Science, and transportation united states senate

the present use of weather modification technology: however, such

policies cover a wide spectrum, some being highly restrictive while

others are more permissive. This study, focusing on decisionmaking

processes in five States — South Dakota. Colorado, Illinois, Pennsyl-

vania, and California — will develop case histories and analyses of

policymaking, the availability of which should help Federal and State

officials in making decisions on emerging weather modification

technology. 83

Agricultural iceather modification

This relatively new portion of the NSF/RANN weather modifica-

tion program is* evolving in response to a need "to develop a better

understanding of weather variability and its significance to food pro-

duction and to develop specific applications of weather modification

technology as it relates to agricultural needs. 84 For such applications,

weather modification is considered in a broad context, including all

identifiable modifications of the atmospheric environment.

» National Science Foundation. Division of Advanced Environmental Research and Tech-

nologv, "Summary of Awards : 1976," p. 101.

81 Ibid., p. 102.

w National Science Foundation. Division of Advanced Environmental Research and Tech-

nology. "Summary of Awards: Transition Quarter 1976." NSF 77-8. Washington, D.C.

(no publication date) , j). 48. _ . , _ . . ,-__«,

«• National Science Foundation. Division of Advanced Environmental Research and Tech-

nology, "Summary of Awards : 1976," p. 105.

289

A major study, which included an assessment of the potential of

pleted by the National Academy of Sciences (NAS) /National Re-

search Council. The investigation dealt with changing weather and

climate patterns and their effects on agricultural and renewable re-

sources productivity. 85 These implications were examined by the com-

mittee in climate and weather fluctuations and agricultural produc-

tion, which was established by the NAS in June of 1975 at the request

and with the support of the National Science Foundation. Among

other considerations, a chapter of the committee's report was devoted

to weather modification, covering such topics as the feasibility of

weather modification, crop-weather relationship and weather modifi-

cation, impact variability, and societal and environmental issues. The

committee made the following recommendations : 86

Intensive efforts should be made to apply existing basic knowl-

edge of atmospheric and cloud processes in specific applied re-

search programs to benefit agriculture. Methods of applying the

benefits of demonstrated or nearly demonstrated weather modi-

fication techniques to specific crop needs, incorporating water

storage, and other water management procedures, should be devel-

oped. Proper recognition of societal concerns must be included.

Gaps in basic knowledge of agriculturally oriented weather

modification should be identified, and research initiated to fill

them. Results of this research should be applied on an interactive

basis with ongoing research and application projects. Important

segments of the basic research should address the exploration of

new ideas and approaches.

Government organizational structures and policies should in-

sure an integrated approach to weather modification research so

that related problems such as rain and hail from convective sys-

tems can be treated in the same experimental framework. Research

programs should be interdisciplinary, should draw on the expertise

available from Government agencies and from the academic and

private sectors, and should incorporate a productive mix of big

science — permitting large, pooled facilities — and small science —

encouraging small group initiatives. The growing collaboration

between scientifically and operationally oriented weather modi-

fication experts should be focused on key crops and agricultural

regions.

Two other recent NSF-sponsored research projects on weather modi-

fication in support of agriculture are:

1. An assessment of the present and potential role of weather modi-

fication in agricultural production, conducted by Colorado State Uni-

versity. This research was intended to identify potential capabilities of

weather modification in terms of agricultural productivity and to

focus priorites for weather modification research in terms of maximum

benefits to agriculture. The research plan included a workshop of ex-

perts in agriculture and weather modification in order to develop an

authoritative document on the role of weather modification in increas-

ing world agricultural production. 87

83 National Academy of Sciences, National Research Council, "Climate and Food ; Climate

Fluctuation and U.S. Agricultural Production." a report of the Committee on Climate and

Weather Fluctuations and Agricultural Production, ISBN 0-309-02522-2, Washington,

D.C., 1976. 212 pp.

86 Ibid., p. 131.

87 National Science Foundation. Division of Advanced Environmental Research and Tech-

nology, "Summary of Awards : 1976," p. 105.

290

2. Assessment of weather modification in alleviating agricultural

survey. The purpose of this study was to provide information needed

in decisionmaking processes regarding use of weather modification for

mitigation of agricultural droughts in the Midwest and other similar

areas. This research was intended to contribute to man's knowledge of

the limitaitons of weather modification to planned precipitation aug-

mentation for agricultural applications and to assist in determining the

scope and duration of future weather modification research in similar

climatic regions of the world. 88

DEPARTMENT OF COMMERCE

Introduction and general discussion

Within the Department of Commerce the research program in

weather modification is conducted by the Environmental Research

Laboratories of the National Oceanic and Atmospheric Administration

(NOAA). Through NOAA's predecessor organizations, the U.S.

