Comparative analysis of two new empirical models IRI-Plas and NGM (the Neustrelitz Global Model)

Empirical ionospheric models are under continuous development and the new model versions need to be tested and validated. In this paper two new models, the International Reference Ionosphere-Plasmasphere (IRI-Plas) and the Neustrelitz Global Model (NGM) are compared to the standard International Reference Ionosphere (IRI) in different geographical areas. Comparison is fulfilled separately for foF2, ТЕС, the equivalent slab thickness τ. In a middle-latitude area, the foF2(NGM) model has not improved results of foF2(IRI). For subauroral areas, conditions have appeared at which foF2(NGM) provides comparable or better results than foF2(IRI). In low-latitude and equatorial areas, there are conditions when foF2(NGM) is closer to experimental data than foF2(IRI). In middle- and high-latitude areas, TEC(NGM) and TEC(IRI-Plas) provide better results, than TEC(IRI). The IRI-Plas model is better than NGM except for winter months. In low-latitude and equatorial areas, the ТЕС(NGM) model has shown essential advantages. The parameter τ(NGM) provides in most cases the better conformity of the calculated foF2 with observational ones than τ(IRI) and τ(IRI-Plas).