St. Elmos Fire

A luminous, and often audible, electric discharge that is intermediate in nature between a spark discharge and a point discharge (with its diffuse, quiescent, and non-luminous character). It occurs from objects, especially pointed ones, when the electric field strength near their surfaces attains a value near 100,000 volts per m. Aircraft flying through active electrical storms often develop corona discharge streamers from antennas and propellers, and even from the entire fuselage and wing structure. It is seen also, during stormy weather, emanating from the yards and masts of ships at sea.