In natural clouds, water droplets grow by condensation in a supersaturated environment. Under subsaturated conditions, water droplets normally keep evaporating until they eventually disappear. In this article, we study the effect of corona discharge on water droplet growth under both supersaturated and subsaturated conditions. It is shown that the formation of mist visible to the naked eyes could be induced by direct current (dc) corona discharge under supersaturated conditions. Furthermore, we find that corona discharge could promote the growth of water droplets even under subsaturated conditions. Possible mechanisms are discussed, and the results suggest that the droplet growth enhancement is supported by the synergetic effects of droplet surface charge, external electric field, and ionic wind generated by the corona discharge.

中文翻译：

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空气中电晕放电引起的水滴生长

在自然云中，水滴在过饱和环境中通过凝结而生长。在不饱和条件下，水滴通常会不断蒸发，直到最终消失。在本文中，我们研究了过饱和和亚饱和条件下电晕放电对水滴生长的影响。结果表明，在过饱和条件下，直流电晕放电可以诱发肉眼可见的雾的形成。此外，我们发现即使在不饱和条件下，电晕放电也可以促进水滴的生长。讨论了可能的机制，结果表明液滴表面电荷、外部电场和电晕放电产生的离子风的协同效应支持液滴生长增强。