The Holzworth and Meng model of Auroral Oval (GRL Sept 75, vol.2,no.9,pg. 377) was used to determine the oval position. The cusp was based on the cusp study of Newell and Meng (JGR,vol.93,no.a12,pg.14,549). The oval position computed in corrected geomagnetic coordinates was transformed to geographic coordinates and plotted, using IGRF coefficients for year 1995 to transform from corrected geomagnetic coordinates to geographic coordinates. The equatorward edge of the oval was computed for high geomagnetic activity (Q-index of 6), and the poleward edge of the oval was computed for low geomagnetic activity (Q-index of 0).
The darkened side of the image corresponds to the nightside of the Earth. The terminator was computed at a 0 km altitude.