Accession Number : AD0781837

Title :   A History of Air Weather Service. Weather Modification 1965-1973,

Corporate Author : AIR WEATHER SERVICE SCOTT AFB ILL

Personal Author(s) : Chary,Henry A.

Report Date : JUN 1974

Pagination or Media Count : 31

Abstract : Starting in 1965 with cakes of dry ice suspended from balloons, then testing vented liquid carbon dioxide, vented liquid propane, and silver iodide AWS gradually developed a ground based cold fog dissipation system. Three such systems, all using vented propane, are now operational. In 1967 AWS undertook airborne dissipation of cold fog by seeding with crusted dry ice. AWS investigations into warm fog dissipation started in 1968 when jet engines were used to clear warm fog temporarily from the Travis AFB runway. Subsequently several tests were sun using hygroscopics and helicopter downwash. No operational warm fog dissipation system has yet evolved from these early works. Twice AWS has tried to alleviate the ice fog problem, but both endeavors failed to generate the desired clearings. Precipitation augmentation for drought relief is a twice used AWS capability. AWS has participated in such programs in the Philippines and in Texas. AWS's current operational weather modification capabilities include airborne and ground based cold fog dissipation and precipitation augmentation. (Author)

Descriptors :   *Weather modification, History, Air force operations, Fog, Ice fog, Rainfall, Atmospheric precipitation, Artificial precipitation, Cold regions

Subject Categories : Meteorology

Distribution Statement : APPROVED FOR PUBLIC RELEASE