The Problem of Artificial Control of Rainfall on the Globe

Abstract

: Different kinds and degrees of colloidal and thermodynamical instability of diverse systems of cloud-particles, partly leading to release of precipitation, are discussed, aiming at estimating the possible effect of “seeding” clouds artificially with ice-nuclei. — A low ratio v of supercooled cloud-droplets versus ice-crystals (v ≤ 1) would ensure very rapid glaciation of the cloud, but no precipitation release and no substantial improvement of visibility within it: overseeding. High values of v (> 106) would lead to the formation of big, though very sparse precipitation elements, but not noticeably improve visibility within the cloud: underseeding. Favourable values of v seem to lie around 10.3 — Cases of successful artificial seeding may be explained by natural seeding indirectly caused by the artificial one: double release. — Lastly, an inventory of the actual tropospherical clouds and cloud systems indicates that the main possibility for causing considerable artificial rainfall might be found within certain kinds of orographic cloud systems, to be treated in a following article.