Weather Bureau and the Environmental Science Services Administra-

tion (ESSA), the Commerce Department has been active in weather

modification since 1946, with research programs directed at modifying

severe storms such as hurricanes, increasing rainfall from tropical

cloud systems, and suppressing lightning in thunderstorms. The two

major ongoing research projects are the Florida Area Cumulus Ex-

periment (FACE) , a project to demonstrate the possibility of increas-

ing precipitation from convective cloud systems through dynamic seed-

ing, and Project Stormfury, intended to mitigate the severe impacts of

hurricanes.

The NOAA Research Facilities Center (RFC) , is an operational and

technical organization, with the mission of providing instrumented air-

craft for research programs of NOAA and other Government agencies,

including weather modification projects. Part of NOAA's overall

weather modification effort is its program of Global Monitoring for

Climatic Change (GMCC), under which measurements are made of

natural and manmade atmospheric trace constituents in order to deter-

mine their increases or decreases and possible influences on climatic

change. Other research in recent years has been concerned with modi-

fication of extratropical severe storms and in suppression of lightning,

the latter in cooperation with the National Aeronautics and Space Ad-

ministration (NASA) in connection with protection of launch vehicles.

In addition to these activities intended to explore weather modifica-

tion and develop techniques for controlling the weather, NOAA also

conducts background research in a variety of areas of atmospheric sci-

ence that is essential to the future of weather modification development.

Included are modeling and theoretical work on the structure, dynamics,

and energy processes of severe storms such as hurricanes, tornadoes,

and thunderstorms. Also pertinent is the development of instrumenta-

tion for direct measurement of atmospheric properties and for remote

probing of the atmosphere. 89

A summary of the funding for the NOAA weather modification

program for fiscal year 1976 through fiscal year 1978 (estimated) is

contained in table 15.

88 Ibid., pp. 105-106.

w Townsend, John W., testimony In : U.S. Congress. House of Representatives, Committee

on Science and Technology. Subcommittee on the Environment and the Atmosphere, "Weath-

er Modification," hearings. 94th Congress, 2d session, June 15-18, 1977, Washington, D.C,

U.S. Government Printing Office, 1976, p. 171.

291

TABLE 15. — WEATHER MODIFICATION FUNDING FOR FISCAL YEAR 1976 THROUGH FISCAL YEAR 1978 FOR THE

[In thousands of dollars]

Fiscal year—

1976

1977

870

735

Modification of convective clouds

Research facilities center (prorated)

755

171

757

893

Subtotal

4,304

632

2,703

Air quality analysis

1,717

313

76

346

160

2,030

1,909

6, 334

4, 577

> From Federal Coordinating Council for Science, Engineering, and Technology. Interdepartmental Committee for Atmos-

pheric Sciences. National Atmospheric Sciences Program: Fiscal Year 1978. ICAS 21-FY 78. August 1977, p. 89.

NOAA 1 X-band Doppler radar operated by the Wave Propagation Laboratory

of the National Oceanic and Atmospheric Administration. (Courtesy of the

U.S. Department of Commerce.)

The Florida Area Cumulus Experiment {FACE)

The FACE program is conducted by the cumulus group of NO AA's

National Hurricane and Experimental Meteorology Laboratory

292

individual clouds were seeded in Florida. These experiments demon-

strated that dynamic seeding 90 is effective in increasing the sizes and

lifetimes of individual cumulus clouds and the rainfall resulting from

them. FACE is designed to determine whether dynamic seeding can

be used to augment convective precipitation over a large area in south

Florida by promoting the development of larger, better organized

convective systems. Cloud merger, the joining of two formerly inde-

pendent cloud entities, appears to be the important natural process

leading to heavy and extensive rainfall in Florida. 91

The design of FACE was intended to investigate two sequential

questions. The first question was whether dynamic seeding can be used

systematically to induce cloud merger and increase rainfall from the

groups of subject clouds, and the second was to determine whether

dynamic seeding can be used to produce a net increase in rainfall

over a fixed target area. An affirmative answer to the first question,

while necessary, may not be a sufficient condition to verify the second. 92

FACE has been an exploratory experiment intended to answer these

questions; hence, its design has been evolutionary. It cannot, there-

fore, be regarded as a conclusive experiment, in spite of strong indica-

tions of a positive seeding effect, it must be replicated with

a predetermined design to confirm results achieved to date. It is

planned that such a confirmatory FACE effort will begin in Florida

during the summer of 1978. 93

The experimental design for FACE is a random design, where the

days over a single target are randomized into seeded and nonseeded

days, with nonseeded days as the control. Experiments began on a

limited basis in 1970 and were continued in 1971, 1973, 1975, and 1976.

