May 2024 Geomagnetic Storms from AR 13664 (2)

[Ingolf]

48 minutes ago, Philalethes said:

Not sure what you mean by the Ap not using every single value; it's calculated from the average... 

Thanks for reply first. I mean what you wrote, its the average Kp value in 3h slots. It's not e.g. the speed, density or the most negative Bz. Its just Kp and thats why it is pretty difficult for me to say which storm is stronger than another. 

The short measured "energy" is higher in 2003 but overall it's 2024.

Interesting what you say about the split if a storm hits midnight. Its logical but gives room for failures in the ranking. 

Edited May 21 by Ingolf
Autocorrect 🙄

[Vancanneyt Sander]

9 uren geleden, Philalethes zei:

maybe a possibility to enable ranking by Ap

It was initially but it was indeed changed later maybe @Marcel de Bont knows why I changed it. Think it’s because people aren’t familiar with Ap and Kp is primary ranking ( so that strongest three hour period is primary ranking, secondary Ap for strongest overall whole day)

[hamateur 1953]

On 5/21/2024 at 9:43 PM, Vancanneyt Sander said:

It was initially but it was indeed changed later maybe @Marcel de Bont knows why I changed it. Think it’s because people aren’t familiar with Ap and Kp is primary ranking ( so that strongest three hour period is primary ranking, secondary Ap for strongest overall whole day)

Thanks for bringing that up, I have known about both. Honestly the A index has been transmitted by our NIST ( formerly National Bureau of Standards) on our time stations hourly by station WWV for years.  The Kp which I only rarely noted may be used now, I will check soon.  I and probably other radio listeners would typically only check WWV for daily solar flux which was also transmitted along with the Boulder Colorado  A index. I also was using a screen capture from The 10 yr anniversary production done by SWL so my comparison of the A index records was years old.  🙄. Mike 

On 5/21/2024 at 11:26 AM, Ingolf said:

The data from Potsdam is there and this geomagnetic storm is at the second place in the SWL Top 50 ranking of geomagnetic storms with an Ap of 271.

The Halloween Storm 2003 is listed at position 7 with an Ap 204.

The Ap doesn't use every single value in it's calculation. It depends very on the duration of a storm. 

Now the question, all the people always want to know "which storm was bigger", they always want to compare with something. We can read it so often with Carrington for example. 

So if someone is asking, which storm was bigger? Halloween or May 2024? 

Please say May 2024, I already made an Instagram story 🤣

Which storm is bigger?  I should know better by now.  It depends…. On just about everything.  

Edited May 23 by hamateur 1953
Typos. A index error

[Marcel de Bont]

4 uren geleden, Vancanneyt Sander zei:

It was initially but it was indeed changed later maybe @Marcel de Bont knows why I changed it. Think it’s because people aren’t familiar with Ap and Kp is primary ranking ( so that strongest three hour period is primary ranking, secondary Ap for strongest overall whole day)

Ap says nothing about a storm's peak strength. It just tells you how much geomagnetic activity there was on average over a 24 hour period. Getting peak Dst values would be the best for a proper storm ranking system but taking the max Kp value of a 3-hour period is a decent alternative as we do not have a Dst archive.

What you could get with a top geomagnetic storm list by Ap ranking is... if a CME hits late on a day and you get a Kp9 at the end of the day... but the rest of the day was mostly Kp0 or 1.... you get a really low Ap value and despite having a period where the Kp was 9, that day would be really low down on the list despite it having a period with a Kp value of 9

https://www.spaceweatherlive.com/en/help/the-ap-index.html

[Philalethes]

4 hours ago, Vancanneyt Sander said:

It was initially but it was indeed changed later maybe @Marcel de Bont knows why I changed it.

15 minutes ago, Marcel de Bont said:

if a CME hits late on a day and you get a Kp9 at the end of the day... but the rest of the day was mostly Kp0 or 1.... you get a really low Ap value and despite having a period where the Kp was 9, that day would be really low down on the list despite it having a period with a Kp value of 9

Yep, that's exactly the same criticism I made about it above, and why an 8-period running average would probably be more useful (but still have flaws, e.g. if a storm calms down and then picks back up a few periods later). Just thought it might be an idea to have the possibility of ranking by Ap (like how you can often click the header of a table to sort that specific column accordingly) for some idea about which full days had the most activity, but I agree it's not really that useful, especially due to that above criticism that you echoed here, so it's quite understandable not to include that.

