论文标题
量化降雨的幸运液滴模型
Quantifying the lucky droplet model for rainfall
论文作者
论文摘要
很难解释无冰云的降雨，因为雨水发作的时间尺度比显微镜水滴之间碰撞的平均时间短。有人提出，雨滴是由非常罕见的“幸运”液滴产生的，与第一次碰撞的平均时间相比，在时间尺度上发生了大量的碰撞。这项工作使用大偏差理论来开发雨水淋浴发作时间尺度的估计，这是碰撞速率系数的函数。 讨论了变成雨滴的快速生长液滴的生长历史。结果表明，无论典型液滴的平均时间如何随碰撞数量的函数而变化，他们的前几个碰撞总是在时间上大约相等的时间间隔。
It is difficult to explain rainfall from ice-free clouds, because the timescale for the onset of rain showers is shorter than the mean time for collisions between microscopic water droplets. It has been suggested that raindrops are produced from very rare ' lucky' droplets, which undergo a large number of collisions on a timescale which is short compared to the mean time for a the first collision. This work uses large deviation theory to develop estimates for the timescale for the onset of a rain shower, as a function of the collision rate coefficients. The growth history of the fast-growing droplets which do become raindrops is discussed. It is shown that their first few collisions are always approximately equally spaced in time, regardless of how the mean time for typical droplets varies as a function of the number of collisions.
