WMOD00376

• Contract/Permit #: 14-06-D-5640
• Project Name: Park Range Atmospheric Water Resources Program
• Title: Park Range Atmospheric Water Resources Program - Phase II - Parts A and B
• Date: 10/6/1967
• Weather Modification - Doc Type: Report

to what extent do artificial nuclei participate in ice crystal

formation, and how is this participation reflected in precipita-

tion on, and subsequent run-off from, the target area?

what combination of operating criteria, technique s and equip-

ment will produce the greatest desired effect on precipitation

with the least cost and operational complexity?

To answer these questions, research and development work has been aimed
at the general areas of:

o diffusion analysis

o

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ice nuclei generation

ice nuclei detection

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precipitation meteorology, and

evaluation

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and support work has led to instrumentation and data proce ssing develop-
menL Experimental operations have produced the data needed by R & D
efforts as well as contributing to the development of efficient operational
procedures and techniques for future, large-scale field programs,

The program has made substantial progress toward answering
major technical questions as they apply to the Park Range,. The operating
criteria for nucleation have been identified, the meteorological conditions
favoring major precipitation periods isolated, a scheme for self-activation
of nuclei gene rators developed, a procedure for evaluation of effects on
precipitation in a single storm period tested, and promising techniques
for nuclei detection in snow samples explored, It has not yet been' possi-
ble to develop a satisfactory method for detecting silver iodide nuclei in
individual snow crystals, but there is some hope that it may be practical
to infer their presence from crystal structure.

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