Lightning and its radio emission


  • J. B. Smyth,

  • D. C. Smyth


An exact solution of Maxwell's equations is presented which describes adequately for the first time the many observed characteristics of the lightning discharge. These include: the source of the field required to develop the discharge channel; the leader stepping with pause time between steps which continue along different directions; the large diameter halo appearance of the leader and the small diameter hot arc return stroke; the current rise time in the channel. The solution provides the electromagnetic properties (inductance, capacitance, impedance) required to describe in detail the characteristics of the radio emissions: the spatial distribution of the radio field including its relative intensity and polarization; time duration of the radio signal with aspect angle; the energy radiated by the process. The solution provides a basis for designing meaningful experiments to establish relationships between observables essential in isolating the important characteristics required for a more complete description of the nature of lightning.