Characterization of Close Electric Field Waveforms From Triggered Lightning

In this article, we analyzed the characteristic parameters of close vertical electric field waveforms from triggered lightning at 58 and 90 m obtained at Conghua, Guangzhou, in the summer of 2019. A total of 11 characteristic parameters were defined, including leader electric field peak [kV/m] (
E_L
), return stroke electric field change [kV/m] (
E
_RS
), zero-to-peak rise time [
μ
s] (
T
₁
), 10-to-90% rise time [
μ
s] (
T
₂
), half-peak width [
μ
s] (
T
₃
), zero-crossing time [
μ
s] (
T
₄
), slow-front duration [μs] (
T
₅
), opposite polarity overshoot duration [
μ
s] (
T
₆
), fast-transition 10-to-90% rise time [
μ
s] (
T
₇
), opposite polarity overshoot ratio [%] (
E
_OS
/
E_L
), and slow-front magnitude relative to peak [%] (
E_S
/
E_L
). The arithmetic mean, geometric mean, and standard deviation of each parameter were counted. Data comparison results at 58 and 90 m show that
T
₁
–
T
₇
at 90 m were larger than those at 58 m.
E_L
and
E
_RS
at 90 m were both positively correlated with the peak current [kA] (
I_P
). The influence of distance on this correlation was also analyzed. The half-peak width of the current waveform was inversely proportional to that of the electric field waveform.