PJM issued a geomagnetic disturbance warning, then an action. No emergency actions, and it's already over.
Msg ID: 104606
Message Type: Geomagnetic Disturbance Action
Priority: Action
Effective Start Time: 06.01.2025 09:31
Effective End Time: 06.01.2025 12:25
Regions COMED
A Geomagnetic Disturbance Action has been issued as of 09:31 on 06.01.2025 to protect
the power system from damage or disruptions due to increased geomagnetic activity.
Times are "Eastern Prevailing Time", which is Eastern Daylight Time right now.
Background:
These messages are from the US east coast power grid control room in Valley Forge, PA sending to people at generating stations and other key control centers. This is a slow-moving event. If the grid was stressed, there would be "Pre-Emergency Load Reduction" and "Conservative Operation" actions ordered. If there was real trouble, there would be many more actions. But things never got beyond preparing for trouble.
A geomagnetic disturbance event in 1989 caused transformer damage leading to outages. The solar flux going between power lines and conductive ground induces DC currents into the ground and lines, so that ground potential is different at different points. This causes partial saturation of transformers, and heating. That wasn't noticed until it was too late. So now, DC current in some key AC lines is monitored continuously, so power levels can be reduced if necessary.
Training materials for understanding this:[1] Start at slide 21.
Background info on how a power grid works.[2] Start with "PJM 101"
> Times are "Eastern Prevailing Time", which is Eastern Daylight Time right now.
I'm trying to recall when I last ever saw "Eastern Prevailing Time" used.
Can anyone share why it's used?
I see more use of ET over that (for Eastern US) or better yet UTC/GMT.
op00to 1 days ago [-]
It removes ambiguity between ET (which do I mean?), EST (oops I meant EDT), and EDT (oops I meant EST).
I suspect they probably had an issue related to this, and prevailing time seems to work for them.
UTC is probably better, but a little less intuitive for most people.
xhrpost 2 days ago [-]
> So now, DC current in some key AC lines is monitored continuously...
Can power lines have multiple currents in them at once? What would that mean for when the AC phase is moving opposite the DC direction?
andy99 2 days ago [-]
AC is a sinusoid at 60/50 Hz. In principle, adding a DC current is just an offset, so e.g. if you had 1 Amp of AC current it would look like a sine wave 1 Amp high (actually sqrt(2)=1.414 high using the usual convention but that's not important) and the wave would be centered at 0A so go from -1(.414) to 1(.414). If you had a DC current of -1A on top of that, it would just be offset by that amount, so would look like a sine wave with a minimum of -2.414 and a maximum of .414.
Tldr, DC is just like an offset to the voltage or current waveform which is itself a sine wave.
globular-toast 1 days ago [-]
Electrical conductors are basically reservoirs of electrons that can move around freely. Think of a body of water like the ocean. There is a lot of movement happening all at the same time: the tides, the waves, rip currents etc.
A wire is an essential one dimensional conductor; the electrons can move only backwards or forwards. Think of a narrow channel of water like a canal or river. A canal has no current, while a river has a direct current: it always flows one way. But a tidal inlet has an alternating current. The net flow of water is zero, but there is still a constant movement of water, backwards and forwards.
At a tidal estuary both things are happening: there's a DC component caused by net egress of water and an AC component caused by the tide.
The analogy doesn't really work because bodies of water also have capacitance. Wires are more like pipes. But hopefully you get the idea. Another way to think of it is like shouting in the wind, if you know how sound works.
Look into Fourier transforms if you're interested in learning more.
Apparently my browser does not support some content in the file I'm trying to view and I'm instructed to use, among other things, "Firefox undefined or later". Which may or may not be what I was trying to use to begin with.
Though it seems to work anyway, so okay then.
zoky 2 days ago [-]
> "Firefox undefined or later"
Honestly, you should really upgrade to at least Firefox Null for the security updates, or even Firefox NaN if you’re okay with being on the bleeding edge.
Animats 2 days ago [-]
That PJM training material uses some ancient Adobe product. Works fine, though.
qwertox 2 days ago [-]
M8.2 is in the upper medium range (M = M1.0 to M9.9). Next comes X1 which is 10 times stronger than M10. M2 is 10 times stronger than M1.
We might see several of these per year during a solar maximum. So maybe we get some nice auroras.
Edit, TIL: Though the G4 is a different issue, which classifies the impact of a solar flare on our earth. These range from G1 (minor) to G5 (extreme). This means that it can disrupt radio communications and GPS, put stress on power grids and, interestingly, increase satellite drag. G4 storms are rare events and occur only a few times per 11-year solar cycle.
nozzlegear 2 days ago [-]
> G4 storms are rare events and occur only a few times per 11-year solar cycle.
