Our studies have shown that the effect of metal vapors on the color of the discharge plasma is much greater in the case of a pulsed breakdown in a nonuniform electric field. This made it possible to compare with the color of various discharges occurring in the upper atmosphere (Figure 1 in the text of the article). Even with well-studied discharges, it is very difficult to obtain such results. Thus, during an arc discharge, although there is a strong evaporation of the electrodes and the ejection of particles of various sizes, the voltage across the gap is low and the discharge in metal vapors outside the high-temperature arc channel is practically absent. Under these conditions, broadband Planck radiation from the arc channel plasma is observed. In a glow discharge, the sputtering of the electrodes has a low rate, and the emission spectra of the plasma of such discharges contain atomic and molecular transitions of the gases used. In the investigated mode, metal vapors are produced and excited by a pulsed discharge.
Of course, metal vapors, nano- and micro-particles can affect the characteristics of the discharge. This is known from numerous studies of simpler and more understandable plasma objects such as glow discharge and arc. Similar studies and comparisons with known experimental data could be carried out on these objects. In this connection, the use of high-voltage pulse discharges is not justified. The authors draw an analogy with the formation of sprites, then, in my opinion, the study would be more suitable for another journal related, for example, atmospheric research.