Parameters of large‐scale TEC disturbances during the strong magnetic storm on 29 October 2003

The total electron content (TEC) data obtained by the GPS network and GPS radio interferometry methods developed by the authors has made it possible to determine the spatial structure and dynamics parameters of large‐scale traveling ionospheric disturbances (LS TID) generated during the strong magnetic storm on 29 October 2003. It was shown that the LS TID registered in the auroral zone after a sudden storm commencement (SSC) represented a large‐scale solitary type wave with an annular front shape whose center was located near the geomagnetic pole. The wave had a period of about 40–60 min and traveled up to 4500 km equatorward. The relative amplitude of the LS TID was 5–10%. Comparison with ionosonde data has shown that this value corresponds to the relative amplitude of electron density disturbance in the F layer maximum of about 45–50%. The velocity and travel direction of the LS TID had a strongly pronounced longitudinal dependence. A “swirling” effect was detected in the LS TID movement, the direction of which was opposite to the Earth's rotation. The westward directed zonal projection of LS TID velocity caused this “swirling” effect. In the morning and evening sectors the zonal projection exceeded the meridional one. The diurnal movement of the ionization maximum may influence the zonal transfer of LS TID.