Did you mean G5 storms? If I'm reading NOAA correctly, we get about 100 G4 storms per cycle, but only 4 G5 storms per cycle.
was reading something about this last week. originally, I assumed that the satellite electronics were getting whacked, but that wasn't the actual reason. these storms can heat the atmosphere causing it to expand/swell during the heating which causes extra drag requiring faster than anticipated use of fuel for station keeping.
just another one of those issues of just how everything in the universe "works together" in the most interesting ways.
perihelions 2 days ago [-]
A while back an entire Starlink launch was lost due to this atmospheric inflation,
I've read there was a huge solar flare in the 19th century that knocked out telegraph equipment all over the world. Do we know how strong that event was on that scale?
I know absolutely nothing about solar weather beyond aurora visuals being a possible outcome depending on where you live. I missed the last chance to see at my latitude (rare) and don't want to miss again.
What could I subscribe to so as to be notified when such events happen?
mikeocool 2 days ago [-]
The Aurora app on iOS can set to send a critical notification when you’re likely to see it in your location.
It alerted me (in New York) this morning at about 4AM — though I slept through it.
pyrophoenix 2 days ago [-]
It means between an hour and 9 hours from now, we might have a Aurora down to Berlin level at 100%. Now the weather is not the best. More information in 2 hours.
BenjiWiebe 2 days ago [-]
Note that this was published yesterday. The geomagnetic storm is underway right now.
lucasban 2 days ago [-]
I’ve been using the “My Aurora Forecast & Alerts” app, which is pretty good. I’m using the pro version, but I think the main difference was removing some ads.
On October 10th 2024 there was an x1.8 event and it was basically right at us. First time I’d seen the aurora - happened to be on cape cod at the time where the light pollution isn’t so bad. Was pretty amazing with the naked eye but absolutely incredible in long exposure photos.
sva_ 2 days ago [-]
> CME Passage Continues; G3-G4 Still Possible Tonight, June 1st
https://solarham.com/ says "arrived faster than expected" and "threshold was reached at 08:00 UTC"
and the website linked, the https://www.spaceweatherlive.com/en/.html says "14:00 UTC - Geomagnetic activity Severe G4 geomagnetic storm (Kp8)" followed by "17:30 UTC - Geomagnetic activity Minor G1 geomagnetic storm"
sva_ 2 days ago [-]
NOAA: "CME Passage Continues; G3-G4 Still Possible Tonight, June 1st"
Good luck to any directional drillers out there trying to drill your well blind.
JumpCrisscross 2 days ago [-]
?
kapnap 2 days ago [-]
It's kind of a running joke when you work as a Drilling Engineer and the Directional Driller says they can't confirm their coordinates due to magnetic storms.
It's a reference to the "Armageddon" movie from 1998 when a bunch of oil rig drillers get recruited into being astronauts for plot reasons. It was a decent enough movie but nothing you need to look up unless you have an unhealthy obsession for Arwen from Lord Of The Rings.
timschmidt 2 days ago [-]
I always felt that Armageddon occupied this uncanny valley of Hollywood cheese. Too much to suspend disbelief, not enough to be making fun of itself. Always loved "The Core" for being the same sort of film but falling into the second camp.
mrguyorama 22 hours ago [-]
Check out Angela Collier discuss how "The Core" is a better science movie than Armageddon
Don’t forget Deep Impact, sort of a summer companion blockbuster, but which “astronomers said was more accurate”, could feed your Hobbit obsessions, and NASA went on to name a space probe after it!
Negative - when directional drilling a well, a magnetic storm can actually cause you to lose signal and halt the entire drilling process. It's kind of a running joke when you work as a Drilling Engineer and the Directional Driller says they can't confirm their coordinates due to magnetic storms.
If I had to guess, I would say that Earth's magnetic field is used in directional drilling to tell which way your drill head is going and that the solar storm distorts Earth's magnetic field.
SoftTalker 2 days ago [-]
Wonder why they don't use gyros. Too much vibration?
_Microft 2 days ago [-]
They might be - this was only an attempt to make sense of the first comment in the context of this submission.
Background:
These messages are from the US east coast power grid control room in Valley Forge, PA sending to people at generating stations and other key control centers. This is a slow-moving event. If the grid was stressed, there would be "Pre-Emergency Load Reduction" and "Conservative Operation" actions ordered. If there was real trouble, there would be many more actions. But things never got beyond preparing for trouble.
A geomagnetic disturbance event in 1989 caused transformer damage leading to outages. The solar flux going between power lines and conductive ground induces DC currents into the ground and lines, so that ground potential is different at different points. This causes partial saturation of transformers, and heating. That wasn't noticed until it was too late. So now, DC current in some key AC lines is monitored continuously, so power levels can be reduced if necessary.
