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.

MOVES IV. Modelling the influence of stellar XUV-flux, cosmic rays, and stellar energetic particles on the atmospheric composition of the hot Jupiter HD 189733b

“…Such particle settling leads to the build-up of a local electric field in the cloud, and if the field is large enough, a lightning strike will occur (Helling et al 2011a,b;. In an Earth-like atmosphere, a lightning strike produces an approximately 30 000 K hot plasma channel which only exists for a few seconds but has a strong influence on the chemistry in the surrounding atmosphere (An et al 2019). The detailed effect of lightning on the atmospheric chemistry will be the focus of future studies.…”

Vertical Temperature Profile of Natural Lightning Return Strokes Derived From Optical Spectra

“…Not only are these instruments very sensitive allowing dimly lit features to be observed, but the whole lightning channel can also be recorded while the spectrum is time‐resolved with high resolution. These past studies have analyzed stepped leaders (Cen et al., 2018; Chang et al., 2017; Harley et al., 2020; Warner et al., 2011), dart leaders (Cen et al., 2015; Chang et al., 2017; Walker & Christian, 2017), and return strokes from natural and triggered lightning (An et al., 2019; Qu et al., 2011; Walker & Christian, 2017, 2019).…”

“…They also found the total intensity of the emission spectrum was proportional to the amplitude of the electric field change and the energy transmission in a return stroke. Using a similar experimental setup, An et al (2019) used NII and OI lines to calculate the return stroke temperature along the radial direction of a small channel segment, and found it decreased from around 30,000 K at the channel core to around 500 K at a radial distance of approximately 10 cm. Walker and Christian (2019) used a high-speed CMOS camera with a grism to record the spectrum from 400 to 900 nm of triggered lightning return strokes.…”

Lightning Detection and Imaging Based on VHF Radar Interferometry

“…A high speed video camera (HSV) is the most direct way to study the lightning discharge channels by filming luminous lightning channels operating at high frame rates up to 30 Kfps [6][7][8][9][10]. Important information of lightning properties, e.g., the speed of leader propagation and the two-dimensional (2D) structure of lightning channels, can be derived based on the experiment using HSV and electrostatic field sensor [7,10].…”

“…Important information of lightning properties, e.g., the speed of leader propagation and the two-dimensional (2D) structure of lightning channels, can be derived based on the experiment using HSV and electrostatic field sensor [7,10]. Moreover, the configuration of HSV and transmission grating can be implemented to set up the spectral recording system in order to measure the temperature and radius of lightning channel [8].…”