Technique for introducing low-density space charge into the atmosphere

A technique for modifying the natural fair-weather electric field over large areas by the introduction of artificially produced space charge is described. The apparatus consists of a fine horizontal wire supported on insulators and maintained at a high voltage by a d-c power supply. With a 0.013-cm-diameter wire 4.5 km long and 4 m high maintained at 12 kv of negative polarity a corona current of about 1 ma flows, and the normal fair-weather electric field is reversed for a distance of 10 km or more downwind. The experimental observations are in fair agreement with a simple theory.