SURVEY OF WEATHER MODIFICATION

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78-03425A002100020023-2
• Release Decision: RIFPUB
• Original Classification: S
• Document Page Count: 5
• Document Creation Date: December 23, 2016
• Document Release Date: August 6, 2013
• Sequence Number: 23
• Publication Date: March 1, 1968
• Content Type: REPORT

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SURVEY OF WEATBER MODIFICATION
Sources of Information:
This brief survey of the status of weather modification is based
on information from the following sources: (a) Dr. Earl G. Droessler
of the Office of Secretary of Defense (hest. Secretary, R&D). Dr.
Droessler is responsible for the coordination of Department of Defense
R and D in Meteorology and is the author of a portion of the final
report of the Advisory Committee on Weather Control. (b) Mr. Malcom
Ross, ONR. (c) Final Report of the Advisory Committee on Weather
Control, Dec. 31, 1957.
Present Capabilities for Weather Control:
Up Until about ten years ago our accomplishments in the field of
weather control or modification were very small, being limited to
examples such as the heating of citrus orchards to control frost and
the small scale dissipation of fog over airports by heating. During
the past ten years interest has expanded to cloud nucleation studies
(cloud seeding)-. It has been quite well demonstrated that the seeding
of suitable cloud formations in suitable geographical areas will usually
induce variable amounts of precipitation. At present, this is best
demonstrated in mountainous regions. The suitable clouds and topography
usually constitute conditions which would ordinarily be expected to
produce precipitation. What is usually induced by seeding is a small
increase in local precipitation over that which would be expected if
the same cloud formation were not seeded.
Some interesting results have been obtained in the dissipation of
cloud formations. In some cases fog, stratus, and small inactive cumulus
clouds can be dissipated by seeding from above. In field tests it has
sometimes been possible to clear "holes" in an otherwise Solid deck of
stratus, thereby makingit possible for .the ground to be seen from an
aircraft. (Such applications may be of interest to WAD.)
Equivocal results have been obtained from attempts to suppress
the formation of hail by seeding.
In general, the present known capabilities for controlling the
weather are quite modest.
Present Government Sponsorship Of R&D:
A number of Federal Government organizations have been andpresently
are engaged in activities in the field of weather modifications and cloud
physics. The most active groups are the Army, the Navy, the Air Force,
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the U. S. Weather Bureau, and the National Science Foundation.
The Army work on cloud physics and weather modification is centered
at the Signal Corps Engineering Laboratories, Fort Monmouth, New Jersey.
They have studied the effectiveness of various seeding materials and the
dissipation of supercooled stratus by seeding. In addition, laboratory
work at Fort Monmouth covers a range of basic experimentation on cloud
particles and environmental effects. Large cold chambers are utilized in
this work. In Volume 5 (Geophysical Sciences and Engineering) of the
1958 Annual Research Task Summary (U. S. Army), the Army projects are
listed as being under the direction of D. Deisinger, Chief, Physical
Sciences Division, ESL, with the principal internal investigator being
Dr. H. K. Weickmann of Fort Monmouth. A notation on the description of
a project on cloud modification (purpose: research into physics of cloud
dissipation and potentialities in tactical operations) indicated progress
was reduced by the unavailability of a research aircraft.
The Navy has devoted most of its attention to basic problems in
cloud physics. The Cornell Aeronautical Laboratory, under Navy contract,
is interested in the conversion of freezing rain to a less hazardous form
of precipitation and the suppression of aircraft contrails. The Institute
of Atmospheric Physics at the University of Arizona is accumulating data
which it is hoped will give an idea on the movement and variations of
flux of water available for precipitation. Various other contracts deal
with various problems in cloud physics.
The Air Force activity is centered at the U. S. Air Force Geophysics
Directorate, Cambridge, Mass. Laboratory work is in progress on a group
of investigations related to artificial nucleating materials: natural
nuclei, cloud droplets, ice crystals, etc. They are interested in the
inhibition of ice crystal formation in supercooled clouds, the modification
of aircraft contrails, factors related to visibility, etc. They have
measured and studied various detailed conditions in and around cumulus
clouds, and have done some interesting experiments on the dissipation
of stratus and fog by seeding from above. In one such field test conducted
in 1957 a clearing about 70 miles in length was made in a cloud deck (super-
cooled stratus) more than 3000 feet thick, making it possible for aircraft to make
VFR landing approaches in an otherwise solid overcast.condition. Contracts
with the University of Chicago and the University of Arizona cover investi-
gations on large scale factors which affect cloud growth, precipitation,
and weather modification. This includes experimental seeding of clouds.
The U. S. Weather Bureau activities include collaboration with other
agencies and some fundamental laboratory studies by the Physical Research
Division.
The U. S. Forest Service has sponsored or cooperated in several
weather modification projects.
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The National Science Foundation has made a number of grants for
the support of basic research in cloud physics and related subjects.
There are some eight such projects at five universities and one com-
mercial laboratory.
