Performance evaluation of IRI-Plas 2017 model with ionosonde data measurements of ionospheric parameters.

This study presents an evaluation of the performance of the International Reference Ionosphere Model augmented with the Plasmasphere (IRI Plas 2017) from the Addis Ababa Ionosonde Station, Ethiopia, for measuring ionospheric parameters at geographic (9.00 N, 38.70 E) and geomagnetic (0.16 N, 110.44 E) location on selected days of 2014. During comparison hourly and daily variability of the ionospheric parameters of the electron density profile (Neh), maximum electron density (NmF2) and maximum height (hmF2) measurements are considered. When evaluating the IRI Plas model using ionosonde data, the percentage deviation and correlation coefficient (R) were used as measures of IRI Plas model performance. In general, the overall results of the study show that the IRI Plas 2017 model mostly overestimates at most altitudes and hours of electron density measurements. The IRI Plas model has an acceptable fit with the ionosonde electron density measurements at altitudes of 100 km-200 km, mostly during the hours between 03LT and 09 LT and 15 LT-21 LT, while the model biases in other altitudes and hours with overestimates or underestimates in the ionosonde electron density measurements. The IRI-Plas 2017 model has a good correlation after midnight and around midday hours, with about ±2% point deviation from the ionosonde electron density measurement. The model has a high percentage deviation value for electron density measurements, mostly between altitudes of 200 km and 450 km and during early nighttime and before midnight hours. IRI-Plas model measurements of NmF2 and hmF2 are mostly underestimated from the ionosonde data during the nighttime (21 LT-09 LT) and overestimated during the daytime (09 LT-21 LT). The NmF2 values measured with the model are more consistent with ionosonde values than hmF2 values.