Ionospheric constraints for mesospheric nitric oxide based on empirical models of the D-region Original Research Article

The formation of the daytime D-region crucially depends on the density of nitric oxide (NO). If other ionisation processes are assumed to be known or expected to be negligible, NO densities can be inferred, provided the effective recombination coefficient is known. A non-auroral D-region model based on rocket-borne wave propagation data only, together with the results during undisturbed conditions from a similar analysis from high latitudes provides the electron density basis from which NO densities are inferred. Two sets of NO density profiles are provided, one with the highest conceivable densities and another with the likely typical values.