ELECTROSTATIC FIELD CHANGES PRODUCED BY FLORIDA LIGHTNING.

Abstract

The electrical behavior of thunderstorms triggered by local heating and sea-breeze convergence, a low pressure disturbance, and a weak frontal passage has been studied at the NASA Kennedy Space Center, Florida. A nonlinear least-squares minimization procedure has been developed to describe changes in the total electrostatic field produced by lightning in terms of point charge models for the cloud charge distributions. The results indicate that discharges to ground usually neutralize cloud charges in the range from minus 10 to minus 40C. A large fraction of the discharges to ground show total field changes which are small or even reversed in polarity within 3 km of the discharges. An analysis of these cases suggests that ground discharges often neutralize a small positive charge, 0. 5 to 4C at altitudes of 1 to 3 km, in addition to the larger negative charge higher in the cloud.