Two balloon-borne experiments to measure electric field structure inside thunderstorms
Weber, Mark Edward
Few, Arthur A.
Master of Science
Two balloon borne instruments, capable of making in situ electrical measurements, have been flown into active thunderclouds. The Balloon Electric Field Sensor is a spherical field mill which measures the full vector electric field by making use of its simple relatioship to the surface density of induced charge on a conducting sphere. Analysis of data obtained in a flight on August 12,1976 is well under way and results are presented here. A simple device, compatible in every way with the standard meteorological radiosonde has been developed to measure the vertical electric field component within thunderclouds. This "Coronasonde" measures the corona current induced in a pair of antennae extending above and below the radiosonde box as an indication of the field which is inducing this current. Four flights, made in August of 1977, have produced data of interest. In particular, speculation on the possibility that a "screening layer" of charge at the cloud-air boundary contributed to the corona profile from two of these flights is presented.