A Comparison of Lightning Electromagnetic Fields with the Nuclear Electromagnetic Pulse in the Frequency Range 104-107 Hz

The electromagnetic fields produced by both direct lightning strikes and nearby lightning are compared with the nuclear electromagnetic pulse (NEMP) from an exoatmospheric burst. Model calculations indicate that, in the frequency range from 104 to near 107 Hz, the Fourier amplitude spectra of the return stroke magnetic fields near ground 1 m from an average lightning strike will exceed that of the NEMP. Nearby first return strokes at a range of about 50 m, if they are severe, produce electric-field spectra near ground which exceed that of the NEMP below about 106 Hz, while the spectra of average nearby first return strokes exceed that of the NEMP below about 3 x 105 Hz. Implications of these results for aircraft in flight are discussed.