Аннотация:he role of inner magnetosphere currents in the magnetopause dynamics is analyzed. The change of magnetopause position under the influence of inner magnetosphere magnetic field sources is analyzed. It is shown that the main source of such change may be an effective eastward ring current flowing near the
inner edge of the plasma sheet. This current produces negative equatorial magnetic field disturbance in the near tail region and can be considered as one of the main elements of substorm dynamics explaining substorm beginning deep in the magnetosphere not far from the geostationary orbit.