This project is to investigate the source of a newly discovered terrestrial airglow feature at 3276 and 3279 angstroms attributed to the [OII] (O+) doublet (2D - 4S) emission. Observations have been and will be made with a new class of highly sensitive interference spectrometer called the Spatial Heterodyne Spectrometer (SHS). The airglow feature of interest, first detected in 1958 but only observed a few times since then, is believed to originate in the F region of the ionosphere, and the project aims to confirm the identification and investigate the emission's possible use as a tracer of ion chemistry and electron density. The dearth of observations is due to the faintness of the feature. The source of the ions is due to either photoelectrons impacting the sunlit upper atmosphere or precipitating electrons. Most recently, these terrestrial [OII] emission lines were inadvertently detected as part of a Galactic [OII] interstellar medium program underway at the University of Wisconsin's Pine Bluff Observatory. The SHS instrument will be used to study the details of the O+ emission at different viewing geometries and over differing geophysical conditions with unprecedented sensitivity, contributing to observational diagnostics of ionospheric constituents. The resulting database will be used to investigate where the [OII ] emission is generated and what are its effects on the ionosphere. Satellite data such as that from TIMED-GUVI will be examined for possible usefulness in interpreting the ground-based data acquired during the project. One of the broader impacts of this research is the development of spectral analysis codes that will be applicable to aeronomy data. Another is the application of a new spectroscopic technique to aeronomy applications as well as providing assistance to Galactic research studies. Outreach activities are planned in which the SHS data will be used for presentations to interest elementary and high school students in atmospheric research.
