Given an X flare, probability of an associated CME?

[Drax Spacex]

My twin says that for X3 and higher flares, 100% of the time it will have an associated CME.  Obviously, this is wrong.  It/he/she/they also assert(s) that the higher the solar flare class, the more likely there will be an associated CME.  Does the data support this?

It would be interesting to know the answers to the following questions, though it may require extensive data review:

Given an M flare, what is the probability of an associated CME?

Given an X flare, what is the probability of an associated CME?

Given an X5 flare, what is the probability of an associated CME?

[MinYoongi]

Following since this is a good topic. i found this from a beloved twitter spaceweather human : 

 

 

[hamateur 1953]

47 minutes ago, Drax Spacex said:

My twin says that for X3 and higher flares, 100% of the time it will have an associated CME.  Obviously, this is wrong.  It/he/she/they also assert(s) that the higher the solar flare class, the more likely there will be an associated CME.  Does the data support this?

It would be interesting to know the answers to the following questions, though it may require extensive data review:

Given an M flare, what is the probability of an associated CME?

Given an X flare, what is the probability of an associated CME?

Given an X5 flare, what is the probability of an associated CME?

I’ve wondered the same, actually. It might be possible with our archives to assess this along with a parallel study of the GFZ index for a specific arrival if you really wanted to dig deep.  My gut feeling is that despite a high x ray level each x flare is unique in its terminal velocity hence the ability to spray stuff including protons out.  But I’m no physicist either.  Haha.    Edit. @tniickck was threatening violence against his own internet equipment if that X six failed to produce a CME. if my memory’s correct, I hope he was joking haha. 

Edited February 23 by hamateur 1953
Internet reference

[cheebee]

this is a good question i think

just from my perspective (and i could be wrong) it would depend on where in the suns layers the flare originated, if the explosion comes from deeper within the layers then it'll throw out ejecta but if it originates in the upper layers i guess it just hits us with the x ray and shockwaves the blast throughout the suns atmosphere

ive seen crazy cme's come from seemingly nothing whatsoever, and sneaky filament releases i feel are good examples, but also i've seen spots that are small with release silly amounts with hardly any flare at all

so although i feel there should be a potential link between flare intensity and cme release i've a feeling its overall very 'random' depending what actually happens during any given scenario tho it will probably lean towards the higher flare the more likely ejecta just cos it makes logical sense

i dont know how long youve been watching so i apologise if im just saying stuff you already observed yourself

[Justanerd]

2 hours ago, cheebee said:

this is a good question i think

just from my perspective (and i could be wrong) it would depend on where in the suns layers the flare originated, if the explosion comes from deeper within the layers then it'll throw out ejecta but if it originates in the upper layers i guess it just hits us with the x ray and shockwaves the blast throughout the suns atmosphere

ive seen crazy cme's come from seemingly nothing whatsoever, and sneaky filament releases i feel are good examples, but also i've seen spots that are small with release silly amounts with hardly any flare at all

so although i feel there should be a potential link between flare intensity and cme release i've a feeling its overall very 'random' depending what actually happens during any given scenario tho it will probably lean towards the higher flare the more likely ejecta just cos it makes logical sense

i dont know how long youve been watching so i apologise if im just saying stuff you already observed yourself

That’s exactly my theory - the deeper the origin, the more explosive the flare. Impulsive flares tend to come from near-surface, in my world anyway…

 

at least that’s how it works with my wife’s flares 😜😂

Edited February 24 by Justanerd
To be funny

[Vancanneyt Sander]

1 uur terug, Drax Spacex zei:

Given an M flare, what is the probability of an associated CME?

Given an X flare, what is the probability of an associated CME?

Given an X5 flare, what is the probability of an associated CME?

Strength only doesn’t equal CME. Duration is the key to CME. You can have a very very long duration C-flare that gives a very nice CME. Same with M-class long duration events and X-class long duration events.

so the question and answer is more:

1. what is the probability of a CME with an impulsive M/X class flare: very low (even if there is a CME it’s a narrow one)

2. what is the probability of a CME with a long duration C/M/X flare? 100%

43 minuten geleden, cheebee zei:

and sneaky filament releases i feel are good examples

Filaments have a lot of mass flowing along a magnetic field line. If that breaks, that mass is thrown partially into space and much will come down as coronal rain. These can generate bright big CMEs with low x-ray emission. Filament eruptions in x-ray is often a long duration event 😉 so CME likely. 

