Thunderstorms are responsible for the negative charge on the Earth and the corresponding positive charge on the atmosphere.
Franklin, in his risky experiment, noted that thunder clouds are mainly charged negatively, but are sometimes charged positively.
How thunderstorms are able to separate charges and to develop an electric field leading to lightning is an ongoing area of research in the cloud physics laboratory in the university.
Our new 10 metre tall cloud chamber allows us to examine charge transfers between colliding ice particles down to -50°. We can simulate cloud conditions in supercooled regions of clouds, where most of the electrification occurs, all the way up to cirrus anvils, where recent research has indicated that charge transfer continues.
Airborne studies with instrumented aircraft, together with new multi-station ground receivers, have revealed the cloud charge structure via the progress of lightning discharges through the clouds.
Coffee will be served from 18:00, before the start of the presentations and the talk will start at 18:30.