A comparative study of observed Ionospheric critical frequency (using ionosonde) and the IRI-2016 model

Abstract

In the present study, we compare the observed values of foF2 (ionospheric f2 layer critical frequency) and ionospheric empirical modal IRI-2016 predictions. To accomplish this study we used the period of January to December 2016 which was the low solar activity period (declining phase of solar cycle 24th). For this study, we have selected a low latitude station SANYA, CHINA (18.34° N 109.42° E), a mid-latitude station ATHENS, GREECE (38.0° N 23.5°E), and a high latitude station YAKUTSK, RUSSIA (62.00° N 129.60° E). We examined monthly as well as seasonal variability of the ionosphere in comparison with IRI-2016 over all the three latitudes. Our analysis found that the monthly values of observed foF2 were maximum during March, May, and June for the low, mid, and high latitudes, respectively, while minimum values were observed during December at all three latitudes. For seasonal analysis, we found that the highest values of foF2 were recorded during the winter season while the lowest values were recorded in the equinox seasons of all three stations. When correlating between observed and model data, we found that the model is most suitable for mid-latitude, and its coefficient of correlation is 0.78.