Hello! I'm a newbie and truly am no scientist. I have read this topic whole (and didn't undertand much of it) but some things made me curious.

1. Somewhere here someone mentioned that strong solar flares affect birds and insects. In what way? Is it about migration of birds and the way bees and ants move or something like that? Or is it more drastic than that?

2. Similar to the previous question: how come this does not affect humans? I thought that solar flares give you headaches, but someone mentioned that it's not because of magnetic stuff. So why is it so then? Is blood pressure affected? Or is it something entirely different.

3. Can modern navigation systems be affected? Imagine a scenario, in which there is an incredibly forceful geomagnetic storm (not sure of this is a correct term. I mean like one in XIX century). Can this storm break electronics, navigation, communication for good? Or just radio? We are talking imaginary-theoretically-possible-yet-unlikely scenario, mind you. Like what modern technology can withstand this?

4. Same scenario, but what about biological life. Carbon life. Like humans, animals, plants, mushrooms, all that. In a very strong storm/flare, can they be affected?

5. What can a person do in such case? Hide in an underground bunker? Leave for a place with a better situation geomagnetic-field-map-thing-wise? (I saw a map mentioned)? Or maybe there would be no person?

6. Can such flare possibly destroy communication and technology (and life?) on a whole side of earth, which is facing the Sun? Or maybe just a part that is the closest to the Sun?

Sorry if my questions are not scientific enough, I'm, again, no scientist. And I don't want to scaremonger, I just want to incorporate this theme into my art (I'm a writer). Also sorry in case I'm making no sense — I'm not a native English speaker.

8 hours ago, vityrady said:

2. Similar to the previous question: how come this does not affect humans? I thought that solar flares give you headaches, but someone mentioned that it's not because of magnetic stuff. So why is it so then? Is blood pressure affected? Or is it something entirely different.

I do not know about any research of impact of the flares on animals' behaviour, my brother-in-law claims that he gets migraines during geomagnetic storms (Hungary, so not many opportunities to test that). The flare itself should not be detectable, most of the SUV and x-rays should be absorbed by the atmosphere. The radiation ionises the upper atmosphere, but I do not see much of a possible impact on the animals. I could see something in the magnetic distortions, but those are usually up to few hundred nanoteslas... when the magnetic field is tens of microteslas, so quite a minuscule impact. Even if animals feel the magnetic field (pigeons with their magnetite beaks, or whatever they have), they would perceive it just as a small wiggling in the direction, I guess.

8 hours ago, vityrady said:

3. Can modern navigation systems be affected? Imagine a scenario, in which there is an incredibly forceful geomagnetic storm (not sure of this is a correct term. I mean like one in XIX century). Can this storm break electronics, navigation, communication for good? Or just radio? We are talking imaginary-theoretically-possible-yet-unlikely scenario, mind you. Like what modern technology can withstand this?

Strong changes in the magnetic field (up to few microteslas in some extreme cases) can lead to a large potential build-up in long electric networks and that could lead to some discharges and explosions in some more susceptible objects there. Small scale objects, like GPS receivers, should not be affected. They are, however, affected by the signal distortions due to plasma in the ionosphere, so you can have temporally imprecise navigation. No small-scale electronics would be affected seriously, but some long circuits could burn up if they are not prepared for that.

 

8 hours ago, vityrady said:

4. Same scenario, but what about biological life. Carbon life. Like humans, animals, plants, mushrooms, all that. In a very strong storm/flare, can they be affected?

Very strong flare could in theory shoot some proper dose of x-rays, but I am unsure, what is the practical limit for such a discharge, and if it has any potential to be not negligible. Strong proton storm maybe could penetrate down to Earth's surface leading to some cancer or what not.

8 hours ago, vityrady said:

5. What can a person do in such case? Hide in an underground bunker? Leave for a place with a better situation geomagnetic-field-map-thing-wise? (I saw a map mentioned)? Or maybe there would be no person?

In case of x-ray, the more wall you have between yourself and the source, the better. I do not think more than a typical roof would be needed even for the theoretically strongest possible flare.

 

9 hours ago, vityrady said:

6. Can such flare possibly destroy communication and technology (and life?) on a whole side of earth, which is facing the Sun? Or maybe just a part that is the closest to the Sun?

