Characteristics of the O+(2P-2D) 732.0 and 733.0nm airglow emissions observed with WINDII and simulated with the C-IAM

Abstract

This paper provides new data on the O+(2P- 2D) 732nm and 733nm daytime airglow emissions that enhance our understanding of the role that local and conjugate photoelectrons play in the excitation of this emission, updating earlier investigations of its production by solar EUV photoionization of neutral atomic oxygen. The Wind Imaging Interferometer on the Upper Atmosphere Research Satellite, launched in 1991, retrieved these emissions using a filter primarily intended for observations of the hydroxyl P1(2) line but with invalid results. The first corrected results are presented here and compared with simulations by the Canadian Ionosphere and Atmosphere Model. Reasonable agreement is obtained in terms of vertical profiles, solar flux, and solar zenith angle variations. Observations made during local twilight demonstrate that conjugate photoelectrons do not contribute to the excitation of this emission. This paves the way for future determinations of atomic oxygen concentrations. Key Points O+( 2P) emission is observed with a Doppler Michelson interferometer, WINDII Emission rate profiles agree well with simulations by the a model It is demonstrated observationally that photoelectrons are not responsible © 2014. American Geophysical Union. All Rights Reserved.