Dynamics of total electron content distribution during strong geomagnetic storms

We proposed a method for calculation of global or regional maps of velocities of total electron content isolines (TECIL) displacements. Applying of our method to the global ionosphere maps allows us to obtain additional information about the ionosphere plasma redistribution. Thus, during the geomagnetic storms on 29–31 October 2003 we observed anomalous large enhancements of TEC (“hot spots” of ionization) with a velocity of TEC isolines movements more than 2000 m/s. The areas with anomalous enhanced TEC appeared in the southwest of North America from 12 to 16 LT, and the vectors of TECIL movements were orientated towards the center of the “spots”. We can conclude that the observed “spots” occurred due to intense accumulation of TEC from every quarter and, probably, were caused by simultaneous poleward movements of the crests of the equatorial ionization anomaly and equatorward traveling of large-scale disturbances generated in the auroral area at the main phase of geomagnetic storms.