There were some discussions lately about an incredible possibility of X100+ flares from the sun... and those would have nearly no effect themselves. Another thing would be the possible CME and geomagnetic storm resulting from it. I am afraid I lack knowledge to estimate the strongest possible flare (we were jokingly talking about X500000 some time ago, but I doubt those are possible on our sun), so I do not know if there is any significant radiation risk on the surface. In case of the storm, big circuits can set stuff ablaze if they are not well protected. So far it does not seem that there could be anything apocalyptic for us. At worst we would have some serious trouble with lots of blackouts around the world, which would affect the economy and many people's comfort, but it would be far from the end of the world.

16 minutes ago, MJOdorczuk said:

I do not know about any research of impact of the flares on animals' behaviour, my brother-in-law claims that he gets migraines during geomagnetic storms (Hungary, so not many opportunities to test that). The flare itself should not be detectable, most of the SUV and x-rays should be absorbed by the atmosphere. The radiation ionises the upper atmosphere, but I do not see much of a possible impact on the animals. I could see something in the magnetic distortions, but those are usually up to few hundred nanoteslas... when the magnetic field is tens of microteslas, so quite a minuscule impact. Even if animals feel the magnetic field (pigeons with their magnetite beaks, or whatever they have), they would perceive it just as a small wiggling in the direction, I guess.

Strong changes in the magnetic field (up to few microteslas in some extreme cases) can lead to a large potential build-up in long electric networks and that could lead to some discharges and explosions in some more susceptible objects there. Small scale objects, like GPS receivers, should not be affected. They are, however, affected by the signal distortions due to plasma in the ionosphere, so you can have temporally imprecise navigation. No small-scale electronics would be affected seriously, but some long circuits could burn up if they are not prepared for that.

 

Very strong flare could in theory shoot some proper dose of x-rays, but I am unsure, what is the practical limit for such a discharge, and if it has any potential to be not negligible. Strong proton storm maybe could penetrate down to Earth's surface leading to some cancer or what not.

In case of x-ray, the more wall you have between yourself and the source, the better. I do not think more than a typical roof would be needed even for the theoretically strongest possible flare.

 

There were some discussions lately about an incredible possibility of X100+ flares from the sun... and those would have nearly no effect themselves. Another thing would be the possible CME and geomagnetic storm resulting from it. I am afraid I lack knowledge to estimate the strongest possible flare (we were jokingly talking about X500000 some time ago, but I doubt those are possible on our sun), so I do not know if there is any significant radiation risk on the surface. In case of the storm, big circuits can set stuff ablaze if they are not well protected. So far it does not seem that there could be anything apocalyptic for us. At worst we would have some serious trouble with lots of blackouts around the world, which would affect the economy and many people's comfort, but it would be far from the end of the world.

My own observation, and I'm still very new at this, is that CME has much more effect on technology than solar flares. I also used to think the flares were the biggest factor but just simple observation has shown me that they have strong transient effects, whereas the CMEs and geomagnetic storms are more powerful. They are also harder to track. It's what makes this whole topic so interesting - you can only figure out what the suns impact is while it is doing its thing, and it's impressive to witness... It's impossible to give guarantees. 

 

If solar activity worries you, you should probably ignore it, since you'll not be able to do anything about solar storms hitting us etc. They are totally out of our control. I'm comfortable with that. Some are worried by it. I think you could also worry about a gamma ray burst or roving black hole eating our planet - or a supervolcano going off - but what would that achieve? Nothing, it would only distract you from living.

 

Some things are out of our control. It's life.

Edited February 4Feb 4 by Stella

8 hours ago, Stella said:

If solar activity worries you, you should probably ignore it, since you'll not be able to do anything about solar storms hitting us etc. They are totally out of our control. I'm comfortable with that. Some are worried by it. I think you could also worry about a gamma ray burst or roving black hole eating our planet - or a supervolcano going off - but what would that achieve? Nothing, it would only distract you from living.

Thank you for your comment and your concern! But I do not worry about such things, I'm just a curious person in a search for a possible apocalypse to write about (I'm a writer, nothing serious though). I just figured that I should do as much research as I can in order not to spread harmful disinformation. This topic is rather interesting to me still. Thanks again!

