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.
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)
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://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://www.usgs.gov/communications-and-publishing/news/gett...
https://www.usgs.gov/communications-and-publishing/news/gett...
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
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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/news/cme-passage-continues-g3-g4-s...
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.
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"
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.
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.
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.
mobbin•8mo ago
What could I subscribe to so as to be notified when such events happen?
pyrophoenix•8mo ago
BenjiWiebe•8mo ago
olddustytrail•8mo ago
AStonesThrow•8mo ago
https://www.swpc.noaa.gov/communities/space-weather-enthusia...
https://www.swpc.noaa.gov/content/subscription-services
n3uromancer•8mo ago
lucasban•8mo ago
mikeocool•8mo ago
It alerted me (in New York) this morning at about 4AM — though I slept through it.