Electric fields in the vicinity of auroral forms from motions of barium vapor releases

摘要: In August-September 1967 eleven barium vapor clouds were released during evening twilight between invariant magnetic latitudes of 67.3° to 68.1° from Andoya, Norwav. Two flights (8 releases) occurred moderate negative bays in H, whereas the third flight (3 took place a positive bay H. Visual auroral displays observed vicinity all flights. situation, ion cloud motions eastward and closely parallel arc alignments. Electric fields transverse field with intensities 10–130 mv/m directed southward observed. During event spanned breakup transition region, two equatorward moving westward while poleward went east. Observed reversals direction correlated variations. North-directed electric up 50 found sector. events revealed that E was perpendicular ionospheric current, hence we conclude electrojets, both westward, are essentially Hall currents. The results illustrate magnitude driving currents cannot be deduced solely ground observations because variable electrical conductivity. There is evidence large near an arc, within very low. Large gradients and/or irregularities exist most time. These on three different time-space scales: differences velocity for clouds, changes along path given cloud, form rayed structure cloud.