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Динамика изменения состава отрицательных ионов вокруг гидрометеоров в грозовом облаке
Recently, a new mechanism of the lightning discharge initiation in a thundercloud has been discussed.
It is based on a noise-induced kinetic transition, which consists of an increase in the concentration
of atmospheric ions in the intracloud environment under the impact of the stochastic electric field of charged
and polarized hydrometeors (drops, snowflakes, graupel, hail). The source of noise is electric field bursts that
occur during collisions or near collisions of hydrometeors and are accompanied by the streamerless corona
discharge ignition. The key point in this scenario is the relay process, in which new ionization centers, when
the corona discharge is ignited, arise against the background of spots of negative ion charge remaining from
the spreading old centers. This leads to a gradual increase in the concentration of negative ions, which could
serve as a source of free electrons with a new increase in the electric field. In this work, we theoretically study
the possibility of electron detachment from negative ions formed in a streamerless negative corona near
hydrometeors under thundercloud conditions. It is shown that in this case the dominant negative ions near
corona hydrometeors are О2-(Н2О)k and O4- cluster ions. It follows from the calculations that when a high
electric field is applied, electrons are released not via direct detachment from cluster ions, but in multi-steps
in a sequence reverse to that observed without a field during the formation of cluster ions. As a result, to
detach electrons from ions like О2-(Н2О)k, fairly moderate pre-breakdown reduced electric fields are required
at a level of 65 Td.