WMOD00576

• Title: Summary of Weather Modification Activities Reported in 1979
• Date: 7/1/1980
• Weather Modification - Doc Type: Report

Table 5.--Weather modification apparatus, seeding
agents and activities in CY 1979

Apparatus and Agent

Activities

Only ground-based AgI generators
(burners)

13

Ground-based AgI generators and
aircraft AgI pyrotechnics

7

Ground-based propane dispensers

2

AgI burners and pyrotechnics on
aircraft

9

AgI pyrotechnics only on aircraft

12

Aircraft with C02 dispensers

13,

Aircraft with pyrotechnics and
CO2 dispensers

4

Aircraft with AgI generators arid
C02 dispensers

3

Aircraft with polyelectrolyte
dispenser

I

Seeding Agents and Dispensing Rates

The active agents used for the reported weather modification activities
were silver iodide (AgI), crushed frozen carbon dioxide (dry ice (C02)),
propane, and polyelectrolyte (a polymeric material having electrical
charge). Table 5 shows AgI was used in most of the reported activities,
both air and ground-based. Dry ice was the second most used agent. In
many projects, two modification agents were used. One project used
polyelectrolyte.

..

J

Dispensing rates for the seeding materials varied with the location of
the apparatus, the type of equipment, and the purpose of the activity.
For example, the dispensing rate for AgI from one ground-based, arc~type
generator used for increasing precipitation can be set at 0.5 or 2.0 grams
per hour. A single, ground-based, propane fired liquid-fueled generator
can dispense up to 22 grams of AgI per hour. One liquid-fueled generator
on an airplane can dispense 240 grams of AgI per hour. A single

v

8