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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pure SF6. The release rate will depend on atmospheric conditions but

may range from 0.63 to 2.52 g s-l. Consistent flow rates from each

bottle will be maintained through use of a flow regulator and flow

meter. The bottles will bE! weighed before and after each release epi-

sode in order to measure the total mass released. The SF6 will be

sampled with automatic sequential bag samplers. Each sampler consists

of eight separate pulse p\Jmps that fill individual one or two liter

Tedlar bags over a selectable time interval of 5 min to one hour. An

interval of one hour will be' employed in the present work. Activation

of the samplers can be delayed in time from 1 to 54 hr. This delay

allows some match of the data collection time period with periods of

anticipated weather. All samplers will be set to begin operation at

the same time.

Release of the SF 6 wi:ll be from either of two sites. (Only one

site will be used in any onl~ experiment.) One site will be Adamsville

where rawinsondes are launc:hed (see Fig. 1). This site is at an eleva-

tion of 1,711 m and is appr'oximately 20 km upwind of the base of the

Tushar Mtns. It will be used in order to simulate the valley locations

at which most ground genE!rators are placed in the Utah operational

seeding project. A concern is that valley locations may be unfavorable

for effective seeding because of trapping of seeding material in dead

air beneath inversions or because of airflow parallel to or away from

rather than toward the mountains. The experiments should shed light on

these concerns.

A second SF6 release site will be atop Jack Henry Knoll (see Figure

1). This site is about 30 km southwest of the base of the Tushar Mtns

but at an elevation of about 2440 m MSL. A remotely operated generator

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