WMOD00558

• Project Name: Project Skywater, Sierra Cooperative Pilot Project
• Title: Project Skywater, Sierra Cooperative Pilot Project - Fall 1984 Status Report
• Date: 12/1/1984
• Weather Modification - Doc Type: Report

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increases or decreases in the Sierra Nevada and estimate the magnitude

of these changes. To achieve' their objective they utilized existing

observation systems and put into the field a wide range of other

sophisticated measuring equipI~ent, including weather radar sets and

aircraft. Table 2 gives a complete list of equipment used in SCPP

at one time or another since 1976 and its application. Because cloud

seeding studies deal in space and time scales varying from millimeters

and seconds (sampling changes in snow crystals) to thousands of

kilometers and days (monitoring storm systems over the Pacific Ocean),

a widely varied mix of equipment has been required.

Most measurement systems util:ized have been concentrated in or near

the ARB as shown in Figure 3a" which locates the major equipment sites

currently being utilized in SCPP. Site elevations can be found by

reference to Figure 3b, which is drawn to the same scale. Most data

collection on SCPP occurs during the intensive field season, which

runs from early January through March of each year.

The project aircraft have been hangared at McClellan AFB during each

of the intensive field seasons: conducted since 1976. On most winters

two aircraft have been used, a seeder aircraft and a cloud physics

aircraft. Both are high performance twin engine planes capable of

extended flight in the most severe wind and icing conditions. The

seeder aircraft is capable of seeding clouds by dispensing dry ice

pellets from a hopper or by dropping burning pyrotechnic flares

containing silver iodide. It carries a limited set of meteorological

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