On the Relationship of the O(1D) 630.0 nm Dayglow Emission to the F10.7 cm Solar Flux and the Solar Zenith Angle

The Wind Imaging Interferometer (WINDII) Empirical Model, which provides the characteristics of the O(1D) 630.0 nm atomic oxygen dayglow emission from the upper atmosphere has been reviewed and updated. It now includes the Integrated Emission Rate, the peak Volume Emission Rate, the Altitude of that peak and the Full Width at Half Maximum as functions of the F10.7 cm Solar Radio Flux and the solar zenith angle (SZA). The model employs 98,617 WINDII observations obtained between the years 1992 and 1996, and the model and observations of the Integrated Emission Rate agree well with one another within 2 standard deviations of 588.7 Rayleigh (R) (106 photons cm−2 sec−1). It is also demonstrated that the impact of latitude, longitude and day of year, independently of their contribution to the SZA, is very small. The WINDII Empirical Model is also shown to agree with results from the TRANSCAR photochemical model. The dayglow is challenging to measure with ground‐based instruments, as the solar scattered light from the daytime sky must be accurately subtracted from the data. Ground‐based measurements of the integrated emission rate have been made by others, with good agreement for observations from Hyderabad during the 2015 summer and winter, but mixed agreement with measurements made over Boston in 2003. The latter results are reviewed and assessed. Plain Language Summary The airglow is light emitted by the upper atmosphere, roughly from 80 to 300 km altitude, owing to the solar energy that is absorbed during the day, causing chemical reactions that emit this airglow light, and which continues during the night. The daytime airglow, called dayglow, is created only during daytime. This light is difficult to observe from the ground because of all the much greater sunlight scattered from the lower atmosphere (all the way down to ground level). Looking tangentially above the Earth’s surface, satellite instruments can see the dayglow without having to look through the scattered light of the lower atmosphere. This study describes observations made with a satellite instrument called the Wind Imaging Interferometer (WINDII), which flew on NASA’s Upper Atmosphere Research Satellite from 1991 to 2003; which was well suited to observing dayglow. While the dayglow emission processes are complex in principle, WINDII has shown that the dayglow can be characterized by just two numbers, the solar radio flux (F10.7) at 10.7 cm wavelength, and the angle between the zenith (straigh