Steady S2 Rad Storm

[Christopher Shriver]

I am calling for others to remark on past observations which looked like this.

The "smoothness" of this proton event is remarkable, as it hardly aligns with any adjacent activity. This either suggests the large CME we observed recently in a partial halo had a lot of energy, or other dynamics are unfolding between Earth and the Sun. What say you?

[tniickck]

 i would say that sone of the protons are being held by the CME and they will start rising (maybe even to S3) a few tens of minutes before CME arrival

[hamateur 1953]

Wow.  Have we seen an S 3 yet?  I can’t recall.  Certainly haven’t seen mid-level protons stay this high for so long @tniickck  

[tniickck]

11 minutes ago, hamateur 1953 said:

Wow.  Have we seen an S 3 yet?  I can’t recall.  Certainly haven’t seen mid-level protons stay this high for so long @tniickck  

not in this cycle. the previous top 1 for SC25 was on 18/07/2023 with 619 pfu peak

[Philalethes]

1 hour ago, Christopher Shriver said:

I am calling for others to remark on past observations which looked like this.

The "smoothness" of this proton event is remarkable, as it hardly aligns with any adjacent activity. This either suggests the large CME we observed recently in a partial halo had a lot of energy, or other dynamics are unfolding between Earth and the Sun. What say you?

I'm not sure if I've seen it exactly like this, but I'm always amazed at how the proton flux even from single events can keep rising for so long after the actual event. I think that's the case here too, and that it's all from yesterday's CME, which did indeed look quite energetic. I've always assumed that it happens due to how the protons can get caught up in a lot of different spiraling trajectories that eventually reach our detectors, but at different times; e.g. a proton traveling more radially along a magnetic field line will reach us much sooner than one traveling along the same field line more tangentially (and thus also with a larger gyroradius).

So going by this I assume that the large spike (and subsequent drop) in the proton flux yesterday was from a big cluster of protons that had been ejected into a specific trajectory that all led to them arriving in closer temporal proximity, and that we're then seeing the continued rise from protons that are less clustered, as well as now probably starting to see signs of the rise anticipating the incoming CME.

18 minutes ago, hamateur 1953 said:

Wow.  Have we seen an S 3 yet?  I can’t recall.  Certainly haven’t seen mid-level protons stay this high for so long @tniickck  

Not so far this cycle if my memory serves me right, but we were really close yesterday with that peak at 956.

[hamateur 1953]

1 minute ago, Philalethes said:

I'm not sure if I've seen it exactly like this, but I'm always amazed at how the proton flux even from single events can keep rising for so long after the actual event. I think that's the case here too, and that it's all from yesterday's CME, which did indeed look quite energetic. I've always assumed that it happens due to how the protons can get caught up in a lot of different spiraling trajectories that eventually reach our detectors, but at different times; e.g. a proton traveling more radially along a magnetic field line will reach us much sooner than one traveling along the same field line more tangentially (and thus also with a larger gyroradius).

So going by this I assume that the large spike (and subsequent drop) in the proton flux yesterday was from a big cluster of protons that had been ejected into a specific trajectory that all led to them arriving in closer temporal proximity, and that we're then seeing the continued rise from protons that are less clustered, as well as now probably starting to see signs of the rise anticipating the incoming CME.

That makes sense to me @Philalethes

[Christopher Shriver]

53 minutes ago, Philalethes said:

I'm not sure if I've seen it exactly like this, but I'm always amazed at how the proton flux even from single events can keep rising for so long after the actual event. 

So going by this I assume that the large spike (and subsequent drop)

I believe you've mischaracterized the graph. It dropped, but it then held a steady proton flux for several hours, to this minute(update: it began rising again a little while ago). What could possibly cause such flatness? Lack of perturbations seem to indicate that we're along/within the boundary of that partial halo, as it continues to expand outwards, but such mass along the boundary of a CME could then support a theory framework I read on this website years ago, which attempted to model CME shockwaves.

I am biting my tongue now as the proton flux just began to rise again. Let's see what happens.

Edited March 24 by Christopher Shriver
tongue bitten

[helios]

Here's a comparison with the progress of earlier proton events (3 month timespan).
I think the slow progress is not very uncommon so far.

[Philalethes]

1 minute ago, Christopher Shriver said:

I believe you've mischaracterized the graph. It dropped, but it then held a steady proton flux for several hours, to this minute. What could possibly cause such flatness?

I should definitely have phrased it a bit more clearly. What I meant to say is that in the time after an eruptive event which ejects protons, there will be a period where the measured flux at L1 increases on average due to protons at different radial speeds arriving, although there is apparently (and not unexpectedly) some clustering in these varying speeds, so that you get a "jagged" movement in the flux; but on average it will increase for some time after the event. Then at a certain point it will tend to even out and reverse, but I guess this is the phase where you can get a more even flux like we're seeing in this case, especially if the drop is counteracted by the incoming protons that precede the CME, in which case you could expect a relatively flat plateau for at least a little while. I suppose one could check the archive and see if similar has been observed for similar types of events, where the proton flux is starting to drop after an event, but then starts rising due to an incoming CME.

Here I've drawn a crude illustration of what I mean, with the black line being what I consider to be the general evolution of the flux, interrupted by the big cluster we saw yesterday and possibly the CME that's incoming now:

But I should say that this is just how I contextualize the varying aspects of how the flux develops; I'm certainly not precluding any possibility of models specific to the eruption that could help explain what we measure even better and more accurately, or better yet even predict it (e.g. perhaps predict various clusters and plateaus from just coronagrams and UV imagery, based on some underlying CME model).

[tniickck]

33 minutes ago, helios said:

Here's a comparison with the progress of earlier proton events (3 month timespan).
I think the slow progress is not very uncommon so far.

where is this from? thank you in advance

[Christopher Shriver]

41 minutes ago, Philalethes said:

I should definitely have phrased it a bit more clearly. What I meant to say is that in the time after an eruptive event which ejects protons, there will be a period where the measured flux at L1 increases on average due to protons at different radial speeds arriving, although there is apparently (and not unexpectedly) some clustering in these varying speeds, so that you get a "jagged" movement in the flux; but on average it will increase for some time after the event. Then at a certain point it will tend to even out and reverse, but I guess this is the phase where you can get a more even flux like we're seeing in this case, especially if the drop is counteracted by the incoming protons that precede the CME, in which case you could expect a relatively flat plateau for at least a little while. I suppose one could check the archive and see if similar has been observed for similar types of events, where the proton flux is starting to drop after an event, but then starts rising due to an incoming CME.

Here I've drawn a crude illustration of what I mean, with the black line being what I consider to be the general evolution of the flux, interrupted by the big cluster we saw yesterday and possibly the CME that's incoming now:

But I should say that this is just how I contextualize the varying aspects of how the flux develops; I'm certainly not precluding any possibility of models specific to the eruption that could help explain what we measure even better and more accurately, or better yet even predict it (e.g. perhaps predict various clusters and plateaus from just coronagrams and UV imagery, based on some underlying CME model).

Very interesting. I've been eyeballing this on the side of what I'm currently dealing with: snow, lol. I may just miss whatever this spot does for the next several hours.

I'll review that post again, but preliminarily it appears you've clarified what was meant, so thanks. The proliferation of a steady energy state is notable for a few reasons.

[helios]

1 hour ago, tniickck said:

where is this from? thank you in advance

Made it myself, but here is a not so big but automatically updated version:
https://rrdstats.ddns.net/swpc/