[Parabolic]

There is an actual sweet spot for solar flare intensity that simultaneously produces a noteworthy solar storm. The study is somewhat complex but it's easy to understand the gist of it. I'm going to over simplify the explanation a bit but I will post the link to the study.

Essentially, large complex active regions with intense magnetic fields end up caging in the solar storm. It is called 'magnetic caging'. 

https://iopscience.iop.org/article/10.3847/1538-4357/aba6ef

[Aten]

1 hour ago, Vancanneyt Sander said:

2. what is the probability of a CME with a long duration C/M/X flare? 100%

I'm not sure what the threshold is to be considered long duration, but I can remember a few flares that had quite long durations and no cme.

[Vancanneyt Sander]

6 uren geleden, Aten zei:

I'm not sure what the threshold is to be considered long duration, but I can remember a few flares that had quite long durations and no cme.

>1 hour

[libmar96]

I made a check a few days ago what was the strongest flare with no CME. I found only one candidate (on 1998/08/18), which was an X7.03 flare. It was very short and impulsive on graph, but followed a second M-flare minutes after which became a long duration one. It doesn't have any replay video attached on SWL to confirm, so to be checked. All stronger flares than the recent one have at least one condition matched: looks like a long duration on graph or contains a LASCO C3 replay on SWL (I don't have knowledge where to search for archive LASCO images).

[HalfFeralHuman]

It seems to me that CMEs usually, (or have to?) include magnetic reconfigurations in the outer corona to actually eject the contained plasma away from the sun. Those high-altitude corona reconfigurations might be the result of a chain reaction from more surface level field reconfigurations, but I magnetic reconfigurations in which field lines effectively snap open out to wider space for a time are the real driving force behind CMEs.

I've noticed that CMEs seem far more likely from flares where there's a lot of prior magnetic interplay between active regions, as can often be seen as plasma flows or correlative micro-flares, that kind of thing. When a region's interactions seem contained to mostly self-interaction the chances of a CME seem low.

This seems to tie in with the study @Parabolic put up, as it seems the larger and more energetic regions seem to tend to prefer interacting with themselves over other regions. Perhaps the fields need to be more condensed in order to be that energetic, or vice-versa?

Anyway, just some observations, interested if anyone else has seen similar trends.

[helios]

I think this question would also require a definition of what a CME is.

Often there is a faint shockwave leading to a weak CME, but not enough to cause a geomagnetic disturbance or even to be visible in LASCO.

So perhaps one with a flux rope?

An interesting paper in this regard is https://cdaw.gsfc.nasa.gov/publications/yashiro/yashiro2008IAU257.pdf

Edited February 24 by helios

[Philalethes]

13 hours ago, Parabolic said:

There is an actual sweet spot for solar flare intensity that simultaneously produces a noteworthy solar storm. The study is somewhat complex but it's easy to understand the gist of it. I'm going to over simplify the explanation a bit but I will post the link to the study.

Essentially, large complex active regions with intense magnetic fields end up caging in the solar storm. It is called 'magnetic caging'. 

https://iopscience.iop.org/article/10.3847/1538-4357/aba6ef

I don't think it says that there's a sweet spot for flare intensity, which would be rather unexpected, since we know that the most explosive events throughout history are associated with extremely strong flares. Generally you can see even in those graphs that flares of higher intensity tend to be more eruptive (the blue circles are higher up than the red ones on average).

It does certainly show that flux/area is highly relevant factor when it comes to eruptivity, just like duration is (as Sander mentions), but I believe Drax is asking about the chance of a flare of a given strength being associated with a CME if you disregard all other factors, just to see the statistical relationship between flare intensity and eruptivity.

