Relative auroral emission intensity within view of Athabasca on April 5, 2010 at 09:05 UT in the 557.7 nm emission line, shown over a map centered on central Alberta. Major rivers and political boundaries are shown as white lines, and lakes as black regions. The wider context of the map may be found by reference to Fig. 9. Regions of little or no emission are shown in black, and the most intense emission is shown in white.