Electric charge on raindrops grown in warm clouds over the island of Hawaii

Abstract

Measurements of electric charge on raindrops in and beneath warm clouds over the Island of Hawaii were carried out with the use of radiosonde and ground equipment in the summer of 1965. In the case of shower type rain, raindrops were observed to have a considerable amount of positive electric charge while a reversal of the normal fair weather electric field intensity was observed at the ground level.

Radiosonde observations revealed that raindrops with positive charge were present in the lower part of clouds and that raindrops with negative charge predominated in the upper part.

In the case of continuous rain, the electric field intensity at the ground level showed increased positive values, and raindrops with negative charge were sometimes observed at the ground stations. The features of the electrification of raindrops in these different precipitation types are described.