Inference of charge transfer from lightning flashes in South Africa

Tasman, Jesse Dean
Tasman, Jesse Dean
Journal Title
Journal ISSN
Volume Title
The objective of this study is to determine the quantity of charge transferred, in Coulombs, during the continuing current phase of natural cloud-to-ground (CG) lightning flashes over an area in Johannesburg, South Africa. Continuing current is responsible for most thermal related lightning damages such as destruction of property, electrical fires and physical human trauma. The mitigation of lightningrelated risks can be better managed through improved measurement methods of naturally occurring lightning. The application of a point-charge model used to infer charge transfer from changing electric field measurements is detailed. A flatplate antenna with an integrator is set up to record the changing electric fields from lightning flashes. These measurements, along with high-speed video footage to determine continuing current durations, are processed and charge transfer quantities are inferred. From 34 negative lightning strokes with long continuing current (i.e. > 40 ms), the quantity of charge transfer ranges from 0.3 C to 145.5 C and has a mean quantity of 18.3 C. For the 5 recorded positive strokes, the quantity of charge transfer ranges from 3.7 C to 66.6 C
A dissertation submitted in fulfillment of the requirements to the Faculty of Science, University of the Witwatersrand, Johannesburg, for the degree of Master of Science in the School of Electrical and Information Engineering, June 2019
Tasman, Jesse Dean, (2019). Inference of charge transfer from lightning flashes in South Africa, University of the Witwatersrand,