WMOD00377

• Contract/Permit #: 14-06-D-5640
• Project Name: Park Range Atmospheric Water Resources Program
• Title: Park Range Atmospheric Water Resources Program - Phase II - Part A
• Date: 11/15/1966
• Weather Modification - Doc Type: Report

practically all of the plume. The wind profile (where available), the mean
Emerald Mountain wind for the period of release and the parameter cr e U
estimated from the release-period winds at Emerald are also given. 0- e U
values were determined from:

range of e in radians
ere = 5
U = mean wind speed in m / sec
9 = lateral wind direction, radians

0' e U is a measure of the lateral dispe rsion of the wind from its speed and
azimuth angle fluctuations; hence, .it is a way of characterizing the expected
dispersion of tracers.

Figure 50 shows the correlation between the obtained Emerald Moun-
tain ere U value sand ZnS plume characteristic s; the correlation is not strong,
but is useful. Figure 51 shows that there is no correlation between Emerald
Mountain surface winds and the plume mean vector, while Figure 52 confirm s
the correlation between the plume mean vector and the 11,000 foot MSL wind

vector.

In the last two flights, a real-time freezing nuclei detector was flown
m conjunction with the ZnS detector. Figure 53 shows a portion of the re-
cord from the 11 May 1966 flight, Allowing for the 50 see time delay of the
freezing nuclei detector the coincidence is very good. On the flight of 14
May 1966 both trace rs were pul sed simultaneously at 1 cycle' per hour for
two cycle s to te st the ability to form a pulse of artificial freezing nuclei from
a square wave output of the generators. Tracks were flown continuously at
ten and eleven thousand feet at approximately a two nautical mile perpendicu-
lar distance f:rom the release site and just at the base of the foothills of the
ridge. The tracers were released from 1040 to 1110 and from 1140 to 1216
with the silver iodide generator operated until 1313. On these tracks the sig-
nal from the freezing nuclei counter started to decrease in amplitude at 1122
and was down to background by 1144. It remained at background level until

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