| air discharge [`er `dis´chärj] GEOPHYSICS 1. A form of lightning discharge, intermediate in character between a cloud discharge and a cloud-to-ground discharge, in which the multibranching lightning channel descending from a cloud base does not reach the ground, but succeeds only in neutralizing the space charge distributed in the subcloud layer. 2. A type of diffuse electrical discharge occasionally reported as occurring in the region above an active thunderstorm. |