Size distribution of raindrops

Abstract

, collisional disk break-up that results from the fragmentation of a large drop originated by the near head-on collision of two drops is well documented 10 . #e transient shape of the large drop evolves to form a 'bag' a!er collision, and then a 'disk' before breaking to yield a large number of small drops. VB speculate that collisional break-up is unlikely. However, the mean free path for drop-drop collision is of the same order of magnitude as the average distance a drop has to fall before experiencing spontaneous break-up 3 . Furthermore, spontaneous break-up occurs only once for each (rare) large drop, whereas many interactions can occur among a wide size range of small drops in their downward trajectory. Indeed, surveys of laboratory experiments under free-fall conditions 7-9 indicate that collisional disk break-up is responsible for up to 20% of all break-up events 7,8