Science, and transportation united states senate

1o' mailer of this Treat}', have jeopardized the supreme interests

17 of its country. It shall give notice of such withdrawal to all

18 olher Parties to the Treaty three months in advance.

V.) Article VI

20 "1. This Treaty shall be open to all States for signature.

21 Any State which docs not sign this Treaty before its entry

22 into force in accordance with paragraph 3 of this Article

23 may accede to it at any time.

24 "2. This Treaty shall be subject to ratification by sig-

25 natory States. Instruments of ratification and instruments of

740

6

1 accession shall be deposited with the Governments of the

3 which are hereby designated the Depositary Governments.

4 "3. This Treaty shall enter into force after its ratifica-

5 tion by the States, the Governments of which are designated

6 Depositaries of the Treaty.

7 "4. For States whose instruments of ratification or ac-

8 cession are deposited subsequent to the entry into force of

9 this Treaty, it shall enter into force on the date of the de-

10 posit of their instruments of ratification or accession.

11 "5. The Depositary Governments shall promptly inform

12 all signatory and acceding States of the date of each signa-

13 ture, the date of deposit of each instrument of ratification of

14 and accession to this Treaty, the date of its entry into force,

15 and the date of receipt of any requests for conferences or

16 other notices.

17 "6. This Treaty shall be registered by the Depositary

18 Governments pursuant to Article 102 of the Charter of the

19 United Nations."

Appendix S

Reported Cases on Weather Modification

Slutsky v. City of Neiv York, 197 Misc. 730, 97 N.Y.S. 2d 238 (Sup. Ct, 1950).

Southwest Weather Research, Inc. v. Rounsaville, 320 S.W. 2d 211 (Tex. Civ.

App., 1958), and Southicest Weather Research, Inc. v. Duncan, 319 S.W. 2d

940 (Tex. Civ. App. 1958), both affd. sub nom. Southwest Weather Research, Inc.

v. Jones, 160 Tex. 104, 327 S.W. 2d 417 (1959) .

Summerville v. North Platte Valley Weather Control DIM., 170 Neb. 46, 101

X.W. 2d 748 (1960).

Pennsylvania Natural Weather Assn. v. Blue Ridge Weather Modification

Assn., 44 Pa. D. & C. 2d 749 (1968) .

(741)

Glossary of Selected Terms in Weather Modification 1

GLOSSARY _!/

ACRE- FOOT— The volume of water required to cover

one acre to a depth of one foot: 43,560 cubic feet,

325,852 gallons

AEROSOL— A colloidal system in which the dispersed

phase Is composed of either solid or liquid particles,

and in which the dispersion medium is some gas.

usually air.

There is no clear-cut upper limit to the size of

particles comprising the dispersed phase in an aerosol,

but as in ail other colloidal systems, it is rather com-

monly set at 1 micron. Haze, most smokes, and some

fogs and clouds may thus be regarded as aerosols.

AIRCRAFT SEEDING— The use of aircraft to dispense

cloud seeding agent*.

ALTOCUMULUS— A principal type of cloud, 8,000 to

20,000 feet, consisting of a layer where the denser

parts have modified cumuliform characteristics of

roundness and sharpness of outline.

ALT08TRATU8 — A principal type of "middle" cloud

(altitude approx. 8,000 to 20,000 feet), appearing

as a fairly uniform grey layer that often covers the

entire sky.

ANVIL CLOUD— Popular name given to a cumulonim

bus cloud whose upper, ice-crystal portion is spread

out horizontally to give the appearance of an anvil.

In the International Cloud Classification, this is a

"cumulonimbus caplllatus" cloud with the supplemen

tary feature "incus."

ARTIFICIAL NUCLEATION — Any process whereby

the nucleation of cloud particles .s Initiated or accel-

erated by human intervention.

CAP CLOUD -An approximately stationary cloud, on

or hovering above an Isolated mountain peak. It is

formed by the cooling and condensation of humid air

forced up over the peak.

CELLULAR CONVECTION — An organized, convecUve.

fluid motion characterized by the presence of distinct

convection cells or convectlve units, usually with up-

ward motion (away from the heat source) in the cen-

tral portions of the cell, and sinking or downward flow

in the cell's outer regions.

CHAFF— Metallic, electrical dipoles, several centime-

ters long, commonly made of fine wire.

