Our planet's magnetic shield is again under stress today with brief G3 Strong geomagnetic storm levels reached around 09:00 UTC. The storms began on September 7 with positive polarity coronal hole reaching geoeffective position and an impact of plasma filament eruptions from September 4th and 5th. Aurora images we've seen over the last 4 days are astounding, be sure to check out some of them at the end of this article.
Geomagnetic K-index of 5 (G1 Minor geomagnetic storm) threshold was first reached at 15:00 UTC on September 7. K-index of 6 (G2 Moderate) threshold was reached at 16:25 UTC that day.
With changing intensity, the storming continued until September 10, when K-index sharply dropped, and intensified again to 7 (G3 Strong) at 08:59 UTC on September 11.
By 09:36 UTC today, this brief period of G3 Strong storm was over. However, enhanced geomagnetic activity is not over yet and we might experience more isolated periods of moderate to strong storming over the next couple of days.
