Suprathermal electrons in small‐scale field‐aligned currents

The data obtained from the Intercosmos‐Bulgaria‐1300 Satellite have shown that during strong magnetic storms a halo of suprathermal electrons with number density equal to 0, 1% of the ionospheric plasma density with effective transverse temperature of the order of several eV appeared in the region of the intense small‐scale (1 km) field‐aligned currents. These electrons are believed to be the main carriers of narrow field‐aligned currents. The observed approach to isotropy of the electron flux is interpreted in terms of Coulomb scattering, although it is hard to explain the electric fields necessary for the electron acceleration without the presence of anomalous resistance.