Laboratory simulation of transient light events of the middle atmosphere under conditions of apokamp discharge (review)
E.A. Sosnin1,2, V.A. Panarin1, V.S. Skakun1, D.V. Beloplotov1, D.A. Sorokin1,2
1High Current Electronics Institute of the Siberian Branch of the RAS, Tomsk, Russia
2National Research Tomsk State University, Tomsk, Russia
Keywords: apokamp discharge, Venus, thundercloud, blue jet, giant jet, positive streamer, starter, transient luminous event
Abstract
Discharge phenomena in the Earth’s middle atmosphere are the source of the corresponding transient light events (transients): so-called starters, blue and giant jets. There are no direct methods for measuring the parameters of these transients; therefore, remote sensing methods, theoretical modeling, and experimental measurements of laboratory discharge parameters, which are analogues of natural phenomena, are used. The work reviews the results of laboratory simulation of transients in conditions of apokamp discharge from 2020 to the present. The energy threshold for triggering transients has been experimentally revealed: the maxima of energy release and electroluminescence in the UVB range in an apokamp discharge in air are attained in the pressure range from 70 to 100 torr, which approximately corresponds to the altitudes of transient formation at the troposphere - stratosphere interface (12-18 km). A similar criterion obtained by igniting an apokamp discharge in carbon dioxide predicts the altitudes where analogues of transients are to be observed in the atmosphere of Venus (70-75 km). Recording the propagation dynamics of plasma plumes of an apokamp discharge with nanosecond resolution confirms these conclusions, and, moreover, allows us to formulate a new hypothesis: the type of transient of the middle atmosphere starting from the dome of a thundercloud depends on the intra-cloud discharges and the ratio of the positive charge of the dome top and the negative charge of the outer layer. It is noted that the streamer head of an atmospheric transient should have a complex luminescence structure. The results can be used for refining models of transients of the middle atmosphere and choosing optical instruments for their observations.
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