Training materials for understanding this:[1] Start at slide 21.
Background info on how a power grid works.[2] Start with "PJM 101"
[1] https://pjm.adobeconnect.com/p63ultsdb2v/
[2] https://www.pjm.com/training/training-resources
I'm trying to recall when I last ever saw "Eastern Prevailing Time" used.
Can anyone share why it's used?
I see more use of ET over that (for Eastern US) or better yet UTC/GMT.
I suspect they probably had an issue related to this, and prevailing time seems to work for them.
UTC is probably better, but a little less intuitive for most people.
Can power lines have multiple currents in them at once? What would that mean for when the AC phase is moving opposite the DC direction?
Tldr, DC is just like an offset to the voltage or current waveform which is itself a sine wave.
A wire is an essential one dimensional conductor; the electrons can move only backwards or forwards. Think of a narrow channel of water like a canal or river. A canal has no current, while a river has a direct current: it always flows one way. But a tidal inlet has an alternating current. The net flow of water is zero, but there is still a constant movement of water, backwards and forwards.
At a tidal estuary both things are happening: there's a DC component caused by net egress of water and an AC component caused by the tide.
The analogy doesn't really work because bodies of water also have capacitance. Wires are more like pipes. But hopefully you get the idea. Another way to think of it is like shouting in the wind, if you know how sound works.
Look into Fourier transforms if you're interested in learning more.
Apparently my browser does not support some content in the file I'm trying to view and I'm instructed to use, among other things, "Firefox undefined or later". Which may or may not be what I was trying to use to begin with.
Though it seems to work anyway, so okay then.
Honestly, you should really upgrade to at least Firefox Null for the security updates, or even Firefox NaN if you’re okay with being on the bleeding edge.
We might see several of these per year during a solar maximum. So maybe we get some nice auroras.
Edit, TIL: Though the G4 is a different issue, which classifies the impact of a solar flare on our earth. These range from G1 (minor) to G5 (extreme). This means that it can disrupt radio communications and GPS, put stress on power grids and, interestingly, increase satellite drag. G4 storms are rare events and occur only a few times per 11-year solar cycle.
Did you mean G5 storms? If I'm reading NOAA correctly, we get about 100 G4 storms per cycle, but only 4 G5 storms per cycle.
https://www.swpc.noaa.gov/noaa-scales-explanation
was reading something about this last week. originally, I assumed that the satellite electronics were getting whacked, but that wasn't the actual reason. these storms can heat the atmosphere causing it to expand/swell during the heating which causes extra drag requiring faster than anticipated use of fuel for station keeping.
just another one of those issues of just how everything in the universe "works together" in the most interesting ways.
https://news.ycombinator.com/item?id=30267587 ("Starlink lost 40 satellites to a geomagnetic storm (spacex.com)", 495 comments)
https://en.m.wikipedia.org/wiki/Carrington_Event
The instruments to measure the strength of solar flares didn't exist, but I think it's estimated between X40 to X50.
For comparison, last may the strongest flare was X8.7
https://en.m.wikipedia.org/wiki/May_2024_solar_storms
What could I subscribe to so as to be notified when such events happen?
It alerted me (in New York) this morning at about 4AM — though I slept through it.
https://www.swpc.noaa.gov/communities/space-weather-enthusia...
https://www.swpc.noaa.gov/content/subscription-services
https://community.spaceweatherlive.com/topic/3947-ar14100-m8...
Although it often sounds like people throwing fancy words around just to sound smart. And their predictions mostly dont work out
https://www.swpc.noaa.gov/news/cme-passage-continues-g3-g4-s...
---
NOAA map (https://www.swpc.noaa.gov/products/aurora-30-minute-forecast) shows huge auroras were at ~7-9 UTC and now are gone
https://solarham.com/ says "arrived faster than expected" and "threshold was reached at 08:00 UTC"
and the website linked, the https://www.spaceweatherlive.com/en/.html says "14:00 UTC - Geomagnetic activity Severe G4 geomagnetic storm (Kp8)" followed by "17:30 UTC - Geomagnetic activity Minor G1 geomagnetic storm"
https://www.swpc.noaa.gov/news/cme-passage-continues-g3-g4-s...
https://www.swpc.noaa.gov/communities/radio-communications
https://www.usgs.gov/communications-and-publishing/news/gett...
https://www.youtube.com/watch?v=5l5KHIFIl7U
https://en.wikipedia.org/wiki/Deep_Impact_(film)
https://en.wikipedia.org/wiki/Deep_Impact_(spacecraft)
https://www.usgs.gov/communications-and-publishing/news/gett...