WMOD00286 ‎(2)‎

• Title: Final Report for the Utah/NOAA Snowpack Chemistry Program
• Date: 9/1/1983
• State: UT
• Weather Modification - Doc Type: Report

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2

Along these lines a preliminary study that had been
conducted in April, 1982 found only 12% of the snowpack
sampled contained silver concentrations significantly above
the natural background level. This number of significant
samples was on the low side of results found in a similar
investigation conducted in the Truckee-Tahoe Project in the
Central Sierra Nevada (~). The project using similar seed-
ing technology found that up to 30% of the samples collected
during seeded storms contained significant silver.

Two problems were noted in the April, 1982 Utah study.
They were: (1) times of sampling; and (2) locations of
sampling. In regard to (1) it was noted that the snow pro-
files were collected late in the 1981-82 season. It is
possible that this late in the season, some snowmelt had
already occurred. The densities of these samples were rela-
tively high, indicative of an aging snowpack and problems
with recrystallization and dry deposition were considered of
possible importance.

With regard to (2), trajectory modeling work of Elliot:
and others for this area suggests that the seeding aerosols
may 'we11 have their greatest effect on the next plateau to
the east. This plateau is approximately 20-30 miles down-
wind of where the 1982 samples had been collected. There-
fore, it was recommended that future programs should involve
collection times closer to actual dates of snowfall and
include collections from more easterly sites.