Variability of the electric currents in the magnetosphere

We used several thousand magnetic measurements in the distant magnetosphere to study differential responses of the magnetospheric currents to various geophysical parameters. It is shown that the growth of the solar wind dynam ic pressure intensifies the magnetopause and magnetotail currents. The IMF vertical component affects the Region 1 field-aligned currents. The substor m activity gives rise to growth of the cross-tail current. The storm develo pment is accompanied by the increase of both the ring and cross-tail curren t, the latter effect being dominant. (C) 1999 Elsevier Science Ltd. All rig hts reserved.