Assessment of the Performance of Ionospheric Models with NavIC Observations during Geomagnetic Storms

TL;DR

This study evaluates the accuracy of IRI-2016 and NeQuick2 ionospheric models against NavIC observations during geomagnetic storms near the Indian sector, highlighting their underestimation and need for real data integration.

Contribution

It provides a comparative assessment of global empirical ionospheric models with regional NavIC data during geomagnetic storms, emphasizing model limitations and the necessity for real-time data inclusion.

Findings

Both models underestimate TEC during storms.

Models fail to accurately predict storm-time TEC variations.

Real NavIC data improves model predictions.

Abstract

The paper presents an assessment of the performances of the global empirical models: International Reference Ionosphere (IRI)-2016 and the NeQuick2 model derived ionospheric Total Electron Content (TEC) with respect to the Navigation with Indian Constellation (NavIC)/ Indian Regional Navigation Satellite System(IRNSS) estimated TEC under geomagnetic storm conditions. The present study is carried out over Indore (Geographic: 22.52$^{\circ}$N 75.92$^{\circ}$E and Magnetic Dip: 32.23$^{\circ}$N, located close to the northern crest of the Equatorial Ionization Anomaly (EIA) region of the Indian sector). Analysis has been performed for an intense storm (September 6-10, 2017), a moderate storm (September 26-30, 2017) and a mild storm (January 17-21, 2018) that fall in the declining phase of the present solar cycle. It is observed that both IRI-2016 and NeQuick2 derived TEC are underestimates when compared with the observed TEC from NavIC and therefore fail to predict storm time changes in TEC over this region and requires real data inclusion from NavIC for better prediction over the variable Indian longitude sector.