Reproducing TEC variations during May 2024 storm based on statistics

The ionosphere is a critical factor for the performance of a wide range of communication and navigation systems. Sudden significant changes in its electron density can cause degradations in the performance of these technical systems. The variability of the ionosphere is mainly driven by solar EUV radiation, but solar wind can also modify the ionosphere significantly for periods of geomagnetic storms. The modelling of the solar wind driven variability of the ionospheric electron density is still an open challenge because of the very complex nature of the ionosphere response to the solar wind input. This study presents an attempt to reproduce the variability of the Total Electron Content (TEC) during one of the most recent extreme geomagnetic storms, which occurred on 10 May 2024.

18 years of TEC maps (2005-2023) provided by the International GNSS Service (IGS) are analysed for potential correlations with the popular geomagnetic index Kp. The analysis differentiates local and UT dependencies. The correlation results show a clear latitudinal dependence and hemispheric asymmetry. A linear regression model is generated for those conditions, where a significant correlation is detected. This statistical model is used to reproduce the storm in May 2024. The results are compared with the actual IGS TEC maps observed during the storm.