And thank you @MJOdorczuk for answering my questions! You've made me realise, how deeply confused common folk as myself is! I'll look into it more.

34 minutes ago, vityrady said:

Thank you for your comment and your concern! But I do not worry about such things, I'm just a curious person in a search for a possible apocalypse to write about (I'm a writer, nothing serious though). I just figured that I should do as much research as I can in order not to spread harmful disinformation. This topic is rather interesting to me still. Thanks again!

And thank you @MJOdorczuk for answering my questions! You've made me realise, how deeply confused common folk as myself is! I'll look into it more.

One important confusion, I think here is, is the difference between a solar flare (which in some languages is confusingly called solar storm - looking at Norwegian here) and a geomagnetic storm. Solar flare is just a short event, where the magnetic field lines on the sun's surface "untangle" or reconnect and it produces huge energy outburst. Although we do not have anything comparable in scale here on Earth, but this "huge explosion" is barely visible among all the energy coming from the sun. The most important part of it is that the emissions are rather strong in EUV (extreme ultraviolet) and x-rays, and those are dangerous without any cover (like our atmosphere) and can ionise the air at about 100-500 km above the Earth's surface. It would be rather dangerous to whoever would be strolling around in the orbit without any protection, but those striders may have other problems in such a situation.

As the flares signify "untangling" of the magnetic field lines (AFAIK it is only a hypothetical model and we still lack understanding, what exactly is happening there), they can point to when big parts of the magnetic field detach and get ejected into space. We call them CMEs (coronal mass ejections). Such a blob holds quite strong magnetic field and can travel with incredible speeds (even over 3000 km/s, where a normal solar wind is 300-700 km/s). When it impacts Earth's magnetosphere, it can reconnect with it, injecting a lot of energy. It disturbs the currents inside, and may lead to formation of strong potentials in the ionosphere, which further lead to formation of strong currents. Those currents disturb Earth's magnetic field and cause electrons to accelerate down (and up at other places, ions to, but those we usually ignore due to small velocities) into the ionosphere, where they collide, sparking auroras. Note, that it is disturbance of the magnetosphere that causes all the currents, and all the plasma travels in a mostly closed loop around Earth, so there is no need for solar particles in the system... theoretically.

Now, when we talk about the currents being strongly enhanced; when they grow strong enough and start deflecting Earth's magnetic field enough, we observe it as Kp index rising, and when Kp >= 5 we call it a geomagnetic storm. All the currents are either outside of Earth, or high in the ionosphere (maybe coming down to 60 km or so, but really not lower), so there is no direct risk to us from them. However, strong current means strong magnetic field, and Earth's magnetic field of 20-60 microteslas can get deflected somewhere by even a few microteslas. Change in magnetic field induces currents, and currents cause a voltage rise over distance. The longer the distance, the higher the voltage. This means, very long (tens or even hundreds of km), well conducting circuits can end up with very high voltages, which can lead to arcs, temperature rises or even some explosions. That's what is worrying us in the strong geomagnetic storms.

If you want any other impact on animals, you mainly have either slight x-ray bursts, which I would consider negligible (though you can ramp them up in a fantasy tale) or magnetic disturbances, which on an animal scale (up to few meters) do not cause any significant currents, but may be detected by more susceptible creatures.

42 minutes ago, MJOdorczuk said:

One important confusion, I think here is, is the difference between a solar flare (which in some languages is confusingly called solar storm - looking at Norwegian here) and a geomagnetic storm. Solar flare is just a short event, where the magnetic field lines on the sun's surface "untangle" or reconnect and it produces huge energy outburst. Although we do not have anything comparable in scale here on Earth, but this "huge explosion" is barely visible among all the energy coming from the sun. The most important part of it is that the emissions are rather strong in EUV (extreme ultraviolet) and x-rays, and those are dangerous without any cover (like our atmosphere) and can ionise the air at about 100-500 km above the Earth's surface. It would be rather dangerous to whoever would be strolling around in the orbit without any protection, but those striders may have other problems in such a situation.

