Estimation of channel characteristics of narrow bipolar events based on the transmission-line model

[1] Narrow bipolar event (NBE) is a distinct class of intracloud lightning discharge, which is associated with the strongest radio frequency emissions and produces typical narrow bipolar radiation field waveforms. On the basis of the transmission-line model, we introduce a direct technique to measure the time taken by the current front to propagate along the channel from distant radiation field pulses; the channel length of the NBE can then be estimated by multiplying this time by an assumed propagation speed. Our method involves integrating over the initial half cycle of narrow bipolar waveform of the NBE. The ratio of the integral result to the initial peak amplitude makes a good approximation to the time taken by the current front to travel along the channel, even though the current amplitude suffers heavy attenuation along the propagating channel. This method can be applied to all NBEs which produce narrow bipolar radiation field waveforms. Besides, if both the far radiation field and the near-electrostatic field measurements were available, one could combine the method here and that of Eack (2004) to obtain the channel length of the NBE.

[1]  X. Shao,et al.  Estimating lightning channel characteristics of positive narrow bipolar events using intrachannel current reflection signatures , 2007 .

[2]  M. Uman,et al.  Magnetic field of lightning return stroke , 1969 .

[3]  D. M. Le Vine,et al.  Comment on the transmission‐line model for computing radiation from lightning , 1992 .

[4]  William W. Hager,et al.  An analysis of errors in the location, current, and velocity of lightning , 1995 .

[5]  J. C. Willett,et al.  Submicrosecond field variations during the onset of first return strokes in cloud‐to‐ground lightning , 1996 .

[6]  Paul Krehbiel,et al.  Observations of VHF source powers radiated by lightning , 2001 .

[7]  J. C. Devenport,et al.  Satellite observations of transionospheric pulse pairs , 1995 .

[8]  R. Roussel-Dupre,et al.  Radio frequency emissions from a runaway electron avalanche model compared with intense, transient signals from thunderstorms , 2005 .

[9]  K. Zybin,et al.  Amplification and nonlinear modification of runaway breakdown , 2006 .

[10]  K. Eack.  Electrical characteristics of narrow bipolar events , 2004 .

[11]  D. E. Proctor,et al.  Lightning flashes with high origins , 1997 .

[12]  T. E. Light,et al.  Bimodal radio frequency pulse distribution of intracloud-lightning signals recorded by the FORTE satellite , 2003 .

[13]  David M. Le Vine,et al.  Sources of the strongest RF radiation from lightning , 1980 .

[14]  David A. Smith,et al.  A distinct class of isolated intracloud lightning discharges and their associated radio emissions , 1999 .

[15]  David Smith.  Compact Intracloud Discharges , 1998 .

[16]  J. C. Willett,et al.  Submicrosecond intercomparison of radiation fields and currents in triggered lightning return strokes based on the transmission-line model , 1989 .

[17]  Vladimir A. Rakov,et al.  Attachment process in rocket‐triggered lightning strokes , 1999 .

[18]  Richard E. Orville,et al.  Lightning leader characteristics in the Thunderstorm Research International Program (TRIP) , 1982 .

[19]  T. Marshall,et al.  Current propagation model for a narrow bipolar pulse , 2007 .

[20]  V. Rakov,et al.  Electromagnetic Pulses Produced by Bouncing-Wave-Type Lightning Discharges , 2009, IEEE Transactions on Electromagnetic Compatibility.

[21]  M. Uman,et al.  The electromagnetic radiation from a finite antenna , 1975 .

[22]  D. M. Suszcynsky,et al.  Narrow Bipolar Events as indicators of thunderstorm convective strength , 2003 .