Aurora Borealis

Date: 15 December 2006 U.T.
Time: 2:00 - 4:15 U.T.
Transparency: Mostly Clear to Mostly Cloudy
Latitude: 45.5 North
Location: Northwestern U.S.

Shortly before 2:00 U.T. I stepped out the south door to check sky conditions. (The sky had been cloudy earlier.) I was greeted by a mostly clear sky and a strong glow in the east. A look out the north door verified my suspicion: An aurora was in progress.

A large, bright, pale green auroral glow extended from within Orion in the east-southeast through Auriga, Cassiopeia, etc. all the way to Cygnus in the northwest (basically following the Milky Way) and all points northward. The display consisted of an amorphous glow with a few, small, pulsating patches -- mostly in the northeast.

At roughly 15 minute intervals I checked on the auroral activity. Throughout my auroral watch the large glow described above remained visible. This glow had the appearance of a huge, broad dome. Its high point, in the direction of magnetic north, was within a few degrees of the zenith.

Around 3:15 U.T. a pulsating arc would occasionally appear and disappear in a matter of seconds, passing above Polaris.

By 3:45 U.T. the thin clouds were beginning to grow thicker everywhere. A short, bright, rayed-arc was visible near the horizon in the direction of magnetic north (a few degrees east of true north). This arc, in addition to the huge glow mentioned earlier, remained visible until the clouds became nearly opaque at 4:15 U.T.