F 2 region ion densities from analysis of O+ 834‐Å airglow: A parametric study and comparisons with satellite data

A multiple-scattering radiative transfer model is used to infer F2 region ion densities from measurements of the O+ 834-A dayglow obtained from a spinning satellite. A parametric study is performed to demonstrate the sensitivity of the 834-A intensity profiles to variations in the solar ionizing flux, neutral atmospheric composition, and ionospheric density distribution. Results show that the solar flux and neutral densities govern the magnitude of the O+ 834-A intensity, but the shape of the intensity profiles as a function of look angle depends on the distribution of ions. Selected comparisons of the model results with the STP 78-1 EUV airglow data show that the height of the F2 peak, the peak ion density, and scale height of the ionosphere can be determined from the satellite data. Near the magnetic dip equator the data show increased intensity in the zenith look direction and increased limb brightening due to the effects of the upward plasma drifts associated with the equatorial anomaly. The parametric study shows that the behavior of the optical data is consistent with an upward movement of the height of the F2 peak in the anomaly.

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