19 minutes ago, Marcel de Bont said:

Getting peak Dst values would be the best for a proper storm ranking system but taking the max Kp value of a 3-hour period is a decent alternative as we do not have a Dst archive.

That'd be great to have, and could indeed serve as a good tiebreaker between all the days that have a peak of Kp9. I saw the Ap-/Kp-index data was added all the way back to 1932, so maybe something similar could be done with the Dst data from Kyoto (available back to 1957) at some point.

[Marcel de Bont]

Thanks for your input @Philalethes, Having a Dst archive would be the only proper way to rank extreme geomagnetic storms reaching the G5 threshold. Dst is the value everybody uses to rank these kind of major Kp9 storms. Right now we do not have such an archive so the way we rank them now based on maximum Kp for a given day is the most logical alternative. But yeah, using only the Kp you can not determine where the G5 storms rank among themselves of course. 

[Vancanneyt Sander]

5 uren geleden, Marcel de Bont zei:

Having a Dst archive would be the only proper way to rank extreme geomagnetic storms reaching the G5 threshold

Downside is that finalized Dst is years behind and that site is so badly created it will require a lot of work to even setup such database + a hassle to make it updateable as there is no clear schedule when preliminary goes finalised and when Quicklook becomes preliminary. 

[Christopher Shriver]

Meteorology has Space Weather beat, when it comes to a diversity of juxtapositions for data and its applicability.

I think the need for a re-hashing of Ap/Kp/Dst for public-facing interests may be warranted. Not suggesting that those are deprecated, but rather suggesting an idea to devise a new index which organizes and simplifies what is happening and when based on such information.

A professional effort at NASA/NOAA may be a far-flung dream, pending future developments of global interests in space, but we seem to be capable of identifying several critical points that help shape a new index for geomagnetic storming; perhaps one not devised expressly for conformity in research efforts, but one that provides a primary data point with display of the Ap/Kp/Dst around a given period.

A software engineer and a SWL nerd walk into a bar...

[hamateur 1953]

Where my own confusion began was ironically enough with the Halloween storms ratings.  Showing the Ap ratings of them at 6 and 16. Lacking a deeper insight. I assumed that Kp was merely a short-term predictive model and subsequent final Ap values would be published after all participants weighed in with their station readings.  Incidentally, I use the magnetometers in British Columbia closest to my location in preference to just about anything. As many here have suggested. In addition to the site Aurora dashboard of course. But this has taken some experience to get a good idea of my likelihood of local activity.  Worth all the effort BTW 🙂

Edited May 22 by hamateur 1953

[hamateur 1953]

6 hours ago, Christopher Shriver said:

Meteorology has Space Weather beat, when it comes to a diversity of juxtapositions for data and its applicability.

I think the need for a re-hashing of Ap/Kp/Dst for public-facing interests may be warranted. Not suggesting that those are deprecated, but rather suggesting an idea to devise a new index which organizes and simplifies what is happening and when based on such information.

A professional effort at NASA/NOAA may be a far-flung dream, pending future developments of global interests in space, but we seem to be capable of identifying several critical points that help shape a new index for geomagnetic storming; perhaps one not devised expressly for conformity in research efforts, but one that provides a primary data point with display of the Ap/Kp/Dst around a given period.

A software engineer and a SWL nerd walk into a bar...

I agree on the overall unit of measurement.  Was suggested awhile back in another thread “ value peaks”. 
“Elons “ for downed satellites.  Haha  later dudes!  

Edit: I think @3gMike explained the methods used to determine Ap to me sometime back. But it’s been so long, I have forgotten now.  What I do recall is if there are errors in Ap they will be reflected when calculating Kp values from Ap. 

Edited May 23 by hamateur 1953
Ap

[sky gazer]

Hello all, I have been reading this community's posts for over 6 months and finally decided to join.  I am curious about the May 10-11th storm.  While waiting for nightfall, I noticed these cloud formations.  There was minimal wind at ground level, and a faint purple aurora above them. Could the particles hitting the nitrogen affect the shape of the clouds in this way?  I've seen rain clouds but never falling at an angle like this

[helios]

1 hour ago, sky gazer said:

Could the particles hitting the nitrogen affect the shape of the clouds in this way?

I think not. The particles which are responsible for aurora don't have enough energy to make it to the troposphere, where clouds form.
The clouds in your picture look like normal virga clouds.

 

Although later in the night (after 02 UTC) There was an unrelated proton event with ground level enhancement, so particles actually made it to ground level. 