Design features included : 94

1. A fixed target area with the experiments randomized by day.

2. Surveillance of the clouds in the target by 10-centimeter radars,

with radar estimation of the rainfall (rain estimates were adjusted

using rain gages) .

3. Determination of suitable experimentation days on the basis of

a daily suitability criterion, based on predicted cloud heights for

seeded and nonseeded conditions, using a one-dimensional cloud model.

A factor was also introduced to bias the decision for suitability against

natural rainy days.

4. Flights by seeder aircraft on days that satisfy the suitability

criterion. The decision to seed was randomly determined in the air,

with only the randomizer knowing the decision. Suitable convective

clouds were seeded near their tops.

5. Final acceptance of a day for inclusion in the analysis only if 60

flares were ejected or six clouds were seeded, or both.

90 For a discussion of dynamic seeding of cumulus clouds see ch. 3, p. 68.

91 Woodley, William L., Joanne Simpson, Ronald Biondini, and Joyce Berkeley, "Rainfall

Results, 1970-75 : Florida Area Cumulus Experiment," Science, vol. 195, No. 4280, Feb. 25,

1977. p. 735.

92 Ibid.

93 Woodlev, William L., J. A. Jordan, Joanne Simpson, Ronald Biondini, and Jobn A.

Flueck. "XOAA's Florida Area Cumulus Experiment. Rainfall Results; 1970-76" (Sub-

mitted for publication to the Journal of Applied Meteorology.) 1978.

9 * Woodlev. Simpson. Biondini, and Berkeley, "Rainfall Results, 1970-75 : Florida Area

Cumulus Experiment," 1977, pp. 735-736.

293

In the analysis of the FACE experimental days, floating target

the initial seeding. The floating target is composed of the radar echoes

of all experimental clouds and those with which they merge. The

total target is made up of the floating target echoes plus the echoes of

nonexperimental clouds. 95

Figure 13 is a map of the field design for FACE, showing the

Figure 13.— Field design for the Florida Area Cumulus Experiment (FACE).

The largest quadrilateral is total target area, within which are areas covered

by the dual Doppler radars, the mesonet intensive network and the clusters of

rainguages. (From Woodley and Sax, NOAA Technical Report ERL 354-WMPO

6, January 1976.)

85 Woodley, William L. and Robert I. Sax, "The Florida Area Cumulus Experiment : Ra-

P e ?J g «?' Procedures, Results, and Future Course," NOAA technical report ERL 354-

WMPO 6. U.S. Department of Commerce, National Oceanic and Atmospheric Administra-

tion, Environmental Research Laboratories, Boulder, Colo., January 1976 p xiv

294

rain gage coverage, as configured in the period 1972-73. Although

the basic target area remained the same, the networks of intensive

coverage by radar and rain gages were modified somewhat in later

years.

Data from 75 experimental days have been accrued in FACE since

have shown that dynamic seeding under appropriate atmospheric con-

ditions is effective in increasing the growth and rain production of in-

dividual cumulus clouds, in inducing cloud merger, and in producing

increases in rainfall from groups of convective clouds as they pass

through the target area. When rainfall over the total target area (i.e.,

that from the floating target plus that from nonexperimental clouds

within the target area) is averaged, a net increase also seems to result

from seeding. 96

The following specific results of the experiment from analyses to

dato have been summarized by Woodley, et al. : 97

The many overall and specialized analyses presented in this paper lead to the

strong indication that dynamic seeding increased areal rainfall in FACE, by

altering convective processes on the mesoscale and promoting cloud merger.

Rainfall in the floating and total targets was greater in the mean (about 50 per-

cent in the floating target and 25 percent in the total target), and the standard

deviation (50 percent in the floating target and 40 percent in the total target) on

seed days than on control days.

The authors continue, discussing the physical basis for confidence : 98

Although FACE has been an exploratory effort with an evolving design, one

can have considerable confidence in the interpretation of the outcome. Increases

of seeding effect based on rain gage measurements agree with those based on

gage-adjusted radar. The microphysical measurements within seeded clouds

provide clear evidence for anomalous glaciation relative to their unseeded counter-

parts. * * * The time-dependence of the seeding effect and its dependence upon the

number of flares expended are consistent with an effect of seeding.

