Talk:March 1989 geomagnetic storm

Description of effect on electrical grid is incorrect.

The article discusses the effects on the electrical grid, but the explanation, taken from a press release for popular consumption, is incorrect. What actually happens is that the geomagnetic storm induces a DC potential difference between distant points on the earth's surface. This results in DC current flows in AC transmission lines, because the centers of the high voltage sides of the wye-connected transformers at both end are grounded to earth at both ends. A DC current in an AC transformer results in partial saturation of the transformer core. The transformer is then a resistive device for part of its cycle, which results in transformer heating, and, in severe cases such as in 1989, melting. Saturation also causes the transformers to generate non-sinusoidal waveforms containing higher harmonics (second and fourth harmonics, mostly) of the power line frequency, an abnormal condition which will trip protective devices. DC potential differences as small as 12 VDC can induce this effect in high-voltage transmission-grid transformers.

Some moderately technical sources:

• PJM training on geo-magnetic disturbances (p. 6-24) [1]

• PJM Geomagnetic Disturbances (GMD): [2]

• NERC analysis of 1989 event. [3]

John Nagle (talk) 06:27, 15 November 2013 (UTC)

White Light Flare

I observed a white light flare associated with this event. I was wondering if anyone else saw it, too? I should have photographic evidence somewhere in my things... CielProfond (talk) 14:06, 23 July 2015 (UTC)

There is some really amateurish sounding language on this page . . .

I am not sure how to fix it so I will just call attention to it. Here goes . . .

In the "Geomagnetic storms and auroras" section:

In the first paragraph in the "Geomagnetic storms and auroras" section: "... an unknown number of people worried that a nuclear first-strike might be in progress". Really! The fact that "an unknown number of people" were "worried" about something" is useful/relevant how?

Also the first paragraph in the "Geomagnetic storms and auroras" section: "Others considered the intense auroras to be associated with the Space Shuttle mission STS-29, which had been launched on March 13 at 9:57:00 AM." Who are "Others"? On what grounds did they consider the auroras to be associated with STS-29? How precisely is this entire sentence relevant to anything at all?

The entire second paragraph in the "Geomagnetic storms and auroras" section is beyond words: ""As midnight came and went, a river of charged particles and electrons in the ionosphere flowed from west to east, inducing powerful electrical currents in the ground that surged into many natural nooks and crannies." Where do I begin? "As midnight came and went" (which timezone)?; "a river of charged particles and electrons" ("a river"? Really?); "... that surged into many natural nooks and crannies" ("nooks and crannies"? Really???)

The rest of the article is actually not bad although anyone reading the article from the beginning is going to have serious concerns about the article's credibility by the time they get through the "Geomagnetic storms and auroras" section.

Dabcanboulet (talk) 23:00, 16 November 2015 (UTC)

Fully agreed! CielProfond (talk) 15:02, 22 November 2015 (UTC)

External links modified

Hello fellow Wikipedians,

I have just modified one external link on March 1989 geomagnetic storm. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:

• Added archive https://web.archive.org/web/20130602100449/http://findarticles.com/p/articles/mi_m1511/is_n8_v16/ai_17253896/pg_1 to http://findarticles.com/p/articles/mi_m1511/is_n8_v16/ai_17253896/pg_1

When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.

This message was posted before February 2018. After February 2018, "External links modified" talk page sections are no longer generated or monitored by InternetArchiveBot. No special action is required regarding these talk page notices, other than regular verification using the archive tool instructions below. Editors have permission to delete these "External links modified" talk page sections if they want to de-clutter talk pages, but see the RfC before doing mass systematic removals. This message is updated dynamically through the template {{source check}} (last update: 5 June 2024).

• If you have discovered URLs which were erroneously considered dead by the bot, you can report them with this tool.
• If you found an error with any archives or the URLs themselves, you can fix them with this tool.

Cheers.—InternetArchiveBot (Report bug) 15:39, 22 May 2017 (UTC)