Evolution of Discharge Characteristics Along the Positive Cloud‐To‐Ground Lightning Channel

Abstract

Two positive cloud‐to‐ground lightning spectra have been captured by a slit‐less spectrograph. In combination with the synchronous electric field change waveshape, the discharge characteristics along the channel have been investigated. The results show that the total intensity of ionic lines in spectra and the electrical conductivity increase with the increase of channel height. According to the positive correlation between the total intensity of ionic lines and the discharge current, it is found that the current intensity of downward positive cloud‐to‐ground lightning increases with the increase of channel height. Comparing it with the reported current attenuation along the channel of downward negative lightning, it is deduced that the increasing or decreasing of the current along the discharge channel is likely to be related to the current direction.

First Experimental Verification of Opacity for the Lightning Near‐Infrared Spectrum

“…Due to the randomness of natural CG lightning occurrences and observation conditions as well as discharge environmental restrictions, NI (3) and NI (2) cannot be distinguished well in previously observed spectra of natural CG lightning (An et al, 2021;Liu et al, 2019;Wan et al, 2021;Wang, Yuan et al, 2016. By focusing on lightning discharge processes on tall structures, we obtained spectral data with better wavelength resolution.…”