Electron precipitation during the magnetospheric substorm on 27 July 1979

A method is described, by which the energy spectra of precipitating electrons may be deduced from the N-h profiles of sporadic E-layers produced by them. This is applied to the deduction of the electron energy spectra at quarter-hourly intervals from 0000 to 0200 UT on 27 July 1979 at Sanae, Antarctica, during which a magnetospheric substorm occurred. The electron spectra are found to agree well with those observed near Sanae or in its conjugate area by the DMSP-F2 satellite during this period. It is concluded that precipitating electrons were mainly reponsible for the occurrence of the sporadic E-layers, and variations of the energy spectra of these electrons during the storm are described