We propose a small-scale transport model of the electric-discharge tree formation and analyze its implementation for a characteristic case of the thundercloud conditions. The following innovative features of the model can be emphasized: no connection to the spatial grid, high spatiotemporal resolution, and allowance for the asymmetry of the development of the positive and negative streamers and the time evolution of the discharge-channel parameters. The criterion of the streamer-to-leader transition, which is used in this work, is formulated in terms of the channel temperature and is based on the well-known mechanism of ionization-overheating instability, which is universal for the spark discharge. Within the framework of the described approach, a heated well-conducting leader channel is formed by combining the currents of tens of thousands of streamers, so that each of them initially has f negligible conductivity and a temperature that does not differ from the ambient temperature. The model bileader tree has electrodynamic characteristics that are intermediate between those known for the laboratory long spark and the developed lightning, which is expected for an “immature” lightning leader. The morphology and electrical parameters of the calculated discharge tree of the incipient model lightning leader agree with the modern data on the lightning-discharge development.

中文翻译：

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雷暴云中火花放电的自组织传输模型

我们提出了放电树形成的小规模传输模型，并分析了其在雷云条件的特征情况下的实现。可以强调该模型的以下创新特点：与空间网格无关，时空分辨率高，并允许正负流光发展的不对称性和放电通道参数的时间演变。在这项工作中使用的流注到引线转变的标准是根据通道温度制定的，并且基于众所周知的电离过热不稳定性机制，这对于火花放电是普遍的。在所述方法的框架内，由数以万计的流光流汇合形成加热良好的先导通道，使每条流光最初具有可忽略不计的电导率和与环境温度无差异的温度。模型双头树具有介于已知的实验室长火花和发展的闪电之间的电动力学特性，这是“不成熟”的闪电头的预期。计算出的初始模型雷电先导放电树的形态和电气参数与现代雷电发展数据一致。模型双头树具有介于已知的实验室长火花和发展的闪电之间的电动力学特性，这是“不成熟”的闪电头的预期。计算出的初始模型雷电先导放电树的形态和电气参数与现代雷电发展数据一致。模型双头树具有介于已知的实验室长火花和发展的闪电之间的电动力学特性，这是“不成熟”的闪电头的预期。计算出的初始模型雷电先导放电树的形态和电气参数与现代雷电发展数据一致。