Evening star., 1953-01-05
Scientists Foresee !;
Roin Storage in Sky
Soy Ice Crystal Reservoir
In Clouds Is Possibility
By Thomos R. Henry

III \iOuuS - IOSSlDllity
By Thomos R. Henry
There is possibility Of making rain
reservoirs in the sky.
This is stressed in General Electric
Co.'s final report on Project Cirrus
the f1ve-year investigation by its scien-
lists on the possibility Of producing rain
by seeding" clouds with particles of
dry ice or silver iodide.
The corporations association with
this still highly controversial project Is
over now. but, according to the report,
enough interest has been aroused SO
that it is bound to be continued by
others with investigations along many
lines.
From the start. it was quite outside
the company's business interests. Its
scientists, DR.. Irving Langmuir and DIR.
Vincent j. Schaefer, happened to en-
counter certain phenomena in cutie
unrelated Investigations, and the i'm
plications for general welfare seemed
so great that the lines were followed.
Much Of the work has been carried on
under auspices Of the ONCE Of Naval
<YSOO0A&AA AAV4Ns
Started With Gas Masks.
It all started just before the war, ac-
cprding to the report. with investiga-
tionS OF gas masks. The Army feared
the Germans might have I'D their
sleeves some deadly gas with such fine
particles that it would pass easily
through existing gas mask filters. The
problem was assigned to General Elec.
trio Co.
The investigation involved making
smokes" Of various particle sizes to
test filters. This, in turn. led to an
investigation Of producing smoke
screens for shielding military opera
tions, and developments in this line led
to the quite unexpected rainmaling
possibilities.
The possibilities have neither been
accepted nor rejected by the Weather
Bureau and other Government agencies.
and much further research is planned.
In bidding goodby to the project, how
ever. General Electric Co. feels some
success In rainmaking has been unuues-
tionable. that there are obvious diff
ncultieS in the way Of complete success.
and that hitherto unexplored possibili-
ties have arisen.
"The results" says the final report.
point to significant possibilities in
the widespread modifying of weather
conditions. Such work could easily have
profound economic political and mill
tary effects"
Ice Crystals May Be Stored
AS for the rain reservoirs, says the
report:
"The production Of specific regions
in the free atmosphere containing
high concentrations Of ice nuclei or
potential ice nuclei is an interesting
possibility. Cold middle clouds, even
though having no appreciable moisture.
may be used as holding reservoirs to
store ice crystals until they come in
contact with lower clouds of greater
thickness or are entrained into cool or
cold cumulus clouds.
Similarly, the ice crystal residue
from seeded but small cumulus clouds
may be entrained at low level into much
larger cumuluS clouds forming in their
vicinity. In this way an effect Of con-
siderable magnitude is produced as the
super-cooled regions are infected at a
lower level than would otherwise be
possible.
Clouds which form as moist air is
forced to rise when it encounters a
barrier. such as mountain range, are
very common in mountainous regions.
and they often form continuously for
many days. Relatively little precipita-
ton from them reaches the earth, ex-
rim a.
rocks, or as scattered snow crystals.
II techniques could be devised to
cause q widespread and effective pre-
cipltation OF such clouds, the depth of
snow pack in the vicinity of mountains
might be markedly increased. Such a
result would be Of great Importance,
since the snow pack on mountain slopes
is very valuable in stabilizing the
streams which flow from such regions.
These streams, in turn, have great sig
ntficance from standpoint of electric
power and water supply"
Clouds Might be Dispersed, Also.
other still improved possibilities cited
are the dispersal of clouds along heavily
travelled airways and over airports,
modification Of thunderstorms, and
prevention Of hail which sometimes
ruins crops over large areas.
But the General Electric Co. remains
highly cautious and conservative in
it's claims.
Man is just beginning to UNDER
stand the first principles of weather
modification" says the report. 1T ap-
pears he can cause long range effects
on the weather in about the same way
a small boy might affect traffic over
a relatively large area near New York
city by dropping a handful Of tacks
at strategic highway intersection"
AS yet, says the report, there is
little prospect Of affecting drought
areas. There must be water In the sky
to begin with. Usually the skies over
q drought region are cloudless. The
only possibility is by creating rain
clouds a long distance away where con-
ditions are favorable, and hoping that
the general circulation will carry them
where they may do some good.
n.>e&:@ne -~l An~>..