MEASUREMENT OF ELECTRON DRIFT VELOCITIES IN NIGHT-TIME EQUATORIAL ELECTROJET

VHF radar observations of a type of electron density irregularity in the equatorial electrojet indicate that the night-time electron flow is in the reverse direction to that during the day. The magnitude of the electron drift velocity at night is comparable to that during day-time periods, and the reversal occurs typically at about 06.30 hours and 20.30 hours, local time. Data are presented which show the electron drift velocity as a function of time. Additional aspects of the diurnal variation of the drift velocity are outlined and briefly discussed. © 1969.