In addition to its many benign effects, lightning is one of Mother Nature’s serious threats to life and property. Extensive measurements in the field and well designed rocket experiments have enriched our knowledge of lightning. However, there are many mysteries of lightning yet to be unravelled. One such aspect is the possible influence of soil resistivity on the current amplitude of a lightning stroke. A unique self-consistent return lightning stroke model developed in our group, amongst others, considers the ionisation in soil (Figure (a)) and frequency-dependent properties. Using this model, it has been shown, for the first time, that the current amplitude of a lightning stroke can diminish by as much as 45% in highly resistive soils (Figure (b)). This is perhaps a part of Nature’s design to counter its own vagaries.
Reference:
Rupam Pal and Udaya Kumar, “Modeling of Return-Stroke Current Evolution Over a Realistic Ground”, IEEE Transactions on Electromagnetic Compatibility, 09 April 2021, DOI: 10.1109/TEMC.2021.3066839
