Ionospheric indices GIX and SIDX as proxies to characterize spatial and temporal ionospheric perturbations degree

Abstract

Severe space weather events cause perturbations of the ionospheric plasma that, consequently, strongly affect the availability, continuity and accuracy of Global Navigation Satellite Systems (GNSS) signals and their application in telecommunication and navigation systems. With the purpose of assuring reliable information on space weather conditions and, in particular, on the perturbation degree of the ionosphere, the German Aerospace Center has developed the Gradient Ionospheric indeX (GIX) and the Sudden Ionospheric Disturbance indeX (SIDX) as proxies capable of estimating spatial and temporal perturbations degree of the ionosphere without the necessity to include historical data in the analysis.With our work, we present an overview about the performance of GIX and SIDX for characterizing spatial and temporal ionospheric perturbations in the framework of the Coordinated Ionospheric Study of Scales and Indices (CISSI) initiative, within the scientific activities of the Committee on Space Research (COSPAR). Namely, we report on the outcomes achieved with these approaches when applying them to GNSS datasets acquired over Europe and South America during selected periods of stormy and quiet geomagnetic conditions. Moreover, we examine the scientific potential of these ionospheric perturbation indices and discuss their applicability in space weather services.