Lightning activity in the UK

Total protection from lightning is not presently possible, however even if it was, it is likely that economic considerations would preclude universal application. The assessment of risk is therefore an essential element in the consideration of protection of any structure. The question of where, and how much, and what type of protection does not have an exact answer. The consequences of a strike need to be assessed and the costs of protection balanced against the cost of accepting the increased risk if protection is not installed. However, the risk cannot be evaluated without knowledge of the probability that a strike of a given strength will occur in the vicinity of the structure to be protected. This is the role of lightning location systems such as that operated by EA Technology. The author discusses the EA Technology lightning location system which uses radio direction finding techniques to locate lightning strikes as they occur. The system has been operated as a commercial service since 1989, providing both on-line information and historical information on lightning activity in the UK and Ireland. The isoceraunic level, ground stroke density, stroke strength, polarity and temporal variations are discussed.