The effects of f0F2 variability on TEC prediction accuracy

Abstract

In this paper hourly daily F2-layer critical frequency data recorded at Rome and one minute daily TEC data recorded at Florence were used and the relevant variabiles were calculated. It was concluded that there was no clear evidence as to how they correlated. In order to obtain a measure of the f0F2 and TEC variability, the normalised differences df0F2 and d TEC from the relevant monthly median values were also considered. Since no clear evidence could be obtained as of how df0F2 and d TEC correlate, a new parameter, the ΔAP/ΔR ratio was tried. ΔAP was taken as the difference between the maximum value of AP measured at the relevant disturbance and that corresponding at the beginning of the disturbance. ΔR corresponded to the two above mentioned values of AP. This parameter was compared to the differences of the corresponding df0F2 values called Δ df and dTEC values called Δ dT. In wintertime, when ΔAP/Δ R was negative, for the vast majority of the occurences either Δdf or ΔdT was negative; Δdf and ΔdT were never observed to be negative at the same time whereas they were both positive in fewer than 10% of the observations. When ΔAP/ΔR was positive then either Δdf or ΔdT were negative. In summertime when ΔAP/ΔR was negative both Δdf and ΔdT were negative. When ΔAP/ΔR was positive, while a positive Δdf corresponded almost always to a positive ΔdT, a negative Δdf would equiprobably indicate either a positive or a negative ΔdT.