Stratosphere. That by the bottom of the photosphere (300km deeper) the pressures rise dramatically?

So now I'm trying to conceptualize that "photopause"/chromosphere area. To me it still seems very much like a wispy atmosphere with "clouds" or hazes, etc.

I was hoping the magnetic bottle concept would be the most practical but from your description it looks like I have to consider the "darker" areas to be only an artifact of the sensor? After all we are not able to see it but have to sense it then artificially color it?

So the sensor is detecting only temperature at a specific wavelength? (In this case the 171?)

I still just want to conceptualize why it so much looks like clouds, haze and "clear holes"? As if a hazy atmosphere were too thin to cover the whole surface.

Then there's this really cool topography in the 171 Angstroms also? As if the darker areas are depressions (cold fronts) moving against warm fronts which are raised? Except in the area of the intense heating forming the solar loops?

[Parabolic]

2 hours ago, IDNeon said:

Yeah that'd be cool; the "basic" searchable info is very hard to conceptualize. It took me a long time to realize that the "pressures" of .1ATM at the photosphere were for the surface only. And that the surface is like the top of Earth's Stratosphere. That by the bottom of the photosphere (300km deeper) the pressures rise dramatically?

So now I'm trying to conceptualize that "photopause"/chromosphere area. To me it still seems very much like a wispy atmosphere with "clouds" or hazes, etc.

I was hoping the magnetic bottle concept would be the most practical but from your description it looks like I have to consider the "darker" areas to be only an artifact of the sensor? After all we are not able to see it but have to sense it then artificially color it?

So the sensor is detecting only temperature at a specific wavelength? (In this case the 171?)

I still just want to conceptualize why it so much looks like clouds, haze and "clear holes"? As if a hazy atmosphere were too thin to cover the whole surface.

Then there's this really cool topography in the 171 Angstroms also? As if the darker areas are depressions (cold fronts) moving against warm fronts which are raised? Except in the area of the intense heating forming the solar loops?

They are all images in different wavelengths of x-ray emissions. The darker patches are areas with nearly non existent x-ray emissions and brighter areas emit high energy x-ray emissions. Thus higher x-ray energy output = more heat and low energy x-ray emissions = less heat. What looks like clouds or haze is either the variations in X-ray emissions being influenced by magnetic flux, plasma rising and falling, or usually a combination of both. What you described as a cold front is more closely related to channels in the ocean, the one pictured in particular looks like a new filament channel.

These phenomena change so fast because of magnetic flux rising and breaching the surface, thus emitting x-ray light, then sinking and becoming dark again. When the magnetic flux is strong enough it can breach much more area on the solar surface and become a sunspot. This process is extremely exasperated during solar maximum as well. If compared solar max to solar minimum in 171aia you might a little surprised 🙂

 

[IDNeon]

1 hour ago, Parabolic said:

What you described as a cold front is more closely related to channels in the ocean, the one pictured in particular looks like a new filament channel.

Man, just keep dropping this deep knowledge, very useful and insightful. Something I like watching a lot are these mass-ejections that seem to come from a whole channel or carve out a whole channel.

Topographically they do look like troughs but I'm not sure if the topography is an illusion. I read about filament channels but if the filament channel is a "relatively cool and dense plasma suspended above the solar surface" then why do they appear as troughs surrounded by brighter, topographically higher, regions? Is that part an illusion caught in a moment?

I recall another video where these dark "troughs" could be though of as dark billowing clouds rather than absolute troughs.

PS - The whole area from the sunspot to the end of the green arrows appears to be "topographically lower" than the flat, higher, plateau to the upper right of the screenshot.

Edited March 18 by IDNeon
Fixed some grammar.

[Arthur brown]

Well, it's clear you've put a lot of thought into your observations, and that's commendable. However, one aspect that seems a bit off is your characterization of the dark areas as vacuous or less dense. In reality, those dark patches in the 171 Angstrom wavelength are not indicative of lower density or pressure; rather, they represent areas of cooler plasma. The brighter regions, on the other hand, indicate hotter plasma. So, instead of thinking of them as vacuous, it might be more accurate to view them as regions with different temperature gradients within the solar atmosphere.

Edited March 24 by Sam Warfel
formatting

[IDNeon]

On 3/24/2024 at 10:14 AM, Arthur brown said:

The brighter regions, on the other hand, indicate hotter plasma. So, instead of thinking of them as vacuous, it might be more accurate to view them as regions with different temperature gradients within the solar atmosphere.

Right; it would seem the areas I saw as "less dense" though are the filament channels which may or may not be "raised or lowered" in a topographical sense. The "haze" and cloudiness aspects of the 171 Angstroms (for example) is not consistent with brightness as you've noted.

I wonder though if there's a way to get a better sense of that topography; like cloud-levels above the surface of the photosphere? It would seem it would have to be constructed from a data set that isn't intended to display "altitude". Visually we can see them quite obviously, but I don't see any picture or set of data that does the work. Maybe something for Ai to tinker with...

The topography of these features interests me.