Indexes of the ionosphere variability during geomagnetic storms as deduced from GPS observations

Indexes of the positive and negative disturbance of the total electron content NT in the ionosphere and plasmasphere are calibrated in the degree of logarithmic deflection from the quiet median for the previous 27 days. Data are used from orld maps GPS-IONEX along the meridian of 30° E in the latitudes from 10 to 60° N for 1999-2006. The index scale NT determines quiet conditions, moderate disturbances, moderate and strong storms in the ionosphere. The comparison between NT indexes and 69 intensive magnetic storms at DstT without succeeding decay; about 30 % are the cases of the NT negative storm phase without positive one; less than 50 % of storms are those with the well-known general-type scheme of positive and negative NT phases