Empirical Models of foF2 and hmF2 Reconstituted by Global Ionosonde and Reanalysis Data and COSMIC Observations

The F2-peak plasma frequency (foF2) and the height of the F2 peak (hmF2) are two of the most important parameters for any ionospheric model, as well as radio propagation studies and applications. In this study, we have developed empirical models to capture the most significant variations of foF2 and hmF2. The derived empirical models (referred to as the USTC models within this study) are specified through global ionosonde and reanalysis data based on the International Reference Ionosphere (IRI) Consultative Committee on International Radio (CCIR) method and Constellation Observindg System for Meteorology, Ionosphere, and Climate (COSMIC) observations based on the empirical orthogonal function analysis, respectively. The USTC models are validated against the IRI CCIR model prediction. The comparison results revealed that the empirical foF2 model performs better in capturing the foF2 variations than the IRI CCIR model, which can overcome the underestimation of the IRI CCIR model at low latitudes. Although the IRI CCIR model overestimation at middle latitudes is addressed by the empirical hmF2 model, the visible differences between the model predictions and ionosonde observations still exist at low latitudes, which could be attributed to the significant difference between COSMIC and ionosonde hmF2 measures. foF2 and hmF2 are important parameters for radio propagation studies and applications. In this study, empirical models of foF2 and hmF2 are respectively developed to describe the climatological variabilities based on the global ionosonde and reanalysis data and Constellation Observindg System for Meteorology, Ionosphere, and Climate (COSMIC) observations, and the self-verification suggests a good model performance. Other than the underestimation at low latitudes of the International Reference Ionosphere (IRI) Consultative Committee on International Radio (CCIR) model, the newly developed model performs well in reproducing the foF2 variations when validated with the ionosonde measurements. Additionally, the developed model overcomes the overestimation of the IRI CCIR model at middle latitudes, while maintaining visible gaps from the ionosonde observations at low latitudes, which could be due to the significant systematic deviations between COSMIC and ionosonde in hmF2 measurements. The developed model serves reference for scientific studies and practical applications in the future. The empirical models of foF2 and hmF2 are respectively reconstituted by using ionosonde and reanalysis data, and Constellation Observindg System for Meteorology, Ionosphere, and Climate (COSMIC) observations The empirical foF2 model displays a better performance for capturing foF2 variations compared to the International Reference Ionosphere Consultative Committee on International Radio model The empirical hmF2 model has a different performance at different latitudes affecting by the COSMIC observations