October 29, 2003 Aurora Borealis

I had heard reports of a geomagnetic storm coming so I checked out the space weather activity graphs. I was stunned to see the aurora activity scale pegged at >1000nT. The latitude pace was pure white. All the various ground and satellite-based magnetic sensors were pegged at their gates (see Kp index chart below).

Kp index chartIt was off the charts...beyond the range of the measuring instruments. The Bz hadn't shifted south yet (if that doesn't happen the magnetosphere does too good a job of reflecting the particles to be able to see anything). I decided to go ahead and head out because if it was to shift south I wanted to be in the right place knowing that it may not last long. So, I grabbed my camera, tripod, GPS and jacket around 1:30am and headed out to my pre-selected spot just for a time such as this. Totally flat...no tree line...no lights...no traffic...no houses. Behind a weight limit sign on a gravel road and only accompanied by some wildlife.

There it was...a bright greenish-white florescent-lightish color arc the shape of a squat rainbow about 30 degrees above the horizon. It was bright enough to look like full-moonlight and backlit some clouds that were in the way. I snapped some pictures and figured I'd hang around for a while to see if anything better happened. Well, I was about to fall asleep or drive back when around 2:30 the clouds had cleared out and the sky literally exploded into an array of color and shapes. The Bz had suddenly shifted southward (see the drop at 8:30Z in the Bz chart below).

BZ chartEveryone's seen this stuff in pictures and TV and such. But I thought it just sits there and swirls around a bit. The docile looking arc of light expanded up into the sky within a matter of minutes and shot angular rays of bright green light into the sky beyond 90 degrees above the horizon....beyond straight-up. More than half the sky was consumed by aurora. In the area where the spikes ended straight up in the sky there were large blobs of pure red dancing around like lava lamp globules. The green spikes were rolling across the sky like a fan backlit by a bright light. There were flashes of green and red light all over the north half of the sky, just totally random flashes like little explosions. It was bright enough to easily drown out the light from the stars behind it. Bigger and better than anything I expected to see here.

Aurora activity can cause a phenomenon called Auroral backscatter which causes transmitted radio waves to propagate longer than normal distances from one point on the Earth to another. FM radio usually doesn't have a range much beyond 50 miles but I was able to get two Canadian FM radio stations (one in Toronto) from my location in Iowa.

The pictures I took didn't turn out well, as expected. My camera has no manual shutter function so the shots were too dark.

The Bz swung north again and ended the show about 30 minutes after it began. It turned back into the docile arc that it was before. So, I came back home. There may be a chance of seeing something tonight as well. Here's an alert that would have been nice to know about but couldn't access because their site was down from too many people trying to hit it:

Event #49 - 28 October 2003
Issued: 16:30 UTC, 28 October 2003
Estimated Impact Window: 00:00 UTC on 29 October to 21:00 UTC on 29 October
Preferred Predicted Impact Time: 08:00 UTC, 29 October 2003 (3 am EST on 29 October)
Estimated Shock Strength (0=Weakest, 9=Strongest): 9
SEVERE to MAJOR geomagnetic storming is expected to abruptly commence following the arrival of the shock front from this flare.
This flare was associated with a Ground-Level Event. It was also associated with very high energy protons at greater than 100 MeV (which are still climbing, over 5 hours after the event began). A magnetic crochet was observed over the daylit sections of the ionosphere. An exceptionally intense shortwave fadeout and polar cap absorption event are in progress. There are reports this event was observed in white-light. Intense radio bursts were associated with this event across the spectrum. The type II shock velocity is not representative of the observed velocity of this CME. The observed velocity as determined by SOHO was 2125 km/sec.
This event has the potential to produce the strongest geomagnetic storm since 1989. Auroral activity could become visible into the deep low latitude regions. This one is worth driving a good long distance over to find clear skies. It has better potential to produce low-latitude aurora than almost any other event observed in the past decade. Keep in mind that it is also possible the disturbance may not be nearly as geoeffective as many would like. It all depends on the character of the magnetic fields imbedded within the coronal mass ejection. However, we believe it will either be very large, or only modestly large in terms of its capacity to produce disturbed geomagnetic and auroral activity. We do not expect this disturbance to be small.

Definitely not a small disturbance! People as far south as Texas and Alabama saw it. 2am central time they predicted...got here at 2:30am...pretty close.


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