The Role of Diffusion in Closing Artifically Produced Holes in Clouds

Abstract

Hole closing by diffusion of water vapor and droplets is treated as a problem in classical diffusion theory with constant mixing coefficients. The results, for reasonable estimates of the variables involved, lead to closure times in the one-half to one hour range. However, the estimates of the appropriate diffusion coefficients are quite rough and it may be useful to employ cloud-dissipation techniques to estimate this variable. Further calculations show that to maintain a given area free of clouds for the maximum time possible, a hole whose width is 75?80% of the distance between the smallest useful hole and the maximum possible hole should be opened.