Fusing GOLD Satellite-Derived and Ground-Based Madrigal TEC for Global Ionosphere Analysis

This study investigates the feasibility of fusing satellite-inferred and ground-based TEC measurements to enhance global ionospheric specification and characterization. The TEC values are derived from the GOLD satellite’s 135.6 nm oxygen emission using the methodology of Qin et al. (2023) and are statistically calibrated to account for inherent assumptions in the derivation process. The calibrated GOLD-derived TEC is then integrated with the Madrigal ground-based TEC measurements and used as input for the VISTA model. To improve data integrity, filtering is applied to exclude contamination from solar and polar auroral emissions. Additionally, large-scale background TEC structures are separated from small-scale depletions such as Equatorial Plasma Bubbles (EPBs) by a rolling ball algorithm described by Pradipta et al. (2024), and constructed as a validation dataset for numerical models that do not explicitly incorporate EPB physics. Using the VISTA data based on the fused TEC input, our preliminary results provide new insights into equatorial and midlatitude ionospheric dynamics, such as the hemispheric asymmetry of EIAs. This work underscores the potential of multi-source TEC fusion in advancing our capability of specifying the ionosphere and understanding ionospheric phenomena, such as equatorial plasma bubbles.