Comparison of Measured High-Latitude F-Region Ion Composition Climatology Variability with Models
Advances in Space Research
Satellite measurements of the global F-region ion composition morphology, due to orbit-to-orbit variations in space and time, are most effectively examined statistically, taking into consideration the ranges of variability in the data. Simple averages of the measurements do not clearly delineate narrow and time varying features such as density troughs/holes, sharp ionospheric layers, or even auroral region enhancements of electron temperature/molecular ion concentrations. These in fact are the most prominent features seen along individual satellite passes and are features which have prominent climatological variations To explore how well current ionosphere models fare with reality at middle and high latitudes, the entire ensemble of available solar minimum satellite ion composition measurements (predominantly from Atmosphere Explorer C and D) are sorted into spatial, temporal and magnetic/solar activity indices bins. Ion concentrations obtained from multiple runs of the International Reference Ionosphere (IRI) and the Utah State University Time Dependent Ionosphere model (TDIM), sorted into bins similar to those used for the satellite data sets are compared to the measurements. As currently configured the IRI model does not make a good match with the middle and high latitude topside ionosphere ion composition measurements. The TDIM is a better match to the measurements but does not reproduce the deepest high latitude ionospheric troughs and auroral-cusp molecular ion enhancements.
Grebowsky, J. M., R. E. Erlandson, J. J. Sojka, R. W. Schunk, and D. Bilitza, Comparison of measured high-latitude F-region ion composition climatology variability with models, Adv. Space Res., 22, 885-894, 1998.