1981 年 33 巻 5 号 p. 297-318
By using two-dimensional observations of ground magnetic perturbations with the Scandinavian Magnetometer Array and by incorporating some simultaneous electric field observations made by the STARE radars, an attempt is made to model the threedimensional current system in the late morning sector during a substorm recovery phase on February 16, 1977. During the recovery phase of substorm activity a localized region of net upward field-aligned current drifts to the east. This current is apparently carried by drift precipitation of energetic electrons which has been observed earlier by balloon and satellite spectrometers under the same geophysical conditions. The precipitating electrons responsible for the upward field-aligned current seem to shortcircuit the westward electrojet Hall current and cause its divergence up magnetic field lines. Equatorward of the auroral oval the precipitating electrons create a high-conducting channel where an eastward current is flowing. This current is probably a Cowling current and is decreasing in the eastward direction. While it remains open how this current is fed into the ionosphere, we content that the total eastward current is also diverging up magnetic field lines.
