Generally conduction, such as the conduction of a thunderstorm cloud, involves the presence of a conducting channel through which the current flows. By default, it is considered that if there is no such channel in a non-conducting medium that “shortens” a certain potential difference, then there can be no current. However, a group of Nizhny Novgorod scientists from the Institute of Applied Physics of the Russian Academy of Sciences and the Volga Medical Research University proposed and numerically studied an alternative charge transfer mechanism that can develop even in the absence of a large-scale conducting channel scale It depends on the stochastic dynamics of a system consisting of a relatively small number of constantly emerging and decaying conductive plasma formations.
Although the scattered small clusters do not come into contact with each other in the instantaneous 3D images of the system, they turn out to be connected in a 4D space-time continuum. This charge transport mechanism was called a “relay”. Just as runners pass a baton to each other, space charges (analogous to a baton), once separated by already damped conducting structures (analogous to a passing runner), are “picked up” and transferred by newly emerging clusters (similar to an athlete). receiving a cane).
To investigate the separation of point charges along the direction of an external electric field as a result of the stochastic dynamics of a system of ideally conducting clusters, scientists have developed a special numerical model. It was found that the described charge transfer mechanism is directly related to the problem of lightning initiation, which is the main mystery of the physics of atmospheric electricity.
In this case, the relay-race charge transport manifests itself in two successive modes. In the early, long, spatially homogeneous stages, charge is transferred due to the recently discovered regions of higher ionic conductivity (see Nature) that are constantly emerging and decaying. They are ion dots with characteristic dimensions of 0.1–1 m and a lifetime of 1–10 s, which form due to corona discharges that accompany collisions or the convergence of water and ice particles.
Since the conductivity of these ion spots is several orders of magnitude higher than the conductivity of the air inside a thundercloud, they have time to polarize during their existence, which allows them to be considered as conductors placed inside a dielectric. The dynamics of regions of increased ionic conductivity create electric field fluctuations with ever-increasing amplitudes, which ultimately lead to the onset of first streamers (a weakly conductive, non-self-sustaining form of spark discharge) and then leaders (a -sustained form of of a spark discharge with a well-conducting channel).
In the later streamer/leader stage, the charge transfer efficiency of the relay race increases dramatically due to the fact that streamers and leaders (unlike ion dots unable to self-propagate) are able to grow and fuse with each other as a result of electrostatics . attraction (Fig. 1). The unification of self-organized discharge systems that accelerate in time eventually ends with the formation of a dominant cluster. It includes the vast majority of system elements, overlaps the intracloud zone of a strong electric field, and can be associated with a self-sustaining lightning “seed.”
The article was published in Scientific Reports.
rice one. Lightning initiation process from the point of view of cluster-cluster aggregation. The spatially homogeneous relay race charge transfer mode based on weakly conducting transmission channels (a) gradually flows in the stage when the right conduction segments (red leading channels) merge rapidly along the direction of the external field, forming a channel of a well-polarized self. -support lightning leader (d). The emergence of a dominant, “absorbing” cluster
smaller elements and “shorten” the zone of a strong intracloud field, marks the transition
from relay driving to ordinary driving.