Background and Objectives

Background and Objectives:

The research in lightning is as old as the research in electricity. In 1750 Benjamin Franklin suggested an experiment that later proved lightning is an electrical discharge. Two years later the experiment was first successfully performed in France, followed by in England and Belgium. In July 1753, G.W. Richmann, a Swedish physicist (born in Estonia) working in Russia was killed by a direct lightning strike, while performing Franklin’s experiment. The Franklin rod for protecting buildings from the effects of lightning strike was one of the first electrical devices. From the very beginning lightning research was interdisciplinary, attracting scientists from different branches of science. It was C.T.R. Wilson, recipient of the Nobel Prize for Physics in 1927 for the invention of the cloud chamber, who first determined the amount of electrical charges involved in lightning and thunderstorms by remote electric field measurement.

Since those early days research on lightning has come a long way, but still a long way to go. The main objective of the COST Action P18 is to increase the knowledge of the physics of the lightning discharge and of its effects on natural and man-made systems. This will include the following sub-objectives, but not limited to them.

To understand and model the different physical processes in the lightning channel.
To understand and model the lightning attachment to objects.
Measurement of characteristics of lightning flashes in Europe and an establishment of a data bank on the lightning parameters, including a databank on the characteristics of the electromagnetic radiation of lightning from ELF to gamma rays.
Develop models for the inverse source problem in lightning, that is, inferring the characteristics of the processes in the lightning channel from remote measurements of the electromagnetic waves associated with lightning.
To understand the mechanism of the production of the trace gas species in the atmosphere by the hot plasma channel and corona in lightning discharge.
To understand the connection between the particular characteristics of lightning flashes and the associated observation of luminous events in the mesosphere and the lower ionosphere.

Fulfilling the above objectives would increase our knowledge of the most important scientific issues in lightning research, namely, the phenomenology of processes in the lightning flash, lightning initiation in thunderclouds, mechanism of lightning stepped leader and dart leader, mechanism of lightning attachment to objects, mechanism of lightning return stroke, mechanism of X-rays and gamma-rays emission associated with lightning, mechanism of ball lightning, mechanism of trace gas species production by lightning, and the connection between lightning and upper luminous events in the atmosphere. In addition, increased knowledge of the physics of lightning would help several scientists and engineers in devising better strategies for protecting sensitive systems from the deleterious effects of lightning and to understand the impact of lightning on the chemistry of the atmosphere and on the global electric circuit.