Aurora spectra showing broad hydrogen lines

Abstract

The best spectra of the aurora taken since 1939 with the two prism spectrograph having camera lens ten cm focal length and F/1.65 aperture show lines, approximately five A broad, within two to five A of the positions of Hα, Hβ and Hγ. Large scale microphotometer tracings separate these lines from the various bands of N , and the identification as hydrogen seems established. Many spectra taken on the time sequence spectrograph, aperture F/0.8, show that these lines appear most strongly preceding and during an outburst of aurora. This is in support of Eckersley's theory of ionosphere disturbances. Thus, there is evidence to indicate that the hydrogen is of solar origin and a primary cause of some aurora outbursts and magnetic storms.