Comparative studies of Ionospheric models with GNSS and NavIC over the Indian Longitudinal sector during geomagnetic activities

Abstract

This paper presents the storm time comparative analysis of the performances of latest versions of global ionospheric models: International Reference Ionosphere (IRI) 2016, NeQuick 2 (NeQ) and the IRI extended to Plasmasphere (IRI-P) 2017 with respect to Navigation with Indian Constellation (NavIC) and Global Navigation Satellite System (GNSS) derived ionospheric Total Electron Content (TEC). The analysis is carried out under varying geomagnetic storm conditions during September 2017-November 2018, falling in the declining phase of solar cycle 24. TEC data from Indore, located near the northern crest of the Equatorial Ionization Anomaly (EIA) along with data obtained from the International GNSS Service (IGS) stations at Lucknow, located beyond the anomaly crest; Hyderabad, located between anomaly crest and magnetic equator and Bangalore, located near the magnetic equator have been analysed. The models generally overestimated during the storm periods with the exception of IRI-P, which matched (with an offset of about 3-5 TECU) with the enhancement observed on September 7, 2017 (during the strong storm of September 2017), from stations around the anomaly crest. No significant match was observed by the other two models. This match of IRI-P is attributed to the plasmaspheric contribution as well as the capability of assimilating measured TEC values into this model. In the present study, to the best of our knowledge, first comparisons of the empirical model derived TEC with NavIC and GNSS measurements from an anomaly crest location, combined with the IGS observations from the magnetic equator to locations beyond the anomaly crest, are conducted during geomagnetically disturbed conditions. Since NavIC satellites are at higher altitudes(~ 36000 km), the inclusion of NavIC data to the existing model could give better ionospheric predictions over the Indian subcontinent.

42 pages, 13 figures. Accepted for publication in Advances in Space Research

Cited by in corpus (8)

• Study of the equatorial ionosphere using the Giant Metrewave Radio Telescope (GMRT) at sub-GHz frequencies
• Systematic study of ionospheric scintillation over the indian low-latitudes during low solar activity conditions
• Exploring Earth's Ionosphere and its effect on low radio frequency observation with the uGMRT and the SKA
• Ionospheric response during Tropical Cyclones-a brief review on Amphan and Nisarga
• Global asymmetry in $\Delta$X variations during the 06 April 2000 geomagnetic storm: Relative roles of IMF Bz and By
• On the Low-Latitude Ionospheric Irregularities under Geomagnetically Active and Quiet Conditions using NavIC observables: A Spectral Analysis Approach
• Study of Low-latitude Ionospheric Scintillation using NavIC
• Evidence of changes in the low-latitude plasma drift under IMF $B_z$ coupling: a TIEGCM simulation approach