The original use of chaff, dropping large quantities

of It from aircraft in WWII, was to jam enemy radars

It is now used experimentally to alter the electrical

properties of thunderstorms.

CHAFF SEEDING -The dispensing of chaff into a cu-

mulonimbus cloud for the experimental purpose of

altering the cloud's electrical structure and hence

affecting the occurrence and character of lightning.

It is hypothesized that the chaff is the medium for

leakage currents (through corona point discharges)

which forestall the development of the charge centers

necessary for lightning tormatioa

CIRRUS — A principal cirriform cloud type, composed of

ice crystals aggregated into delicate wisps or patches

at high altitudes.

The term "cirrus" is often used as a generic term

for ail cirriform clouds.

CLOUD — A visible aggregate of minute water and/or

ice particles in the atmosphere above the earth's

surface. Cloud differs from fog only In that the latter

is, by definition, in contact with the earth's surface.

Clouds form in the free atmosphere as a result

of condensation of water vapor In rising currents of

air, or by the evaporation of the lowest stratum of

fog. For condensation to occ\ir at the point of satura-

tion or a low degree of supersatu ration, there must

be an abundance of condensation nuclei for water

clouds, or ice nuclei for ice-crystal clouds. The size of

cloud drops varies from one cloud type to another,

and within any given cloud there always exists a fin-

ite range of sizes. Generally speaking, cloud drops

range between one and one hundred microns in di-

ameter, and hence are very much smaller than rain

drops.

cloud physics dealing with extremely small-scale phe-

nomena, particularly the molecular-scale processes of

evaporation, condensation, and freezing of cloud par-

ticles, and the complex Interactions, Including elec-

trical effects, among cloud particles.

CLOUD MODEL — In general, any idealized represents

tkon of a cloud or cloud processes. Increasingly, this

term is used for mathematical representations of cloud

processes, particularly those formulated for numerical

solution on electronic computers

CLOUD MODIFICATION -Any process by which the

natural course of development of a cloud is altered by

artificial means.

CLOUD PHYSICS -The body of knowledge concerned

with physical properties of clouds in the atmosphere

and the processes occurring therein

CLOUD SEEDING — Any process of injecting a sub-

stance into a cloud for the purpose of influencing the

1 From Project Skywater ; 1973-74 Biennial Report. U.S. Department of the Interior.

Hur»-nu of Reclamation. Division of Atmospheric Water Resources Management. REC-ERC-

70-21. Denver, December 1976. pp. A-21 to A-25.

(742)

743

fers to the injection of a nucleating agent, but some-

times alludes to substances which do not directly

affect nudeation (such as carbon black).

CLOUD SEEDING AGENT- Any variety of substances

dispensed for the purposes of cloud seeding. In addi-

tion to the commonly used silver Iodide and dry ice,

a number of other materials have been experimented

with for various purposes, for example: calcium chlor-

ide, urea, metaldehyde, chlorosulfonlc acid, carbon

black, common salt, and water spray.

COALESCENCE — In cloud physics, the merging of two

water drops into a single larger drop.

COALESCENCE EFFICIENCY -The fraction of all col

lis ions between water drops of a specified size which

result in actual merging of the two drops into a single

larger drop.

CONDENSATION — The physical process by which a

vapor becomes a liquid or solid; the opposite of evap-

oration. In meteorological usage, this term is applied

only to the transformation from vapor to liquid; any

process in which a solid forms directly from Its vapor

is termed sublimation, as is the reverse process.

CONDENSATION LEVEL -That level in the atmos-

phere at which saturation and hence condensation,

will occur in a column of rising air. This occurs by

virtue of the adlabatic cooling of the air as it rises.

CONDENSATION NUCLEUS — A particle, either liquid

or solid, upon which condensation of water vapor be-

gins in the atmosphere. See nudeation.

CONTROL CLOUD— In doud seeding experiments on

Individual douds, a. doud chosen to remain unseeded,

but is otherwise monitored as if it had been, in order

to provide data for comparison with seeded douds.

CONVECTION— 1. In general, mass motions within a

fluid resulting in transport and mixing of the proper-

ties of that fluid.

2. As specialized in meteorology, atmospheric motions

that are predominantly vertical, resulting in vertical

transport and mixing of atmospheric properties.

