Caustic activation of rain showers
Disordered Systems and Neural Networks
2009-11-11 v1 Statistical Mechanics
Abstract
We show quantitatively how the collision rate of droplets of visible moisture in turbulent air increases very abruptly as the intensity of the turbulence passes a threshold, due to the formation of fold caustics in their velocity field. The formation of caustics is an activated process, in which a measure of the intensity of the turbulence, termed the Stokes number St, is analogous to temperature in a chemical reaction: the rate of collision contains a factor exp(-C/St). Our results are relevant to the long-standing problem of explaining the rapid onset of rainfall from convecting clouds. Our theory does not involve spatial clustering of particles.
Keywords
Cite
@article{arxiv.cond-mat/0604166,
title = {Caustic activation of rain showers},
author = {Michael Wilkinson and Bernhard Mehlig and Vlad Bezuglyy},
journal= {arXiv preprint arXiv:cond-mat/0604166},
year = {2009}
}
Comments
4 pages, 3 figures