WMOD00276

• Contract/Permit #: 85-5071
• Title: Cooperative Weather Modification Research Program - 1985 Field Operations Plan
• Date: 1/1/1985
• State: UT
• Weather Modification - Doc Type: Report

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mountains to 5-10 km east of the base by a factor varying from 1.3 to

2.0 depending on the depth elnd convective nature of the clouds. During

a cloudy period the liquid welter appears to develop first over the moun-

tains, and it remains there toward the end of the period after it has

disappeared from other direlctions. These effects on the liquid water

are clearly orographic. The evidence suggests the liquid water is

located at temperatures colder than -5 C or at altitudes greater than

about 3.3 km MSL. Research on delivery of seeding materials to clouds

over the Tushar Mtns from the ground generators used in the operational

project suggests delivery is frequently limited by adverse meteorologi-
cal conditions.
The 1985 field research effort and subsequent data interpretation
and analysis will again be conducted by the Utah Division of Water
Resources and associated groups. The field studies will again be in
the Tushar Mtns area durin~J the period 15 January to 15 March. The
major objectives of the rese~arch remain essentially the same and are
concerned with:
1) assessing the transport and delivery of seeding material from
ground-based generators to the clouds over the Tushar Mtns, and
2) describing the spatial and temporal distribution of super-
cooled liquid water in the clouds, the physical processes
responsible for prec:ipitation development, and the trajectories
of cloud and precipi1tation particles.
In 1983 the research toward these objectives was largely statistical in
nature with less emphasis on case-studies of the data. In 1985, on the
other hand, the reverse emphasis will prevail because the available

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