Stratospheric electric field and conductivity measurements over electrified convective clouds in the South American region

Abstract

In this work, stratospheric dc electric fields and conductivity measurements, associated with electrified convective clouds identified by satellite infrared imagery, are presented. These measurements were obtained at an altitude of 26 km by a balloon‐borne double‐probe detector, launched from Cachoeira Paulista (geographic coordinates 23°40′S, 45°W) on April 2, 1980. The electric fields are found to correspond to electrified convective clouds with charges of the order of a few coulombs. The conductivity measurements show variations by over a factor of 2 around the average value of 4 × 10−12 mho/m. Such variations, which merit more investigation, did not show an apparent relation with the simultaneous electric field measurements. Using the vertical electric field and conductivity measurements, a current density is also estimated. Furthermore, a detailed original discussion on conductivity measurements in the atmosphere as well as a suggestion for estimating distances from the detector to the cloud, using the ratio between the magnitudes of the measured vertical and horizontal electric fields, is included.