Ionospheric Absorption Variation Based on Ionosonde and Riometer Data and the NOAA D-RAP Model over Europe During Intense Solar Flares in September 2017. - Veronika Barta; Tamás Bozóki; Dávid Péter Süle; Daniel Kouba; Jens Mielich; Tero Raita; Attila Buzás (Remote. Sens., 2024)