Comments on the interpretation of 3371 Å filter-photometer observations and its implications for the AE-E photoelectron fluxes

Modeling of the dayglow spectrum in the wavelength region between 3300 and 3500 Å indicates that the N₂ second positive (0,0) band at 3371 Å is blended with the Vegard-Kaplan (0,9) band. A recent analysis of rocket observations of the dayglow shows that 20–30% of a 3371 Å narrow band filter-photometer signal is due to the VK emission (Conway and Christensen, 1983). Kopp $\text{et al.}$ (1977) and Hernandez $\text{et al.}$ (1983) reported analyses of 3371 Å photometer observations from the Visible Airglow Experiment on the Atmospheric Explorer-C (AE-C) satellite which did not consider the Vegard-Kaplan (VK) emission. The observations were compared to theoretical estimates of the second positive volume emission rate based on a photoelectron model and on absolute fluxes measured by the Photoelectron Spectrometer experiments on AE-C and AE-E. Inclusion of the VK band in the AE analysis would bring the reported photoelectron theory into agreement with the airglow observations. However, the overestimate of the N₂ second positive airglow predicted by the AE-E photoelectron flux measurements increases to a factor of nearly two rather than the 20–30% reported by Hernandez $\text{et al.}$ (1983).