The red and near-infra-red auroral spectrum

Abstract

Six auroral spectra covering the wavelength range 5400-8800 Å have been subject to thorough intensity measurements. The intensity distributions in the First Positive band system and the Meinel band systems were measured and related to theoretical data. The altitude variations of these band systems and the strongest oxygen lines and bands were studied, the intensity ratio between the red [O I] lines λ6300/64 and the First Positive bands being taken as an indication of relative altitude. An auroral feature detected at 7325 Å on spectra from high altitudes is tentatively identified as the [O II] multiplet 2D - 2P. The intensity distribution and its variation with altitude are briefly discussed. © 1957.