In fiscal year 1977, FACE activities have included a thorough anal-

ysis of available experimental data and additional research in order to

establish the physical basis for FACE rainfall results. During fiscal

year 1978 there will be further analysis of data and results obtained

from field programs in order to solidify, both physically and statisti-

cally, the encouraging preliminary results, showing a rainfall increase

over the entire 13,000 km 2 experimental area on seed days versus non-

seed days. 99

The implications of this work to the needs of hydrology and agricul-

ture demand that it be continued and expanded. A confirmatory dy-

namic seeding effort will be conducted in an area where there is both

need and a favorable meteorological and societal climate for such a

program. 1 Preliminary studies are underway to identify possible addi-

86 Woodlev, William L., Joanne Simpson, Ronald Biondini. and Jill Jordan. "NOAA's

Florida Area Cumulus Experiment ; Rainfall Results. 1970-76." in preprints from Sixth

Conference on Planned and Inadvertent Weather Modification. Champaign-Urbana, 111.,

Oct. 10-13. 1977. American Meteorological Society. Boston. 1977, p. 209.

87 Woodlev. Jordan. Simpson. Biondini. and Flueck, "NOAA's Florida Area Cumulus Ex-

periment ; Rainfall Results : 1970-1976." 1978.

M Ibid., p. 58.

98 Federal Coordinating Council for Science. Engineering, and Technology. Interdepart-

mental Committee for Atmospheric Sciences. "National Atmospheric Sciences Frogram :

Fiscal Year 1978," ICAS 21-FY 78, September 1977, p. 88.

1 Woodlev. Simpson, Biondini. and Jordan, "NOAA's Florida Area Cumulus Experiment;

Rainfall Results, 1970-76," 1977, p. 209.

295

range objective of the program is to make the technology developed in

Florida available to otlier areas in the United States which are charac-

terized by periods when most of the rainfall is provided by convective

showers.

Preliminary plans have been developed to conduct a summer cumu-

lus experiment, along the lines of FACE, in the cornbelt of the Mid-

west, in an attempt to determine the transferability of the FACE

results. A very suitable region for such a field experiment appears to

be in central Illinois, and plans for the proposed Precipitation Aug-

mentation for Crops Experiment (PACE) have been concentrated on

this area, whose location is shown in figure 14. 2 Initial plans for the

Figure 14. — Map showing the location of the target area for the proposed precipi-

tation Augmentation for Crops Experiment (PACE) (from Ackerman and Sax,

1977).

Note. — Shown for each State is its 1975 value of farm products in billions of dollars, and

2 Ackerman, Bernice. and Robert I. Sax. precipitation augmentation for crops experi-

ment (PACE), presentation to the U.S. Department of Commerce Weather Modification

Advisory Board, Champaign, 111.. Oct. 13, 1977.

296

meteorological program are being developed by the Illinois State

been indicated by scientists from four midwestern universities, the

University of Virginia, and the NHEML. A four-stage experiment is

now contemplated, which could extend over a 9- to 13-year span, with

costs ranging from $8.5 to $10.5 million. 3

Project Stormfury

NOAA's largest effort in weather modification has been Project

Stormfury, conducted by the National Hurricane and Experimental

Meteorology Laboratory (NHEML) and aimed at developing methods

for moderating the most destructive peak winds in hurricanes. The

project is designed to investigate the structure and dynamics of tropi-

cal cyclones and their potential for modification. The range of activi-

ties under Stormfury includes development of mathematical models ;

theoretical and diagnostic investigations and calculations; field re-

search on hurricane structure, variability, and dynamics ; and actual

hurricane modification experiments. 4

The earliest known hurricane modification attempt occurred Octo-

ber 13, 1947, when General Electric Co. scientists and technicians,

under Government contract, dropped dry ice into the thin, stratified

clouds outside the walls of a hurricane east of Jacksonville, Fla.

Equipment suitable for monitoring the structure, intensity, and move-

ment of the storm during this operation was not available ; however,

some localized changes in the thin-layered cloud were noted by visual

observation. Subsequent studies indicate that this operation could have

had little effect on the storm. The experiments from which the present

project evolved began in 1961, though Project Stormfury was formally

established in 1962 as a combined program of the Department of Com-

merce (Weather Bureau) and the Department of Defense (Navy).