Space Charge over the Open Ocean

Abstract

Atmospheric space charge density measurements were made over the open ocean from San Francisco to Pago Pago on board the U.S.N.S. Eltanin during November and December 1967, using a guarded Faraday cage. Analysis of these data and the meteorological data obtained by the ship's scientific staff indicates that high positive space charge densities occur only when there are whitecaps in the area and when there is an atmospheric mechanism present to transport air from the sea surface to deck height. It is also shown that a wind speed between 6 and 20 kt is not a precise indicator of whitecap activity. It seems highly probable that the high space charge densities which occur only under the above conditions are due to positively charged jet drops produced by the bursting of air bubbles at the air-sea interface.