Comparative Analysis of Meridional and Azimuthal Propagation of Magnetic Variations and Equivalent Current Vortices of Geomagnetic Pc5 Pulsations

Abstract

The propagation velocities of geomagnetic Pc5 pulsations in the azimuthal and meridional directions were analyzed for a series of events. Two methods were used: based on the phase delays of the signal between stations and the displacement of vortex centers of their equivalent current systems. The analysis showed that the propagation of pulsations and vortices coincides in direction—along the meridian, they predominantly propagate northward. In most cases, the propagation velocity is 5 km/s for pulsations and 2 km/s for vortices. In the azimuthal direction, pulsations and vortices propagate westward, with pulsation propagation velocity of 10 km/s and vortex propagation velocity of 3 km/s. However, the distributions of azimuthal velocities for both pulsations and vortices exhibit comparable maxima corresponding to eastward propagation: pulsations at a velocity of 10 km/s and vortices at 5 km/s. It is concluded that the measured phase velocities of pulsations at the ionospheric level are approximately twice the group velocities of vortices.