VARIATION IN HEIGHTS OF THE LOWER BORDERS OF AURORAL BANDS

Abstract

The variation in height of 20 well-defined auroras has been measured over projected distances from 70 to 401 km. Differences in height as large as 55 km have been found between two points on the lower borders of a band. Half the auroras measured showed relatively small variations, the other half considerable. These facts may need to be taken into account in the use of single-station photographs of bands for determining auroral properties such as heights and widths.