1.4.1 Peak value of the lightning current

Lightning currents are impressed currents, in other words a lightning discharge can be considered to be an almost ideal current source. If an impressed electric current flows through conductive parts, a voltage drop across the part carrying the current occurs due to the amplitude of the current and the impedance of the conductive part carrying the current. In the simplest case, this relationship can be described using Ohm's law (Equation 1.4.1.1):