As the flares signify "untangling" of the magnetic field lines (AFAIK it is only a hypothetical model and we still lack understanding, what exactly is happening there), they can point to when big parts of the magnetic field detach and get ejected into space. We call them CMEs (coronal mass ejections). Such a blob holds quite strong magnetic field and can travel with incredible speeds (even over 3000 km/s, where a normal solar wind is 300-700 km/s). When it impacts Earth's magnetosphere, it can reconnect with it, injecting a lot of energy. It disturbs the currents inside, and may lead to formation of strong potentials in the ionosphere, which further lead to formation of strong currents. Those currents disturb Earth's magnetic field and cause electrons to accelerate down (and up at other places, ions to, but those we usually ignore due to small velocities) into the ionosphere, where they collide, sparking auroras. Note, that it is disturbance of the magnetosphere that causes all the currents, and all the plasma travels in a mostly closed loop around Earth, so there is no need for solar particles in the system... theoretically.

Now, when we talk about the currents being strongly enhanced; when they grow strong enough and start deflecting Earth's magnetic field enough, we observe it as Kp index rising, and when Kp >= 5 we call it a geomagnetic storm. All the currents are either outside of Earth, or high in the ionosphere (maybe coming down to 60 km or so, but really not lower), so there is no direct risk to us from them. However, strong current means strong magnetic field, and Earth's magnetic field of 20-60 microteslas can get deflected somewhere by even a few microteslas. Change in magnetic field induces currents, and currents cause a voltage rise over distance. The longer the distance, the higher the voltage. This means, very long (tens or even hundreds of km), well conducting circuits can end up with very high voltages, which can lead to arcs, temperature rises or even some explosions. That's what is worrying us in the strong geomagnetic storms.

If you want any other impact on animals, you mainly have either slight x-ray bursts, which I would consider negligible (though you can ramp them up in a fantasy tale) or magnetic disturbances, which on an animal scale (up to few meters) do not cause any significant currents, but may be detected by more susceptible creatures.

Thank you so much for breaking it down to simpler terms! I undertand better now. So, the greatest "threat" of all is a powerful CME? Which results in geomagnetic storm, correct?

Also, another stupid question, is there any effect from Aurora? Or Auroras just a result of solar activity? I mean, cause and effect, Aurora is an effect of solar activity, but can it also be a cause for something else concerning the Earth? Like can Auroras cause something? Sorry if it's too dense of me, I need to read more about physics (<_<)

 

30 minutes ago, vityrady said:

Thank you so much for breaking it down to simpler terms! I undertand better now. So, the greatest "threat" of all is a powerful CME? Which results in geomagnetic storm, correct?

Also, another stupid question, is there any effect from Aurora? Or Auroras just a result of solar activity? I mean, cause and effect, Aurora is an effect of solar activity, but can it also be a cause for something else concerning the Earth? Like can Auroras cause something? Sorry if it's too dense of me, I need to read more about physics (<_<)

 

Definitely auroras may lead to an increased risk of accidents because people get distracted more. Apart from that, they are just nice displays that light up the skies. They are a result of Birkeland currents coming out of Earth's surface (electrons flow against the current), leading to acceleration of electrons and their collision with the atmosphere at 80-400 km (in extreme cases maybe down to 60 km). Some emissions can reach near ultraviolet, but it is far from intensive, so I would not expect any harm from that. Maybe animals can also get disturbed by suddenly lit skies in the night.

On 2/5/2025 at 6:58 AM, vityrady said:

Thank you for your comment and your concern! But I do not worry about such things, I'm just a curious person in a search for a possible apocalypse to write about (I'm a writer, nothing serious though). I just figured that I should do as much research as I can in order not to spread harmful disinformation. This topic is rather interesting to me still. Thanks again!

And thank you @MJOdorczuk for answering my questions! You've made me realise, how deeply confused common folk as myself is! I'll look into it more.

Maybe look into the earth electrification hypothesis, since you'll be doing science fiction. How modern technology / pollution, combined with solar flares, might have disastrous consequences 

 

I don't think it's only hypothetical, some observations confirm it. it is novel, though, so it might be ideal for your story

Edited February 6Feb 6 by Stella

can someone help me? what is Night Light Film's app/website called for aurora chasing? He made one recently and I can't find it!!

is this a glitch? or is this real data? what can cause such a huge density spike?

