The role of turbulence in thunderstorm, snowstorm, and dust storm electrification

Abstract

In this paper the contribution of turbulence into the electrification of thunderstorms, snowstorms, and dust storms is investigated for the first time. A model of large‐scale electric field generation in a weakly conducting medium, containing two types of particles charging by collisions, is used. Thunderstorm and snowstorm electrification are considered in detail in this paper; dust storm electrification is also considered, despite being substantially different from the two other cases, to demonstrate the universality of the proposed method. A comparison of the results with the experimental data for thunderstorms, blizzards, and dust storms is carried out. It is found that the situation is notably different for inductive and noninductive charge separations. For inductive charge separation there is a range of thunderstorm and snowstorm parameters (conductivity and the particle radii being the most important factors) for which the electric field grows exponentially with time. This effect can make the inductive mechanism dominant near the breakdown field in turbulent zones of thunderclouds. For noninductive (or triboelectric) charge separation caused by intense velocity fluctuations, the electric field strength grows only linearly with time. The most substantial effect of turbulence on noninductive charging is expected to occur in snowstorms and dust storms, whereas noninductive turbulent charging has a little impact on the thunderstorm electrification.

A Simple μ-PTV Setup to Estimate Single-Particle Charge of Triboelectrically Charged Particles

“…Nevertheless, triboelectric charging is an exciting but so far not completely understood phenomenon. It has been investigated in many fields of research, such as contact electrification in dust devils (Farrell, 2004; Mareev and Dementyeva, 2017), in clouds after volcanic eruptions (Anderson et al, 1965; Mather and Harrison, 2006), in the formation of planets (Yair et al, 2008; Wang et al, 2017), and in almost every application dealing with fine and dry powders. Commonly, triboelectric charging is seen as a problem in industrial applications if particles are to be moved because charged particles tend to agglomerate and adhere on surfaces (Wong et al, 2015).…”

Toward a Realistic Representation of Global Electric Circuit Generators in Models of Atmospheric Dynamics

“…One natural idea is to assume a linear dependence between the charge separation current density and CAPE: where is the characteristic value of CAPE in intense convective systems. Another option is to use the quadratic formula the reasoning behind this assumption is that the charge separation current is proportional to both the relative velocity of colliding particles and the charge transferred in each collision, which, in its turn, is also related to the relative velocity by a power law with the exponent about 2 or 3 (at least in the case of noninductive charging; see Mareev & Dementyeva, ; Norville et al, ); thus, the charging current is proportional to the third or fourth power of the relative velocity, or to or (since CAPE is approximately proportional to the square of this velocity; see Williams & Stanfill, ). Figure e shows the diurnal variation of the IP computed with and ; it is clear that both these curves are similar in shape to our basic curve but reach their main maxima earlier.…”

A Distinct Negative Leader Propagation Mode

“…The fact that at the end of the IRNL mode a large multitude of negative leaders have been created supports the picture of a small region with a very high space charge. The dense charge pocket is probably created by a local turbulence [26], with a typical size of order 5 km 2 . This dense space charge leads to a larger than usual amount of charge at its tip and an increased propagation velocity, both contributing to a strongly enhanced VHF power and strong broadband pulses when the propagation is in the vertical direction during the IRNL mode.…”