A new method of stimulating convective clouds to produce rain and hail

✍ Scribed by E. G. Bowen

• Book ID: 104571273
• Publisher: John Wiley and Sons
• Year: 1952
• Tongue: English
• Weight: 558 KB
• Volume: 78
• Category: Article
• ISSN: 0035-9009
• DOI: 10.1002/qj.49707833505

✦ Synopsis

Abstract

The theory of the formation of rain by coalescence leads logically to the suggestion that, if water drops of suitable size are sprayed into the base of a convective cloud, the drops will ascend in the upward air current, will grow by coalescence with the cloud droplets and may ultimately fall out as rain. Calculations show that under appropriate conditions the drops could attain a diameter greater than 1 mm and emerge from the base of the cloud from 20 to 60 min after water had been sprayed into it.

Eleven experiments have been carried out to test the possibility of the method. In 10 cases, distinct changes occurred following the introduction of a water spray into the selected cloud. In 4 of these, virga fell from the cloud and it dissipated soon afterward. In 4 cases, rain or hail appeared shortly after spraying. On only one occasion were no results observed.

The results suggest that the method might be useful for the artificial stimulation of rainfall, but further experiments are required to fully establish the mechanism.