Large Scale Effects of Cloud Seeding. 1970-71 Season and Four Year Summary

The report is based on four years of data on the large scale effects of cloud seeding. The study was conducted in the area surrounding a randomized seeding project in Santa Barbara County, California sponsored by the Naval Weapons Center, China Lake, California. Seeding was accomplished from a point source using pyrotechnic seeding devices. The seeding and observation unit was a convective band. Substantial statistical evidence is presented showing that precipitation has been significantly increased over a large area 70 to 125 miles from the seeding source. Evidence is also provided showing that the seeding effect is highly temperature dependent and that the time duration of bands is significantly increased as a result of seeding. Also shown is the interaction between convective bands, the possible effects of seeding on surface pressure and the diurnal effect of seeding. See also report dated Oct 1970, AD718814.