Magnitude of Federal Government Efforts:
It is difficult to place a dollar value on the Federal Government
expenditures in the field of weather control because it is difficult to
determine where among the various projects in cloud physics the line
should be drawn. However, Dr. Earl Droessler of the Office of the Secretary
of Defense indicated the total Federal Government expenditures in the field
of weather control and reasonably related areas in cloud physics is approxi-
mately $500,000-per year. The Navy devotes about half of the budget of
the Geophysics Branch, ONR, to cloud pl4sies projects. This would be
about $170,000 per year. According to the Final Report of the Advisory,
Committee on Weather Control, the National Science Foundation support
amounts to around $75,000 per year. These figures would indicate the
combined ArmY, Air. Force, and WeatherBureau contribution is a little
over $250,000 per year.
According to Dr. Droessler it is quite possible the Defense Depart-
ment agencies will have somewhat more money available for this type of
work in the future.
There are no apparent places where money is available for expenditure
on weather control but is not being used for one reason or another.
*There appears to be no concensus of opinion as to whether further
funds could profitably be used in this area. Dr. Droessler indicated in
effect that he felt the current level of effort is quite adequate to
support the work that can presently be done profitably and in a competent
manner. However a more realistic appraisal would probably be that increased
efforts directed toward increasing our basic knowledge of the mechanisms
involved in various weather phenomena would be quite desirable. Such a
conclusion would be in agreement with the Advisory Committee on Weather
Control. One difficulty is that there is probably quite a limited number
of competent investigators available in this area.
Future Possibilities:
It is of interest to consider where present and possible future efforts
may reasonably lead. Apparently the major interest so far (from an applied
standpoint) has been directed toward the modification of clouds by seeding.
It is becoming increasinly well established that this can be done under
suitable conditions on a local scale, and it may be possible that in the
future this can be extended to larger areas. However, it should be pointed
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outout that large scale cloud modification-would seem to imply equally
large scale alterations in atmospheric circulation patterns by some
means. Present knowledge appears to offer no really sound basis for
the belief that weather, on a large scale, can be altered by seeding.
Various possible routes toward large scale weather modification
have been proposed by various people. For instance, it appears obvious
that a factor in major air circulation patterns is the balance between
heat input into the atmosphere and heat output. One factor in this
process is the nature -of the surface Of the earth. Thus it is postu-
lated that weather patterns could be altered by large scale alterations
in patterns of vegetation, or by reducing the reflectivity of the
surface in polar regions (for instance by spreading carbon black), by
changing .ocean currents, etc. Also, it appears obvious that the evap-
oration of water from oceans and other large bodies of water is a
factor in observed weather and climate. It has thus been postulated
that the production of a large scale alteration in availability of
water vapor (for instance by decreasing evaporation by spreading cetyl
alcohol on the surface of a body of water, or by flooding of large
areas) should alter weather patterns. However such proposals are
generally based on assumptions (rather than knowledge) of the dynamics
involved in major weather systems and even if they would work, logistically
such plans would require a major national effort to carry out.
Although the above and other possible applications of weather control
have been proposed, the true need in this field is a great deal of rather
basic research directed toward establishing a foundation of-fundamental
knowledge to provide a more adequate basis for further applied efforts.
The areas in which fundamental knowledge is seriously lacking cover
almost all areas of cloud physics and meteorology related to weather
control. A few examples can be cited.
Although nearly all commercial cloud seeding involves introducing
freezing nuclei into supercooled clouds, very little is known about this
nucleation or freezing process. For instance, regarding the nuclei,
what is the relationship of such factors as chemical structure, size,
impurities, temperature, moisture? Very little is known about natural
nuclei. Can nucleation be prevented (the nuclei "poisoned")?
In many areas natural rain results not from freezing and sublimation
of water on nuclei but rather on condensation on nuclei. Theoretical,
laboratory, and field studies would be required to adequately understand
this process.
The mechanisms related to the normal inception, growth, trajectory,
and decay of clouds is very inadequately understood.
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(3 UM I
. It is known that electrical phenomena are associated with weather,
but it is not known how they are related. Are the electricaleffects
primarily by-products of other meteorological effects or are they major
factors in weather production?
Attempts are being made to construct increasingly more realistic
mathematical models of the-atmosphere. When such a model incorporates
the important features of the real atmosphere we will havean excellent
tool for exploring the effects of artificial modifications and a basis
for the intelligent planning of further physical experiments.
Conclusions:
The present status of weather control is such that limited local.
modifications are possible under proper cloud and geographical conditions.
Certain areas, such as Stratus dissipation and the modification of
contrails, would probebIy be of interest to WAD.- Beyond this, it is
difficult to see obvious applications of capabilities available at present
or in the immediate future. For example, the production of precipitation
by seeding requires specific conditions, and even then a statistical
increase in precipitation is all that has been demonstrated.
Potential capabilities, however, would certainly, make it of interest
to the Agency (and probably TSS) to follow the current activities of others
in this field and to evaluate ideas postulated from time to time.
The most obvious area in which further research is needed is in
various rather basic facets of cloud physics and meteorology. Govern-
ment financial assistance in this field is undoubtedly justified, from
economic, military, and defense standpoints. However, whether or not
active participation in the area of weather control is within the responsi-
bilities of TSS is a question which the writer feels is beyond the scope of
this survey.
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