WMOD00173

• Applicant: Colorado State University
• Project Name: N. Central Mountains
• Date: 11/15/1984
• Weather Modification - Doc Type: Application

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The data available from the study area will include rawinsonde

observations, microwave radiometer observations, vertical pointing Ku-band

radar observations, surface weather measurements, visual observations, and

reports from observation aircraft.

Using data from the above sources, the CSU Research Coordinator, CSU

licensed operator and the airborne seeding crews will coordinate by telephone

each morning to prepare a schedule of seeding operations for the ensuing 24

hours.

4. Types of Aircraft

Two (2) aircraft will be utilized for the project. Their missions will

be as follows:

a. A specially instrumented King Air provided by the National Center

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for Atmospheric Research (NCAR) will be used to monitor seeding material

and to record microphysical data in and downwind of the target area.

It

will also make soundings and measurements of the environment in which

clouds are forming. It will not release any seeding materials.

b. A twin engine aircraft will be used to burn silver iodide on

selected days.
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5. Seeding Devices and Rates

Aircraft seeding will be accomplished with aerial acetone burners.burning

one of several sQl~tJ.Qns_at_~a~es vary~n&-from 30-l20 g/hr. The ice nuclei
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yield effective at _20oC is approximately 10 active nuclei per gram. Three

solutions will be tested during the course of the experiment. These are

silver iodide-silver chloride-ammonium chloride (AgI-AgCl- NH4Cl) , silver
iodide-silver chloride (AgI-AgCl) and silver iodide-sodium iodide (AgI-NaI).

The material will be dispersed in a tight circu~ pattern from the aircraft

so that a continuous narrow plume will move into the cloud. The research

aircraft will penetrate this plume.