A model to represent negative and positive lightning first strokes with connecting leaders

Exponential approximation of the Heidler function for the reproduction of lightning current waveshapes

“…The most important improvement is that HF first time derivation for t = 0 is equal to zero and, consequently, does not have a discontinuity at the start. New analytical expressions for lightning current, which are an extension of HF, are introduced by other authors [11][12][13][14][15]. In paper [11], Nucci et al represent the current at the channel base of the subsequent return stroke by a combination of the HF with the current steepness factor n = 2 and the doubleexponential function.…”

Multiple pulses in dE/dt and the fine-structure of E during the onset of first return strokes in cloud-to-ocean lightning

“…During the time when there are both upward and downward propagating waves, the radiated field could be up to a factor of two larger than what would be radiated after the partial reflection (see, for example, Fig. 17 in Leteinturier et al (1990) and the discussion in Cooray et al (2004)). Fig.5), who excluded all Type B waveforms and some Type C waveforms from their analyses and then compared the peak dE/dt to the amplitude of the fast-transition in E (i.e., the slow front was omitted).…”

“…Large values of dI/dt will be produced whenever there is an abrupt onset (or termination) of any large current that flows during the breakdown of air, in response to a large potential difference. and Uman, 1998;2003, Chapter 12;and Cooray et al, 2004).…”

“…Three independent flush plate antennas mounted on the roof of a well-grounded metal trailer were used to measure the E, dE/dt, and RF signals produced by the lightning. The trailer housed the recording electronics and was parked about 45 m from the Atlantic Ocean so that any fields originating from lightning over the ocean would be measured with minimal distortions due to the effects of propagation over the ocean/land surface (Cooray and Ming, 1994;Cooray, 2003, Chapter 7;Cooray et al, 2004).…”

Transcranial stimulability of phosphenes by long lightning electromagnetic pulses

“…We first consider straight vertical lightning channels using a leader model with a typical value for the homogeneous charge distribution of q = 0.14 mC/m [16], and a current generation type model for the return stroke [20].…”