Electrical Properties of Oceanic Tropical Clouds at Ponape, Micronesia

Abstract

Abstract Ground-based observations of the electrical properties of oceanic tropical clouds were made in Ponape (7°N, 158°E), Micronesia, in both October 1976 and October 1977. In addition, specially designed radiosonde systems were used for in-cloud measurements during the latter observational period. Warm clouds in Ponape, although higher than those in Hawaii, produce the same variations in electric field at the ground, and raindrops exhibit the same electrical charge as those from warm clouds in Hawaii. Radiosonde observations in thunderstorms indicate that negatively charged particles, probably graupel, form in the temperature region between 0 and −40°C, and fall to the ground as negatively electrified large raindrops. Radiosonde observations of the electrical charge on particles in thunderstorms indicate that the in-cloud distribution of charge in Ponapean thunderstorms is the same as the well-recognized electrical structure in midlatitude thunderstorms. In-cloud electrical charge separation may be ex...