Reexamination of ionospheric photochemistry

This paper reexamines the chemistry of N2+, NO+, O2+, and N+ by comparing densities from a photochemical model with data from the Atmosphere Explorer C satellite. These comparisons show that the measurements of N2+, NO+, O2+, and N+ density are well modeled with up‐to‐date reaction rates, solar EUV irradiances, and photoelectron fluxes. In particular, this study has resolved a long‐standing problem wherein the previous investigations overestimated the measured N2+ density by a factor of 2. A new method of determining the important and controversial O+(2D) + N2 reaction rate from the Atmosphere Explorer C data is presented. This reaction rate determination agrees well with the latest laboratory measured reaction rate. Key Points The ionospheric ion densities are well modeled The ionospheric ion densities are compatible with model solar EUV fluxes The aeronomically determined reaction rates match laboratory measurements