4 hours ago, linkedwinters said:

is this a glitch? or is this real data? what can cause such a huge density spike?

It looks like alternating ACE and DSCOVER data.

Greetings,

When looking at the "Observations of Planetary K-Index" on the NOAA website, I notice that the higher values tend to be in the middle of the 3 hour increments timeline per day. I am curious why the observed k-index numbers are higher in the middle of the day. This is the noaa site that I am looking at: https://services.swpc.noaa.gov/text/daily-geomagnetic-indices.txt

When looking at the columns for High Latitude College - I notice the larger values are in the middle of the day. Perhaps the observed k-index is higher in the middle of the day (UTC time) and the aurora is stronger when night is near magnetic north. If anyone has input on this topic, I would like to hear some explanations. Thank you!

6 hours ago, Parabolic said:

It looks like alternating ACE and DSCOVER data.

Whose numbers are correct?

Edited February 17Feb 17 by Samrau

Is it possible for 2 coronal holes to combine into 1?

57 minutes ago, stargazer007 said:

Is it possible for 2 coronal holes to combine into 1?

yes

What is the cause of those short, low altitude pink auroras in high latitudes? They're my favourite kind, but I've been looking and I'm wondering if they're purely due to high solar winds and if there is no coronal hole you'll see less, if any of those. I ask, because there's not due to be a coronal hole during the week we're in tromso once more, so I'm worried about another low activity week

Right, satellites at L1 will not have eclipse time from the Earth, but what about Venus and Mercury?

Edited February 19Feb 19 by Zhe Yu

5 minutes ago, Zhe Yu said:

Right, satellites at L1 will not have eclipse time from the Earth, but what about Venus and Mercury?

Almost as much eclipse as we get. At worst these are just small specks on the solar shield... which actually made me curious now, if we have some nice SDO pictures with Venus/Mercury transiting.

1 minute ago, MJOdorczuk said:

Almost as much eclipse as we get. At worst these are just small specks on the solar shield... which actually made me curious now, if we have some nice SDO pictures with Venus/Mercury transiting.

I remember that time someone managed to get a photo of the sun transited by Mercury on a satellite. Very nice, it was!

5 hours ago, Zhe Yu said:

Right, satellites at L1 will not have eclipse time from the Earth, but what about Venus and Mercury?

Should in principle be possible, but L1 isn't so much closer that it'd look very different. Not sure how different the timings would be either due to the orbits around L1, but I don't think we have any imagery of transits from there at this point; then again, I don't think any of the satellites at L1 really do any direct imaging of the sun itself apart from coronagraphs (which block out the disk and thus prevent any view of transits), possibly because it doesn't really give us anything that can't be done just as well from orbits around Earth.

5 hours ago, MJOdorczuk said:

Almost as much eclipse as we get. At worst these are just small specks on the solar shield... which actually made me curious now, if we have some nice SDO pictures with Venus/Mercury transiting.

5 hours ago, Zhe Yu said:

I remember that time someone managed to get a photo of the sun transited by Mercury on a satellite. Very nice, it was!

Yeah, SDO captured the transit of Venus in 2012 and the transits of Mercury in 2016 and 2019. Here is the Venus one, and here and here are the Mercury ones. Hopefully SDO will still be operational for the next transit of Mercury in 2032, but I'm sure we'll get some satellite footage of it somehow in any case.

This was a question by the author in the book I am reading,

Underland by Robert Macfarlane:

----------------------------------------------------------------------------------------------

'Have you noticed,' says Helen M, 'how the stars show in greater number through the aurora?'

…But instead it has the counter-intuitive effect of causing more stars to show, clusters of them, which vanish back into the blackness when the aurora flickers away.  None of us can explain how the green light could be collaborative rather than competitive with the starlight.

-----------------------------------------------------------------------------------------------

He mentioned that the aurora was green.  My notion is that the green light made their eyes see more clearly, so the effect was not on the visibility of the stars, but the enhancement of their eyes.  If that is correct, there would not be any effect if the aurora was red instead of green.  I was hoping for knowledge or opinion from someone who has seen this effect!

Interesting! I know a physicist. Will ask them.

2 hours ago, Howard Krausse said:

This was a question by the author in the book I am reading,

Underland by Robert Macfarlane:

----------------------------------------------------------------------------------------------

'Have you noticed,' says Helen M, 'how the stars show in greater number through the aurora?'

