Large‐Scale Traveling Ionospheric Disturbances Over the European Sector During the Geomagnetic Storm on March 23–24, 2023: Energy Deposition in the Source Regions and the Propagation Characteristics

• Published in: Journal of Geophysical Research: Space Physics
• Main Authors: Nykiel, Grzegorz, Ferreira, Arthur Amaral, Günzkofer, Florian Ludwig, Iochem, Pelin, Tasnim, Samira, Sato, Hiroatsu
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2024
• Subjects: Institut für Solar-Terrestrische Physik; Solar-Terrestrische Kopplungsprozesse; EISCAT; Northern Norway; Svalbard
• Online Access: https://elib.dlr.de/203311/; https://elib.dlr.de/203311/1/JGR%20Space%20Physics%20-%202024%20-%20Nykiel%20-%20Large%E2%80%90Scale%20Traveling%20Ionospheric%20Disturbances%20Over%20the%20European%20Sector%20During%20the.pdf; https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2023JA032145

Multiple Large-Scale Traveling Ionospheric Disturbances (LSTIDs) are observed in the European sector in both day-time and night-time during the magnetic storm on March 23–24, 2023. The Total Electron Content (TEC) observation from a network of GNSS receivers shows the propagation of LSTIDs with amplitudes between around 0.5 and 1 TECU originating from auroral and polar cusp regions down to southern Europe (35°N) with velocities between around 500 and 1,600 [m/s]. We study the energy deposition to the LSTIDs in the source regions and the resulting horizontal propagation over storm-time background density by using continuous measurements of EISCAT incoherent scatter radars in northern Norway and Svalbard that allow for estimating the source energy to the thermosphere-ionosphere system via Joule heating and particle precipitation. Both EISCAT and GNSS TEC data show that the electron density decreased to 50% in the auroral zone after the storm onset. The ionospheric heating caused a nearly 250% increase in the electron temperature above 200 km altitude and the ion temperature above 100 km altitude. We find that Joule Heating acts as a primary energy source for the night-time LSTIDs triggered in the auroral region, while the day-time LSTIDs can be also driven by precipitating particles in the polar cusp. We also find that a significant background density decrease over the whole European sector is caused by this storm for the following day, during which almost no clear LSTIDs are observed.