Speaker
Description
In this study, we analyze and compare the Ionosphere-Thermosphere (I-T) response over Central Europe to the two severe geomagnetic storms occurred in October 2024 and January 2025. Ionosonde observations from Rome (41.8°N, 25.5°E) and Juliusruh (54.6°N, 13.4°E) were manually validated and used to characterize ionospheric variability and to retrieve thermospheric parameters—neutral composition, temperature, and wind—around local noon using the THERION method.The derived storm-time parameters are compared with outputs from the empirical MSISE00 model, highlighting the limitations of climatological approaches in capturing rapid I-T variability.
Complementary GNSS-based total electron content (TEC) data were employed to better characterize the ionospheric response, while ground-based geomagnetic field measurements from the INTERMAGNET network were analyzed to investigate the ionospheric electric current system variations.
The different behaviour revealed by THERION analysis is explained by typical F2-layer storm mechanisms during different seasons, with negative electron density variations observed in October due to compositional disturbances carried from high latitudes, and weak positive effects in the midday F2 layer in January.
These findings contribute to improving the understanding of storm-time variability of the mid-latitude I-T system and its impacts on space weather conditions, with implications for GNSS-based applications and communication systems operating in disturbed environments.
This study was carried out within the Space It Up project funded by the Italian Space Agency, ASI, and the Ministry of University and Research, MUR, under contract n. 2024-5-E.0 - CUP n. I53D24000060005.
