Recording range of a lightning-flash counter

The recording range of a simple electrostatic-field-detecting lightning-flash counter in a subtropical climate has been investigated near Brisbane (lat. 27°S, long. 153°E). Supplementary observations were made near Darwin (lat. 12°S, long. 131 °E). The tests were carried out using a transistorised form of the lightning-flash counter recommended by the Conférence Internationale des Grands Réseaux Électriques (CIGRÉ). The counter has been observed to respond to both ground and cloud flashes, so that, for ground-flash-density calculations, two range values are required, together with a procedure for correcting for the unwanted response to cloud flashes. Previous estimates of the ranges of similar counters are reviewed. The field tests described indicate ranges considerably larger than those estimated from temperate-climate observations, but are in good agreement with the effective ranges predicted theoretically from a study of the characteristics of the counter and of the distributions of electrostatic-field changes in south-east Queensland; namely, 30km for ground flashes and 20km for cloud flashes.