CONVECTION CURRENT — (or convective current)

Any current of air involved in convection. In meteor-

ology, this Is usually applied to the upward moving

portion of a convection circulation, such as a thermal

or the updraft In cumulus douds.

CUMULI FORM - Llxe cumulus; generally descriptive of

all douds, the principal characteristic of which Is ver-

tical development In the form of rising mounds, domes,

or towers.

CUMULONIMBUS— ( Commonly called thundercloud,

thunderhead, thunderstorm.) A principal doud type,

the ultimate stage of development of cumulus or con-

vective douds. They are very dense and very talL

commonly 5 to 10 miles In diameter and sometimes

reaching a height of 12 miles or more. The upper

portion Is at least partly composed of ice crystals,

and often takes the form of an anvil ("Incus") or

vast plume The base of the doud Is Invariably dark

and often accompanied by low, ragged douds.

CUMULUS — A principal doud type, actually a doud

"family" all of which are characterized by vertical

development; a convective doud.

DEFTV88ION — In meteorology, the exchange of fluid

parcels (and hence the transport of conservative prop

erties between regions In space. In the apparently

random motions of a scale too small to be treated by

the equations of motion.

In meteorology, the diffusion of momentum (vis-

cosity), vortlclty, water vapor, heat (conduction),

particulate matter, and gaseous components of the

atmospheric mixture, have been studied extensively.

The atmospheric motions diffusing these properties

may in many cases be of much larger scale than the

molecular, the exchanging parcels being called eddies,

and the diffusion equation extended by analogy to

turbulent diffusion

DOPPLER EFFECT— (Also called Doppler shift) The

change In frequency with which energy reaches a

receiver when the receiver and the energy source are

in motion relative to each other.

DOPPLER RADAR— A radar which detects and inter

pre is the Doppler effect in terms of the radial velocity

of a target The signal received by a radar from a

moving target differs slightly In frequency from the

transmitted wave.

Doppler radar la widely used In doud studies

because it enables the deduction of the motions of

doud and precipitation partides.

DRY-ICE- Solid carbon dioxide (CO 2 ). It evaporates

directly from solid to gas at a temperature of -78. 5* C

DRY-ICE SEEDING — The dispensing of dry-ice pellets

Into supercooled douds for the purpose of transform

Ing the supercooled droplets Into ice crystals, which

then grow and fall out Dry ice creates a sufficiently

cold environment around the droplet* for them to

undergo spontaneous nudeation

ECHO— In radar, a general term for the appearance,

on a radar Indicator, of the radio energy returned

from a target More explicitly, It refers to the energy

reflected or scattered back from a target

744

FREEZING NUCLEUS — Any particle which, when pre

growth of an Ice crystal about itself (see nudeatlon).

GLACIATION— In cloud physics, the transformation of

cloud particles from water drops to ice crystals

GROUND GENERATOR— In weather modification, al

most invanabh referring to silver iodide smoke gen

erat/>rs that are operated on the ground (as opposed

to airborne equipment).

HAIL SUPPRESSION — Any method of reducing the

damaging effects of hailstorms by operating on the

hail producing cloud.

The currently prevailing hypothesis is that silver

iodide seeding provides more hailstone nuclei (and, at

the same time, reduces the amount of supercooled

water available to build up large hailstones) with the

net effect that the hail that reaches the ground Is

smaller and less damaging, and also has a higher

probability of melting before reaching the ground

HYGROSCOPIC NUCLEI — Condensation nuclei com

posed of salts which yield aqueous solution., of a very

low equilibrium vapor pressure compared with that of

pure water at the same temperature. Condensation

of hygroscopic nuclei may begin at a relative humidity

much lower than 100 percent (about 75 percent for

sodium chloride), while on so-called non- hygroscopic

nuclei, which merely furnish sufficiently large (by

molecular standards ) wettable surfaces, relative hu-

midities of nearly 100 percent are required. "Damp

haze" is formed of hygroscopic particles In the process

of slow growth in relatively dry air

HYGROSCOPIC SEEDING -Cloud seeding with hygro

scopic material which encourages condensation and

collect* water vapor

ICE CRYSTAL— Any one of a number of macroscopic

crystalline forms In which ice appears, Including hex

agonal columns, hexagonal platelet*, dendritic cry

stals, ice needles, and combinations of these forms

I IE CRYSTAL CLOUD- A cloud consisting entirely of

ice crystals (such as cirrus); to be distinguished in

this sense from water clouds and mixed clouds

ICE NUCLEUS - Any particle which serve* as a nucleus

in the formation of ice crystals In the atmosphere,

used without regard to the particular physical process

involved in the nucleation.

