Comparative study of the polar region ionospheric NmF2 and IRI-2016 models

Abstract

The propagation of radio waves can be significantly affected by the ionosphere, which have a serious impact on broadcasting, communication, positioning and navigation. The International Reference Ionosphere (IRI) provides multiple ionospheric parameters for given location, time and date. In order to study the applicability of the IRI-2016 model in polar ionosphere, long-term observations from the dynasonde at Tromso (TRO), EISCAT Svalbard Radar (ESR) at Longyearbyen (LYB) and digisonde DPS-4 at Zhongshan (ZHS) were used to analyze the prediction accuracy of IRI model, with the help of mathematical statistics, correlation coefficients and time series. The data of F2 layer peak electron density (NmF2) are sorted as monthly medians of NmF2 for each hours, months, and solar activities. The results show that there is a good correlation between IRI prediction and observations during solar minimum years, with the correlation coefficients larger than 0.8 except winter at Longyearbyen, better than that during solar maximum years. The correlation decreases as latitude increases. It is the best at Tromso, and better at Zhongshan than at Longyearbyen. This suggests that the IRI-2016 model is mostly applicable at the auroral latitude station Tromso. But the IRI-2016 model has poor applicability at the cusp latitude station, both Zhongshan and Longyearbyen.