Thermospheric Composition and Solar EUV Flux from the Global-scale Observations of the Limb and Disk (GOLD) mission

Observations of far-ultraviolet (FUV) dayglow by the Global-scale Observations of Limb and Disk (GOLD) mission provide a new opportunity to monitor relative composition changes in the upper atmosphere as well as solar extreme ultraviolet (EUV) variability. Relative composition changes are measured through ΣO/N, which is the column density ratio of atomic oxygen to molecular nitrogen, while Q provides a measure of the solar EUV energy flux below 45 nm into the upper atmosphere. This spectral range provides the ionizing radiation which ultimately results in FUV airglow emission produced by photodissociation and photoelectron impact. The quantities ΣO/N and Q are derived from GOLD FUV observations through lookup tables that are constructed using a first-principles photoelectron transport model. The two FUV emission features used are O I 135.6 nm and N Lyman-Birge-Hopfield (LBH) bands as functions of...