As such I'd perhaps point to this paper, which investigates the general relationship between the two, as well as other relationships; they do indeed conclude that CME association rate increases with intensity, but also with fluence and duration, and these variables are naturally unlikely to be completely independent:

Quote

the CME association rate increases with flare’s peak flux, fluence, and duration

As illustrated:

That's certainly not to dismiss the flux/area relationship to eruptivity you're presenting, which would clearly also be yet another variable that would be wise to consider in terms of CME prediction based on the paper you're referencing.

A caveat to keep in mind is that the above is based on a specific sample, so percentages for the most intense flares might not necessarily reflect reality, which they indeed seem to not do here. For example, it seems to indicate that 100% of flares with a strength of ~X2 or more are associated with CMEs, which we obviously know isn't true. Looking at X-flares as a whole, they found that only ~10% of them were not associated with CMEs, presumably all around the X1-X2 range from looking at the graph.

It would also be interesting to see how these relationships differ from cycle to cycle, to see if there's e.g. any proof for this cycle having an abnormal amount of non-eruptive flares, or whether that's just bias, heh.

Edited February 24 by Philalethes
clarity

[Aten]

3 hours ago, libmar96 said:

I made a check a few days ago what was the strongest flare with no CME. I found only one candidate (on 1998/08/18), which was an X7.03 flare. It was very short and impulsive on graph, but followed a second M-flare minutes after which became a long duration one. It doesn't have any replay video attached on SWL to confirm, so to be checked. All stronger flares than the recent one have at least one condition matched: looks like a long duration on graph or contains a LASCO C3 replay on SWL (I don't have knowledge where to search for archive LASCO images).

You can view old LASCO images here: https://soho.nascom.nasa.gov/data/Theater/

Unfortunately there are no images for the X7 flare that you mentioned. In June 1998 contact was lost with SOHO and it took a few months to regain contact and start collecting data again.

[hamateur 1953]

This is probably the most interesting discussion I have viewed in my short time on this site.  Hopefully it gets archived, Mike 

[Parabolic]

2 hours ago, hamateur 1953 said:

This is probably the most interesting discussion I have viewed in my short time on this site.  Hopefully it gets archived, Mike 

It's extremely fascinating. Also, thank you @Philalethes your thoughtfulness for taking the time to help clarify and adding important information. 

[Drax Spacex]

Reviewing the archive for the top 35 flares, some discrete probabilities can be calculated for whether a CME is associated with a particular flare class.

For flares where a CME cannot be confirmed due to lack of coronograph imagery, I assume there is a CME if both Type II and Type IV radio sweeps are observed.   I assume there is not a CME if neither Type II nor Type IV radio sweep is observed.

Recognize these discrete probabilities are only for this data set.

For solar flare class X8 and higher, 100% have an associated CME.

For solar flare class X6.3-X7.79, 75% have an associated CME.

For solar flare class X5-X5.83, 78% have an associated CME.

Top 35 Rank,Flare class,CME in coronograph,Radio Burst Type II,Radio Burst Type IV
1,X40,Y,Y,Y
2,X28.57,Y,Y,Y
3,X24.5,Y,Y,Y
4,X24.42,Y,Y,Y
5,X20.67,Y,Y,Y
6,X14.36,Y,Y,Y
7,X13.37,Y,Y,Y
8,X12.97,Y,N,Y
9,X12.95,?,Y,Y
10,X11.96,Y,Y,Y
11,X11.88,Y,Y,Y
12,X10.18,Y,Y,Y
13,X9.96,Y,Y,Y
14,X9.4,?,Y,Y
15,X8.9,Y,Y,Y
16,X8.87,?,Y,Y
17,X8.21,Y,Y,Y
18,X8.08,Y,N,N
19,X7.79,Y,Y,Y
20,X7.77,?,N,Y
21,X7.77,Y,Y,N
22,X7.7,Y,Y,Y
23,X7.13,Y,Y,Y
24,X7.03,?,Y,Y
25,X6.98,Y,Y,Y
26,X6.3,N,N,N
27,X5.83,Y,Y,N
28,X5.61,Y,Y,Y
29,X5.57,?,Y,Y
30,X5.52,Y,Y,Y
31,X5.37,?,Y,Y
32,X5.24,N,Y,N
33,X5.17,?,N,N
34,X5.17,Y,Y,Y
35,X5,Y,N,Y

Edited February 25 by Drax Spacex