Electric and Magnetic Fields Predicted by Different Electromagnetic Models of the Lightning Return Stroke Versus Measured Fields

We have compared current distributions along a vertical lightning channel above flat ground excited at its bottom by a lumped current source and electromagnetic field waveforms at different distances from the channel, calculated using the finite-difference time-domain method, for different lightning return-stroke electromagnetic models. The channel representations considered include a vertical, perfectly conducting wire surrounded by air (type 1), a vertical wire in air loaded by additional distributed series inductance L = 2.5 muH/m and distributed series resistance R = 0.5 Omega/m (type 2), a vertical, perfectly conducting wire embedded in dielectric of relative permittivity epsivr = 4 that occupies the entire half space (type 3), a vertical, perfectly conducting wire embedded in a 10-m-radius dielectric cylinder of epsivr = 400 surrounded by air (type 4), and a vertical wire embedded in a 10-m-radius cylinder of epsivr = 5 and relative permeability mur = 5 surrounded by air (type 5). For the type-1 model, the speed of the current wave propagating along the lightning channel is essentially equal to the speed of light, v = c. For type-2, type-3, and type-5 models, v = 0.5 c, and for the type-4 model, v = 0.7 c. Models of types 2 and 5 reproduce the maximum number of characteristic features of electric and magnetic field waveforms observed at distances ranging from 1 to 200 km from natural lightning and at distances ranging from tens to hundreds of meters from rocket-triggered lightning. Modifications of type-2 and type-5 models in which distributed channel resistance is not uniform can reproduce all five characteristic features. The influence of lossy ground with conductivity as low as 0.1 mS/m on vertical electric and azimuthal magnetic fields within about d = 5 km is not significant. The initial peak of vertical electric field at d = 50 km for sigma = 0.1 mS/m is 20% smaller than that for sigma = infin. The 10%-90% rise time at d = 50 km is 5 mus for sigma = 0.1 mS/m versus 1 mus for sigma = infin.

[1]  Vladimir A. Rakov,et al.  Luminosity characteristics of dart leaders and return strokes in natural lightning , 1997 .

[2]  K. Yee.  Numerical solution of initial boundary value problems involving maxwell's equations in isotropic media , 1966 .

[3]  Vladimir A. Rakov,et al.  Lightning Return Stroke Speed , 2007 .

[4]  Y. Baba,et al.  Reproduction of lightning electromagnetic field waveforms by engineering model of return stroke , 2004, IEEE Transactions on Electromagnetic Compatibility.

[5]  Jeremy A. Landt,et al.  Three Dimensional Time Domain Modelling of Lightning , 1987, IEEE Transactions on Power Delivery.

[6]  V. P. Idone,et al.  Lightning return stroke velocities in the thunderstorm research international program (TRIP) , 1982 .

[7]  V. Rakov,et al.  Electromagnetic Fields at the Top of a Tall Building Associated With Nearby Lightning Return Strokes , 2007, IEEE Transactions on Electromagnetic Compatibility.

[8]  Y. Baba,et al.  Applications of Electromagnetic Models of the Lightning Return Stroke , 2008, IEEE Transactions on Power Delivery.

[9]  Martin A. Uman,et al.  Return stroke transmission line model for stroke speed near and equal that of light , 2001 .

[10]  Gerhard Diendorfer,et al.  Influence of channel base current and varying return stroke speed on the calculated fields of three important return stroke models , 1991 .

[11]  M. Uman,et al.  Lightning return stroke current models with specified channel‐base current: A review and comparison , 1990 .

[12]  Vladimir A. Rakov,et al.  The close lightning electromagnetic environment: Dart‐leader electric field change versus distance , 2001 .

[13]  V. Cooray,et al.  Pulse Propagation Along Transmission Lines in the Presence of Corona and Their Implication to Lightning Return Strokes , 2008, IEEE Transactions on Antennas and Propagation.

[14]  E. K. Miller,et al.  An integro-differential equation technique for the time-domain analysis of thin-wire structures. II. Numerical results , 1973 .

[15]  Y. Baba,et al.  Representation of an Arbitrary-Radius Wire for FDTD Calculations in the 2-D Cylindrical Coordinate System , 2008, IEEE Transactions on Electromagnetic Compatibility.

[16]  V. Rakov,et al.  Parameters of triggered-lightning flashes in Florida and Alabama , 1993 .

[17]  Zhenpeng Liao,et al.  A TRANSMITTING BOUNDARY FOR TRANSIENT WAVE ANALYSES , 1984 .

[18]  Vladimir A. Rakov,et al.  Review and evaluation of lightning return stroke models including some aspects of their application , 1998 .

[19]  Vladimir A. Rakov,et al.  A new lightning return stroke model based on antenna theory , 2000 .

[20]  Roger F. Harrington,et al.  Field computation by moment methods , 1968 .

[21]  S.H.H. Sadeghi,et al.  On Representation of Lightning Return Stroke as a Lossy Monopole Antenna With Inductive Loading , 2008, IEEE Transactions on Electromagnetic Compatibility.

[22]  Y. Baba,et al.  On the mechanism of attenuation of current waves propagating along a vertical perfectly conducting wire above ground: application to lightning , 2005, IEEE Transactions on Electromagnetic Compatibility.

[23]  Vladimir A. Rakov,et al.  Some inferences on the propagation mechanisms of dart leaders , 1998 .

[24]  Yoshihiro Baba,et al.  Electromagnetic models of the lightning return stroke , 2007 .

[25]  Silverio Visacro,et al.  A distributed‐circuit return‐stroke model allowing time and height parameter variation to match lightning electromagnetic field waveform signatures , 2005 .

[26]  V. Rakov,et al.  On the Relationship Between the Signature of Close Electric Field and the Equivalent Corona Current in Lightning Return Stroke Models , 2008, IEEE Transactions on Electromagnetic Compatibility.

[27]  Tomomi Narita,et al.  Simulation of electromagnetic field in lightning to tall tower , 1999 .

[28]  Vladimir A. Rakov,et al.  Observed one‐dimensional return stroke propagation speeds in the bottom 170 m of a rocket‐triggered lightning channel , 2004 .

[29]  M. Plooster,et al.  Numerical Model of the Return Stroke of the Lightning Discharge , 1971 .

[30]  J. R. Grant,et al.  Characterization of Lightning Return Stroke Electric and Magnetic Fields From Simultaneous Two- Station Measurements (Paper 9C0949) , 1979 .