Observations of unusual structures of high-latitude stratospheric electric fields

We report the observation, by means of balloon-borne sensors, of three cases of unusual stratospheric electric field structures at high latitudes. In all three cases a region of downward directed electric field is flanked by regions with upward field. In two out of the three cases, the central downward field is much stronger than the average fair weather field. The vertical current densities involved are <5×10^-11 A/m². These field structures are observed only about 0.5% of the time.