The radius and temperature distribution along radial direction of lightning plasma channel

Abstract

Based on various radiation components in the spectra of lightning return stroke processes, the temperature of the lightning channel is diagnosed by different methods. Combining with the synchronized electric field data and optical pictures of the lightning channel, the radii of the core current channel and the luminous channel are estimated. On the basis of the above mentioned facts, according to the heat conduction equation, the channel temperature distribution along the radial direction of the lightning return stroke channel is also achieved. The results from six lightning return strokes show that for the core current channel and luminous channel, the radii are in the range of 0.66–1.01 cm and 5.03–7.96 cm, respectively, and the corresponding channel temperatures are 27 300–30 300 K and 3300–5800 K, respectively. Within an average radius of around 1.76 cm, channel temperatures are above 20 000 K and fall sharply along the radial direction while gradually decline outside this range. The radii of the glowing edge with a temperature of around 500 K are first estimated, around 6.94–13.0 cm.