WMOD00303 ‎(2)‎

• Title: CRADP Operations Plan - 1985-86 Winter
• Date: 11/1/1985
• Weather Modification - Doc Type: Report

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complex mountainous terrain is a major area of
uncertainty for winter orographic weather modifica-
tion. The ~asic approach will be to monitor AgI
plumes from ground generators, or AgI lines
released from aircraft, with an airborne ice
nucl eus counter simi 1 ar to the work reported by
Super (1974). Ground generators will be manually
operated at one or more of the sites shown on
Figure 1. Generators will be transported to the
sites by helicopter or snowmobile depending upon
location.

Ground-released AgI plumes will be sampled by
aircraft under VFR (visual flight rule) conditions
by making horizontal passes, generally from 100 to
1000 ft (30 to 300m) above the ground, approxima-
tely perpendicular to the wind at a given downwind
distance. Normally at least two passes will be
made at each altitude so that the lag time of the
counter can be used to estimate the plume edge on
each side. Pairs of passes will be made at alti-
tude increments from near the surface to above the
plume, providing a vertical and horizontal cross-
section through the plume. The fine structure of
the plume is not available with this approach due
to the slow counter response as ice crystals must

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