Por: R. Giles Harrison

Department of Meteorology, University of Reading, UK

Data: 19 de Junho 2013

Hora: 14:30
Local: Anfiteatro 1 - CLAV

Abstract:
Not long after Benjamin Franklin’s iconic studies, an atmospheric electric field was discovered in “fair weather” regions, well away from thunderstorms. The fair weather field’s origin was ultimately explained through the global circuit model of the Scottish atmospheric physicist C.T.R. Wilson, who won the Nobel Prize for inventing the cloud chamber. In Wilson’s model, charge exchanged by disturbed weather electrifies the ionosphere, and returns via a small vertical current density in fair weather regions.  New insights into the relevance of fair weather atmospheric electricity to terrestrial and planetary atmospheres are now emerging through novel instrumentation and measurements, particularly in close relationships between energetic particles, atmospheric electricity, atmospheric aerosol and ions. For example, the atmospheric electric field is highly sensitive to energetic particles, surface ionisation release associated with earthquakes, and there may also be a role of the  global circuit’s current density in cloud formation.