The following pictures of the aurora borealis (the "northern lights") were taken in the vicinity of Santa Barbara, CA, which is at latitude 34.4 degrees North (geomagnetic latitude of 39 degrees).  It is unusual for the aurora to be seen from this location, and it is possible only when there's a strong solar wind storm.  According to surface measurements of geomagnetic activity this picture was taken at the peak of the recent storm, registering a Planetary Kp Index of 9!

Figure 1.  March 30, 11 PM, looking east from San Marcos Pass region (altitude 2250 feet).  The 2-minute exposure was made with a 35-mm film Minolta camera, f/1.7 lens, mounted to a Meade ETX125EC for sidereal guiding (without guiding the stars would have formed tracks).  The brightest star is Alpha Serpens (upper-right); part of Hercules is at the left.  [Kodak Elite Chrome film was used, push-developed 1-stop, yielding ISO 800.]

When I arrived at this mountain site I had other goals, and being unaware that an aurora sighting was likely I first believed there was a forest fire nearby.  But the linear features, and fast-changing patterns (50% decorrelation time of about 20 seconds), soon led me to understand their true nature.  During the 2-minute exposure streaks came and went, and this picture is a record of several "events."  Visually, the overall brightness was slightly less than in this photo.  Thin cirrus was present, which accounts for some of the non-streaking structure.  The camera was mounted with the wide dimension east-west, which just happened to coincide with the orientation of the aural streamers.  I've rotated the image to make the horizon "level."
 

Figure 2.  Map of auroral activity at the time of the above photo (from http://www.sel.noaa.gov/pmap/index.html ), showing an almost unprecedented large area extent of activity.

Figure 3.  Plot of geomagnetic activity (due to solar wind storms) showing a peak at about 0600 UT, March 31.  The photo in Fig. 1 was taken at 0657 UT, March 31, essentialy coincident with peak activity.  (This graph is from http://www.sel.noaa.gov/rt_plots/kp_3d.html).

There's a good descriptuion of auroral matters at http://www.sel.noaa.gov/Aurora/

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This site opened:  March 31, 2001.  Last Update: April 1, 2001