Field-aligned current observed on ISEE-2 in the innermagnetosphere

Field-aligned currents in the inner magnetosphere arc studied by using ISEE-2 magnetometer da-la, A method is proposed to calculate ×B with single-satellite data. From the morphology of ×B in time (or L). a lot of large fluctuations are found in ×B near L = 5.5RE corresponding to the field-aligned currents. Statistical study shows that the field-aligned current in the inner magnetosphere is a function of B, L, MLT and AL. The region of the projections of ×B along the magnetic field line onto the ionosphere is not symmetrical for the geomagnetic pole. The inner boundary is independent of the geomagnetic disturbance, but during substorms the outer boundary shifts equatorward. The spatial distribution of the in- and out-flowing currents is complicated. The region-1-and-2 system is hardly distinguishable.