Large-scale traveling ionospheric disturbances over central and eastern Europe during moderate magnetic storm period on 22-24 September 2020

We present the results of ground based remote sensing observations of large-scale traveling ionospheric disturbances (LSTIDs) occurring during the moderate magnetic storm evolution (22-24 September 2020) over central and eastern Europe. Three ionosondes located in Juliusruh, Pruhonice and near Kharkiv, and the Kharkiv incoherent scatter radar were employed to study temporal and spatial LSTID signatures in ionospheric F2 peak density and height and electron density variations at the heights of 100-300 km. Two types of LSTIDs are detected, which are originated during enhancement in auroral activity (2 events) and local sunrise terminator passage (3 events) from the ionosonde data. The magnetic storm-related LSTIDs exhibit equatorward propagation with the horizontal phase velocities of 546 m/s and 576 m/s, similar dominant periods of 135-150 min and 165-180 min over all three sites and a longitudinal dependence in fractional (relative) amplitudes of electron density perturbation. The solar terminator induced LSTIDs demonstrate the variety in both relative amplitudes and dominant periods over different locations. They have a westward apparent horizontal phase velocities of 288-345 m/s, which are close to the solar terminator velocity at ionospheric heights. Employment of incoherent scatter data enabled the detection of additional LSTIDs over Ukraine with the periods in a broader range of 41-168 min, an establishment of phase and onset differences for the oscillations in the ionospheric F2 peak electron density and height. (c) 2023 COSPAR. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).