Due to an apparent scarcity of natural ice nuclei

(or. at least, freezing nuclei) in the atmosphere, cloud

-eeding with ice- nucleating agents become* a practi

cal endeavor Both sliver iodide and dry ice perform

the function of nucleating ice in an aggregate of su

percooled water droplet*

ICE- PHASE SEEDING -Cloud seeding with an agent

which serves as an artificial ice nucleus.

ISOHYET — A line drawn on a map connecting geo

graphical points having equal amounts of precipitation

during a given time period, or for a particular storm

LIQUID WATER CONTENT — ( Abbreviated LWC. (The

amount of liquid water (that is, not counting water

vapor) in a cloud, usually expressed as grams of

water per cubic meter of cloud volume.

MESO-SCALE— In meteorology: having characteristic

spatial dimensions somewhere between 1 and 100

miles, usually implying between 5 and 50 miles.

NUCLEATING AGENT — (or nucleant) In cloud phy-

sics, any substance that serves to accelerate the nu

cleation of cloud particles Nucleating agents may

themselves be nuclei (silver iodide, salt, sulfur di

oxide, dust ) or they may enhance the nucleation en-

vironment (dry, ice, propane spray ).

NUCLEATION — Any process by which the phase

change of a substance to a more condensed state

(condensation, sublimation, freezing) is initiated at

certain loci (see nucleus i within the less condensed

state.

A number of types of nucleation are of interest

phase change from vapor to liquid is of decisive im-

portance in analyses of all cloud formation problems.

The physical nature of freezing nuclei which may be

responsible for the conversion of drops of supercooled

water into ice crystals is critically important in pre-

cipitation theory, us is also the clarification of the role

of spontaneous nucleation near -40*C The impor

tance of sublimation nuclei is promoting the growth of

ice crystals directly from the vapor phase is doubtful

NUCLEUS — In physical meteorology, u purticle of any

nature upon which, or the locus at which, molecules

of water or ice accumulate as a result of a phase

change to a more condensed state; an agent of nu

cleation.

NUCLEUS COUNTER -Any of severul devices for de

termining the number of condensation nuclei or ice

nuclei in a sample of air.

NUMERICAL MODEL— In meteorology, a mathemati

cal formulation of atmospheric processes constructed

so that the dynamical and thcrmodynamical equations

of atmospheric motion can be solved by numerical

methods on electronic computers

OROGRAPHIC CLOUD- A cloud whose lorrn and c\

tent is determined by the disturbing effects ■>( imi

graph>. mountains, upon the passing flow of ,ur Me

745

cause these clouds are linked with the form of the

at all, although the winds at the same level may be

very strong.

OROGRAPHIC LIFTING -The lifting of an air current

caused by its passage up and over mountains

OVERSEEDING — Cloud seeding in which an excess of

nucleating material is released. As the term is nor

mally used, the excess Is relative to that amount of

nucleating material which would, theoretically, maxi-

mize the precipitation received at the ground. In

seeding a supercooled cloud with dry ice or silver

iodide, addition of too much seeding material may

create so many ice crystals that none can grow to a

size large enough to fall out of the updraft sustaining

the cloud.

PLUME— The volume of air space containing any of the

substance emitted from a point source.

PRECIPITATION -Any or all of the forms of water

particles, whether liquid or solid, that fall from the

atmosphere and reach the ground

PRECIPITATION ECHO -A Type of radar echo re

turned by precipitation

PRECIPITATION EFFICIENCY — For a given cloud or

storm system, the ratio of the amount of precipitation

actually produced to the maximum amount theoreti-

cally possible by that system.

PRECIPITATION GAGE -General term for any device

that measures the amount of precipitation; princi-

pally, a rain gage or snow gage

PYROTECHNIC GENERATOR -A type of silver iodide

smoke generator in which th^silver iodide forms as

a part of the pyrotechnic fuel mbtture. A great flexi

bility of design is possible with these generators, and

they are capable of an extremely high output of

silver- iodide nuclei.

