A technique for determining daytime atmospheric oxide above 50 km from backscattered ultraviolet measurements

Airglow from gamma band resonance fluorescence of nitric oxide near 255 nm is calculated at several solar zenith angles. Data from the Nimbus 4 BUV wavelengths 273.5 to 287.6 nm is used to estimate the Rayleigh and ozone scattering contributions to the BUV 255.5 nm data and the remaining signal is attributed to NO airglow. The low solar zenith angle contributions by NO is less than 0.5%, and the high latitude/high zenith angle contribution exceeds 5%. This technique allows for estimating NO content above 50 km, as well as partitioning that content between the mesosphere and thermosphere.