Elecrtic Fields from Lightning Strokes of Complicated Geometry

Time domain electric fields are addressed in the neutral atmosphere that originate from the lightning strokes of a complicated structure of lightning channel. A model of the return stroke is used with traditional current waveform. The current wave moves along the channel with an exponentially decaying velocity. Static, induction and radiation fields are treated for the following cases: (1) powerful vertical return stroke (2) positive stroke that initiates from the ground or from the cloud top (3) 'broken' discharge (4) 'staircase' discharge, and (5) 'spider' stroke. Electric multiple pulses appear owing to current wave movement and twisting of the lightning channel. Vector of the electric field acquires transient vertical, inward/outward and sideways components, which 'scan' the sky. Atmosphere disturbances around the thunderstorm may cause fluctuations in the air density and temperature, which assist in modification of the middle atmosphere.