Comparison of IRI_PLAS and IRI_2012 model predictions with GPS_TEC measurements in different latitude regions

The International Reference Ionosphere (IRI) is an empirical model for providing ionospheric parameters, including Total Electron Content (TEC), electron density, electron and ion temperature etc., in the altitude range from 50 km to 2000 km. Since the IRI model is limited up to 2000 km, IRI_PLAS model, plasmasphere extension of the IRI model, was proposed by the researchers. This paper investigates the TEC prediction performance of IRI_PLAS and IRI_2012 models by comparing GPS TEC data, in different latitude regions for magnetically active and quiet days. TEC data over 9 International GNSS Service ( IGS) stations, located in different latitude regions, are used for the comparison. Evaluation of the diurnal results reveals good agreement with correlation coefficient >0.9 between GPS_TEC and empirical models for the quiet day irrespectively of the latitudinal data used. However, while the differences are not relatively large in most part of the active days, they reach high level, above 30 TECu, in some parts of the days.