Abstract/Summary

Electrostatic effects on clouds were speculated about by Luke Howard, but not directly investigated experimentally until the manned balloon flights of James Glaisher in the mid-nineteenth century. Recent balloon measurements in both hemispheres have investigated the electrical properties of extensive layer clouds, using modified radiosondes. On average, a small amount of charge is found to be associated with the upper and lower cloud boundaries of layer clouds. Whether there are significant consequences for the cloud microphysics continues to be investigated.