Co-operation with -70- 



Other Projects 



So many and so active are the organizations for this purpose, that 

 there has been some concern over the effects of introducing such quantities 

 of silver iodide into the atomosphere. Studies by the Research Group of 

 the project indicated that silver iodide can continue in the atmosphere for 

 an almost indefinite period, and although its usefulness can be modified by 

 sunlight, the practical effects of such modification are not significant when 

 the silver iodide is within or below the clouds. Finally, the analyses and 

 calculations of Langmuir (page 55 et seq.), indicate that periodic silver- 

 iodide seeding in New Mexico produced a tendency toward periodic rainfall 

 and temperature fluctuations that extended significantly all over the United 

 States. 



Currently, some members of the Research Group feel that there is a 

 definite possibility that some abnormal flood conditions of recent years have 

 been caused, at least to a contributing degree, by commercial seeding oper- 

 ations in the West. 



In addition to the commercial operators, who seed for the benefit of 

 others, at least one electric power company has done extensive work in this 

 field. This is the California Electric Power Company of Riverside, Cali- 

 fornia. This company's use of seeding stems from its concern over an 

 adequate supply of water to operate its hydroelectric generating stations. 

 Not only does it credit the seeding with increasing its hydroelectric out- 

 put by many millions of kilowatt -hours, but it also declares it has produced 

 thousands of extra acre -feet of water for the city of Los Angeles. 



Interesting cloud-seeding experiments were also conducted by John 

 A. Eattle, consulting meteorologist of Eeaumont, California, in California, 

 for the San Diego County Weather Corporation and the Santa Ana River 

 Weather Corporation. The experiments were conducted over the entire 

 area of San Diego County plus the Santa Ana River drainage area in Orange, 

 Riverside and San Bernardino Counties. The two corporations responsible 

 represented various water agencies in those regions, where the relative 

 scarcity of water makes any possibility of increasing the annual rainfall 

 attractive. 



Silver iodide was used in the seeding. Unseeded areas were used for 

 control zones, in comparison with seeded areas. About 20 per cent more 

 rain fell in the target area than in the control area; in other words, 1,400,000 

 acre-feet of additional water. Statistical analyses indicated that the chances 

 that the cloud seeding did not have a positive effect on the precipitation meas- 

 ured varied anywhere from 12-to-l to 10,000-to-l, depending on the area 

 involved. '^2) 



