WMOD00306

• Project Name: Sierra Cooperative Pilot Project
• Title: Sierra Cooperative Pilot Project - Operations Plan - 1986-1987
• Date: 10/1/1986
• Weather Modification - Doc Type: Report

required between generator on times. Three hours (2 hours before nucleation
occurs and 1 hour for fallout) will be required for the last of the seeding
material to reach activation and fallout. If the generators are off for 3
hours and it takes another 3 hours for the next release of seeding material to
reach nucleation levels and fallout, there will be a minimum of 3 hours

between seedi ng effects measured at the ground. Thi s shoul d be adequate
separation for evaluation purposes.

Once a generator is turned on it shou 1 d be 1 eft on for the durat i on of the

experiment. However, based on updates from GUIDE, additional generators can
be activated if wind conditions provide directional targeting.

Seedi ng rates and formul as wi 11 be standardi zed am()ng~L~h~_different coopera-
L 'dte.{I'~o ( tors I generators. Rates wi 11 be between/20 to 30 gm/hr of Aglkith the AgI-

jJ r) I \"",,-, -----.------------ ______._____.____

,{I}-I acetone mixture having the additive NH4CL04 at a 30 mole ratio. This same
formulation will be used on the seeder/tracer aircraft. PGE will not have the

NH4CL04 additive.

G\Al0 6

1. GUIDE Model Criteria for Ground Seeding
In running the ground based delivery version of the GUIDE the following
assumptions will be made for targeting:
a. The 2 cr concentration above the center line of the plume will be used.
The Pasquill-Gifford neutral stability curve will be used to calculate this

1 eve 1.

b. When the 2cr concentration level reaches the -6 oC level nucleation will

be assumed to take place at a rate comparable to that shown in DeMott et
al. (1983) for the AgI NH4I NH4CL04 20 mole formulation (30 mole not shown
in paper). The location of the intersection of the 2 plume with the -6 oC
level will be specified.

II I-4

I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I