There are studies which suggest that cosmic rays can have an influence on cloud formation, but I have doubts that this is what happened in this case.

 

[hamateur 1953]

https://www.ngdc.noaa.gov/stp/geomag/dst.html  Since there has been a discussion of storm comparison methods and the term DST was new to me three years ago, I decided to look up what they were actually measuring to derive the DST numbers: Equatorial Ring Current. 
This I had heard of!  Haha. Only referred to by its effects.  Like cycles per second was a descriptive term until Hertz replaced it long ago.  Wild Will was correct in calling me “ a bit of a curmudgeon”.   @Philalethes may already have mentioned this but I just saw a graph of May10/11 displaying the DST reported by Kyoto as above -425 nt initially and gradually headed toward positive over the next few hours.  From HF underground a Ham Radio/ Shortwave Listeners resource I frequent  A later Edit :  posted link above to noaa in the event others are curious about DST. Mike 

Edited May 23 by hamateur 1953
Max DST. Added link.

[Vancanneyt Sander]

So, if we use Dst to rank storms, the top 10 geomagnetic storms since 1957 would be...

[hamateur 1953]

Kudos again to this site.  Its predictive abilities allowed me to view it at maximum intensity.   I live about 70 miles from the best viewing areas away from the Seattle glow and rolled in just in time.  Mike. Edit:  over the last two or three years the more I learned it seemed less and less likely that everything would line up to give us the show we received.  At least this time I was ready to drive to a previously picked site to witness it naked eye! 

Edited May 27 by hamateur 1953
Afterthought. typos

[Pom]

30th October 2003 is #10.
20th November 2003 is #6.

11th May 2024 is #7.
27th May 2024 ex-3664 coming into view again.

History repeating? 🌞

Shwing
Pom

Edited May 27 by Pom

[Philalethes]

1 hour ago, Pom said:

30th October 2003 is #10.
20th November 2003 is #6.

11th May 2024 is #7.
27th May 2024 ex-3664 coming into view again.

History repeating? 🌞

Shwing
Pom

It's a fun comparison, but it should be noted that the two storms originated from different regions in that case; the later stronger storm in November came from 10501, which seems to have corresponded to 10484 in the rotation before, a region which came a bit before the infamous 10486 that caused the Halloween storms (which is why the two storms are spaced a bit less than a Carrington rotation apart, at ~3 weeks instead of ~27 days). You can see the two regions in the archive here and click a rotation forward to see the correspondence.

Also worth noting that it seems like 10501 had weakened quite a bit by then, and that the CME that caused that storm was associated with a measly M5.57 (post-correction) flare (as seen here). As noted in this paper that was quite puzzling indeed, as while geomagnetic storming from CMEs associated with weak flares weren't news it was still a very extreme example, which motivated the writing of the paper itself:

Quote

The motivation of this study stems from the observation that the source active region did not exhibit any solar characteristics significant enough to render the intense storm on 20 November 2003. This is an exception from the other superstorms (Dst ∼ −300 nT) of the current solar cycle described by Srivastava (2005) and Gopalswamy et al. (2005). This event is therefore, significant from the perspective of space weather prediction and requires a detailed investigation in order to understand the factors leading to such an event. Although most super storms studied by Srivastava (2005) were associated with high-speed CMEs and strong X-class flares in large active regions, the most intense storm of 20 November 2003 (Dst ∼ −472 nT) had its source in a relatively smaller and weaker M3.9 class flare. This posed a real challenge for the space weather forecasters as the source of this geomagnetic storm was a CME with a moderate plane of sky speed of ∼1660 km s^(−1).

Not sure if I'd call 1660 km/s "moderate" myself, but I guess in terms of single CMEs causing large geomagnetic storms it might be apt.

In any case it goes to show that you can get big geomagnetic storms out of very little if the stars align (metaphorically speaking, of course, as well as with a tinge of punniness).

[hamateur 1953]

1 hour ago, Pom said:

30th October 2003 is #10.
20th November 2003 is #6.

11th May 2024 is #7.
27th May 2024 ex-3664 coming into view again.

History repeating? 🌞

Shwing
Pom

Shwing most definitely Garth!  Rockandroll. Haha.  Mike

[Pom]

On 5/28/2024 at 12:03 AM, Philalethes said:

It's a fun comparison,

Of course it was, you got it right. However, it seems AR3697 keeps delivering. BTW this is the way I got my high school diploma. I just wanted to make a joke and accidently it was exactly the right answer... 🤓

Ahoi
Pom

Edited May 29 by Pom