The plasma characteristics of a lightning discharge channel are reviewed.The spectrum of the natural lighting is investigated by employing the slit-less spectrograph.It is found that the spectrurm characteristics are closely related to the intensity of the lightning discharge.The lines in the lightning spectrum are classified into essential lines and characteristic lines, according to the characteristics of lightning spectra with different intensities.The characteristics of the lightning channel and the radiation of the lighting plasma are analyzed in the visible and infrared regions.It is shown that, the visible spectrum of lightning is determined by the radiation generated from the early stage to the development of lightning, while the near-infrared spectrum is determined by the radiation generated after current of lightning reaches the peak.The c ahaunel temperature and the electron density are calculated using the information obtained from the lightning spectrun.Both the temperature and the density decrease with the increasing length of lightning channel.Moreover, X-rays and neutrons are produced in the process of lighting mainly due to the pinch effects.
lightning discharge plasma lightning spectra discharge channel return stroke channel temperature electron density
ZHANG Huaming YUAN Ping ZHANG Yijun WAN Jianjie OUYANG Yuhua WANG Dongfang
Thunder Prevention and Observation Center of Shanxi Province, Taiyuan 030002, China College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou 730070, China Laboratory of Lightning Physics and Protection Engineering, Chinese Academy of Meteorological Scienc School of Mathematics and Physics, Lanzhou Jiaotong University, Lanzhou 730070, China Laboratory for Middle Atmosphere and Global Environment Observation, Institute of Atmospheric Physic