WMOD00297

• Title: Hygroscopic Seeding in Oklahoma
• Date: 10/31/1971
• State: OK
• Weather Modification - Doc Type: Report

Introduction

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In July 1971, it was apparent that parts of southwest Oklahoma were
undergoing the second consecutive year of severe drouth, a nd in fact
many portions of the state were sufficiently low in precipitation to cause
great economic loss. Through the efforts of a concerned group of citizens
at ~1tus, Oklahoma, and the help of Senator Bellmon, Governor Hall, and
many other concerned state officials, a rainfall augmentation program was
organized under the direction of the Division of Atmospheric Water Resources
Management (DA WRM) of the Bureau of Reclamation, with funds provided
by the Federal Office of Emergency Preparedness (OEP).

The Oklahoma Drouth Relief Operational Project (ODROP) consisted of
two distinct projects: the seeding with hygroscopic material performed
by Flight Test Research, Inc. (FTR) and the silver iodide seeding performed
by Weather Sciences Inc. (WSI). In addition to doing seeding, a WSI
aircraft collected evaluation data. Overall control was centered at Norman,
Oklahoma, at the facilities of NOAA's National Severe Storms Laboratory
(NSSL). DAWRM personnel were located at NSSL, and used the excellent
NSSL radar as a vital tool for the program.

FTR operated from Altus Air Force Base at Altus, in the critical dry
southwest corner of Oklahoma.

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The FTR hygroscopic material airborne seeding represented the first
time this method has been utilized on an operational, as opposed to a
research, basis. FTR provided a large C-97 aircraft with a 40,000
pound payload capacity, and a dispenser system capable of putting out
as much as 15 tons of particles per flight. The basic dispenser system
was made available by Edwards Air Force Base. The Air Force uses it
to dispense water droplets for deicing tests, and the droplet sizes
required for the AF turn out to be just about what are required
for this hygroscopic material seeding. FTR loaded the system into the
aircraft at Edwards AFB, and flew to Altus AFB where the system was
adapted (with considerable modification) to the needs of this program.
The C- 97 aircraft was leased to FTR for this project by the Foundation
for Airborne Relief, a humanitarian foundation which shares the FTR
facilities at Long Beach and which is run by the former president of FTR,
. Mr. Russell o 'Quinn. The total flight crew used by FTR on this project
had been involved with FTR's operation of seven C-97's during the Biafra
food supply airlift in 1969. FTR's Vice-President and General Manager,
Mr. Earle T. Binckley, when with the Air Force at Wright Field, had

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