RADIOSONDE- A balloon borne instrument for the

simultaneous measurement and transmission of mete-

orological data.

RAIN MAKING -Popular and general term for all

weather modification effort aimed at increasing pre-

cipitation.

RANDOM — Eluding precise prediction, completely Ir-

regular. In connection with probability and statistics,

the term random Implies collective or long-run regu-

larity; thus a long record of the behavior of a random

phenomenon presumably gives a fair indication of Its

general behavior in another long record, although the

individual observations have no discernible system of

progression

RANDOMIZE — To make random. Specifically, in weath

er modification contexts, It refers to the design of

experiments and projects In such a way as to mini

mlze the sources of bias in the evaluation of results

by dictating that "seed" or "don't seed" decisions

(for example) be made on a purely random basis

If the total number of such decisions Is sufficient, ■,

large, this procedure ensures that a comparison of

"seed" versus "don't seed" results contains minimal

bias.

REAL-TIME — Nearly Instantaneous.

condensation nucleus.

SALT SEEDING — Cloud seeding with salt particles, a

technique that has been applied to warm (non-super

cooled) clouds and fog on the principle that the hy

groscopic droplets of salt solution will grow at the

expense of other particles.

SEEDING RATE — The quantity of seeding agent (in

grams or kilograms) released either per unit of time

(if applied to ground-based generators) or per unit

of distance (traveled by an aircraft) used in cloud

seeding.

SILVER IODIDE — (Chemical formula: Agl. ) The com

pound of silver and iodine whose crystalline structure

very closely approximates that of Ice-crystals.

SILVER-IODIDE GENERATOR- Any of several de

vices used to generate a smoke of silver-iodide cry

staJs Most burn an acetone solution of silver iodide;

the other Important (and newer) category is that

of pyrotechnic generators.

SILVER-IODIDE SEEDING — The world-wide "work-

horse" method of cloud seeding, where, by any of

several techniques, silver- Iodide crystals are intro

duced into the supercooled portions of clouds to induce

the nucleation of Ice crystals.

SNOW COURSE -An established line, usually from

several hundred feet to as much as a mile long,

traversing representative terrain in a mountainous

region of appreciable snow accumulation Along this

course instruments (such as snow stakes, radioactive

snow gages) are installed, and/or core samples of the

snow cover are periodically taken and averaged to

obtain a measure of Its water equivalent

STRATOCUMULUS-A principal, low-altitude, cloud

type, consisting of a layer of rounded or roll shaped

elements which may or may not be merged and which

usually are arranged in orderly flies or a wave pat

tern.

the solid phase directly to the vapor phase, or vice

746

versa, without puitng through an intermediate liquid

SUPERCOOLING — The reduction of temperature of any

liquid below the melting point of that substance's

eolld phase; that Is, cooling beyond its nominal freez-

ing point A liquid may be supercooled to varying

degrees, depending upon the relative lack of freezing

nuclei or solid boundary irregularities within its en-

vironment, and freedom from agitation.

SYNOPTIC— In general, pertaining to or affording an

overall view.

In meteorology, this term has become somewhat

specialized in referring to the use of meteorological

data obtained simultaneously over a aide area for the

purpose of presenting a comprehensive and nearly

Instantaneous picture of the state of the atmosphere.

Thus, to a meteorologist, "synoptic." takes on the

additional connotation of simultaneity.

TARGET AREA — la a weather modification project,

the area within which the effects of the weather mod-

ification effort are expected to be found

TRACER— An easily detectable substance injected into

the atmosphere for the purpose of subsequent mea-

surement and reconstruction of Its history- (trajectory,

diffusion, etc )

TRAJECTORY— (Or path, t A curve in space tracing

the points successively occupied by a particle in mo-

tion. At any given Instant the velocity vector of the

particle Is tangent to the trajectory.

WARM CLOUD— In weather modification terminology,

a water doud that is not a supercooled cloud La,

that exists entirely at temperatures above 0*C.

WATER EQUIVALENT— The depth of water that would

result from the melting of the snowpack or of a snow

sample.

tore.) Water substance In vapor form: one of the

most Important of all constituents of the atmosphere.

WEATHER MODIFICATION — The Intentional or In-

advertent alteration of weather by human agency.

WEATHER RADAR -Generally, any radar which Is

suitable or can be used for the detection of precipi-

tation or clouds.