…But instead it has the counter-intuitive effect of causing more stars to show, clusters of them, which vanish back into the blackness when the aurora flickers away.  None of us can explain how the green light could be collaborative rather than competitive with the starlight.

-----------------------------------------------------------------------------------------------

He mentioned that the aurora was green.  My notion is that the green light made their eyes see more clearly, so the effect was not on the visibility of the stars, but the enhancement of their eyes.  If that is correct, there would not be any effect if the aurora was red instead of green.  I was hoping for knowledge or opinion from someone who has seen this effect!

Interesting post , I think an additive filter effect is possibly the explanation. Ie because you are looking through luminate material , all instances behind also become extra luminate. Giving an accumalitive effect for those already enlightened entities in the background.

Or addition of auric light will have little effect upon the darkness of the background but will make barely visible stars increasingly brighter as the filter is in itself illuminate .

Edited February 19Feb 19 by Alphane

2 hours ago, Alphane said:

Interesting post , I think an additive filter effect is possibly the explanation. Ie because you are looking through luminate material , all instances behind also become extra luminate. Giving an accumalitive effect for those already enlightened entities in the background.

Or addition of auric light will have little effect upon the darkness of the background but will make barely visible stars increasingly brighter as the filter is in itself illuminate .

That doesn't sound like it make sense to me, given my knowledge of how light and vision works. I am not an ophthalmologist, but I have researched that topic some, and am also a physics student and learning about all manner of electromagnetic radiation.
I have personally found stars to be less visible behind aurora, both visually and photographically. The light from the aurora blots out and overwhelms the fainter ones, just like moonlight or light pollution or sunlight, and like how those can blot out aurora as well.
The aurora is no more than a natural source of light pollution in the sky, as far as seeing the stars is concerned, and it should not "amplify" the light from the stars, the same as city light pollution.

On 2/17/2025 at 10:20 AM, linkedwinters said:

What is the cause of those short, low altitude pink auroras in high latitudes? They're my favourite kind, but I've been looking and I'm wondering if they're purely due to high solar winds and if there is no coronal hole you'll see less, if any of those. I ask, because there's not due to be a coronal hole during the week we're in tromso once more, so I'm worried about another low activity week

That is the nitrogen fringe, caused by the high-energy particles that cause aurora penetrating further down into the atmosphere than normal, typically during heightened activity and at high latitudes. When they make it farther down into the atmosphere, they encounter nitrogen at pressures that are agreeable for it to fluoresce pink, quite different than the red and green oxygen above it, or nitrogen at other layers.
It's certainly a beautiful form of aurora, and one of the many advantages of the high latitudes. I have glimpsed it here in the midlatitudes during extreme storming, but never as clearly as they do up there, and certainly not as regularly.

Edited February 20Feb 20 by Sam Warfel

7 hours ago, Sam Warfel said:

I have personally found stars to be less visible behind aurora, both visually and photographically. The light from the aurora blots out and overwhelms the fainter ones, just like moonlight or light pollution or sunlight, and like how those can blot out aurora as well.
The aurora is no more than a natural source of light pollution in the sky, as far as seeing the stars is concerned, and it should not "amplify" the light from the stars, the same as city light pollution

I'm not as educated as you in the subject but was proposing a possible solution to the effect mentioned .

I imagine the aura as a fog being it's formed by stimulation of gas particles therefore looking through a fog of enlightened materials might effect the brightness of objects behind . Positively possibly .

Not sure wether the book mentioned is fiction and if the effect mentioned is actually truly observable in the real world . If so surely additive filtration is the explanation or at least I imagine so or would you propose some other possible explanation ? Or do you believe this is just a fictional scenario created by the writer ?

/Edit

After doing some searching I managed to find this image .

There doesn't appear to be more stars in the enlightened area but especially in the green area just left and below centre the stars certainly appear to be coloured by the aurora . Can also be seen more subtly in the pink areas. This effect is what I was trying to describe with my ' filter ' analogy . I would also agree with you though the brighter area of the aurora occlude the stars behind .

Edited February 20Feb 20 by Alphane
To add more evidence , add conclusion