Accuracy of models of hmF2 used for long-term trend analyses

摘要: [1] One of the largest expected ionospheric effects increasing concentrations greenhouse gases is a decrease in height F2 region peak density, hmF2, by ∼20 km. Analyses long-term trends hmF2 historical data to confirm this change must rely on models based limited number ionogram characteristics, because full analysis analog (pre–digital age) ionograms derive plasma frequency profiles and was tedious usually rare procedure. This paper discusses accuracy three models/formulas that have been used for trend studies, namely (1) simple parabolic model, which sets equal virtual at 0.834 foF2, (2) Dudeney (1974, 1983) (3) Bilitza et al. (1979) model. The validated using calculated from given International Reference Ionosphere (IRI). best model would be one with smallest seasonal solar cycle variations errors, even if it has systematic error. Analysis errors (relative IRI) shows all are useful, but different times day.