is one of the areas that needs the kind of cooperation you are talking about. It is also needed in the middle country area, Nebraska and Iowa. They all have problems of a similar nature.

The pollution we get is not all urban. We get pollution from Denver moving eastward, from New Orleans moving north, and so on. We need to begin to spread out. I think that this is the ideal mechanism. The Bureau of Reclamation at the present time-I am probably going to miss some have programs at the University of Nevada, at Wyoming, at the South Dakota School of Mines, at Utah State, and a number of small programs are being supported now. Obviously when you get that kind of support indicated and you have good outdoor laboratories in the region those of us in the East and those in the West are certainly going to go where the projects are. In fact that is where I spend my summers. I spend my summers in Arizona and Colorado because this is the place where the weather problems of the East arise. I take a good many of my students there. So you have a marvelous opportunity with this very bill to get back to smaller college projects and the Department of Interior, through the Bureau of Reclamation, recognized this and already has a good program going.

I think more of these types of projects, not only in weather modification but in water resources and air pollution control through the Public Health Service, and other agencies, is a very logical thing. I believe it has tremendous potential for the smaller States.

Senator CHURCH. Did you think this imbalance can be adequately corrected without new legislation?

Dr. SCHAEFER. I think it is very necessary to consider this very carefully. I think S. 2875 is a move in that direction. I am sure that the present wording will be modified as you take all the evidence that we are trying to present to you and out of it I hope an outstanding new look will come.

I think that there are tremendous possibilities here that everyone will be very happy about if the job is done right. We are here to really try to help you.

Senator CHURCH. Thank you.

Senator ANDERSON. The Senator from Arizona.

Senator FANNIN. Thank you, Mr. Chairman.

I would like to ask Dr. Schaefer a question. First of all I want to thank you for bringing Arizona and the Colorado River into this discussion. They are very dear to my heart.

We have had a program of weather modification which has been carried on for some years and no doubt will cover what is being done. I am wondering if we are disseminating the information that should be sent out to all the different groups working on these programs. For instance the Salt River project at Phoenix has been doing extensive work on this program for years and years. I remember years ago when they were seeding clouds with silver iodide they used a propane gas furnace to do this with.

At the same time I realize they have stayed on one program. I am just wondering if this is the manner in which this has been handled throughout the country. In other words, have we really disseminated our information properly?

Dr. SCHAEFER. To a certain degree we have in that the community is still so small that when we get together we know everybody by his

first name. This involves even our friends abroad. We just had a meeting of this general kind in Tokyo last May. We have another one coming up on condensation nuclei at our university in another month or so, in May.

The operation at Flagstaff, for example, is now becoming a focal point where we are encouraging people from all parts of Arizona, New Mexico, and other States to come in and see what is going on and join the operation if possible.

I feel that this kind of operation rapidly will get more and more interaction between everyone interested. The National Science Foundation is supporting a hail study this summer at Rapid City, S. Dak. Something like 18 or 20 groups are joining hands to work together for a month.

That means that we are going to be eating and discussing problems and everything else with each other and finding out how others think about our ideas and talking over the problems we have as to whether or not the things we are planning to do have any sense to them. So I think that we are rapidly developing a very good cooperative activity.

Senator FANNIN. Very fine. Thank you.

Senator ANDERSON. Thank you very much, Dr. Schaefer.
Dr. SCHAEFER. Thank you, Mr. Chairman.
Senator ANDERSON. Dr. Bigelow.

STATEMENT OF D. JULIAN H. BIGELOW, PERMANENT MEMBER, SCHOOL OF MATHEMATICS, INSTITUTE FOR ADVANCED STUDY, PRINCETON, N.J.

Dr. BIGELOW. Senator Anderson, members of the subcommittee, the opportunity to appear before this committee of Congress in connection with the problems of weather modification is for me an agreeable study.

I would like first to emphasize that though I was a member of the National Academy Panel and also have had some prior contact with problems arising in the atmospheric sciences I am not a career meteorologist but an applied mathematician with a background in calculational procedures, computing machines, instruments, and methods of experimental measurement, and statistical evaluation of physical phenomena.

During the last 2 years while a member of the Panel, I have made a substantial effort to understand the problems, and present state of weather modification and whatever merit the information I may contribute can have is primarily that of an unbiased scientist looking at these problems from a neighboring field.

To give good scientific counsel to those charged with the responsibility for legislative support of scientific and technological effort, I think it is important to try to gage realistically the facts of the situation, and to estimate the likely and unlikely outcomes. Because weather modification can be viewed as a broad topic, including many important aspects such as violent storms, lightning, atmospheric pollution, and so forth, I shall restrict my remarks hereinafter specifically to weather modification for the purpose of influencing precipitation. The primary tool which is available today for influencing precipitation is cloud seeding by silver iod de; this is essentially the same tool

introduced by Langmuir, Schaeffer, and Vonnegut for this purpose some 20 years ago.

During this interval, cloud seeding has had its ups and downs related to periods of apparent success and failure in field experiments. As a precipitation influencing tool, its effectiveness has been continually defended and supported-one might say, stubbornly-by individuals and small teams of cloud seeders, some of them commercial operators. Its use as a tool in scientific investigation of the processes of cloud physics has been pursued by researchers in Government agencies, and under NSF sponsorship and others.

At the present time, there has occurred a remarkable shift in attitude regarding the practical capabilities of this seeding tool to produce increased ground precipitation. So to speak, until a short time ago, the betting odds were against it, now the betting odds are predominantly in favor of some modest but positive success.

The catalyst which caused this shift was not a new and clearer theoretical insight into precipitation mechanism or seeding effects, it was a steady bombardment by these "stubborn men," using empirical facts and experimental data as missiles.

Though the reliable evaluation of the credibility of these data by means of statistical tools has been difficult to the point of despair, it is nevertheless true that the results of such painstaking evaluation of enough raw experimental data have shifted the betting odds. One may say that though scientists pursue a lifelong love affair with theory, those that survive in applied fields learn to recognize and bow to the power of crude facts and data.

us.

We call attention to this situation here and now because we believe it has important implications bearing on the practical problem before What we now believe to be the favorable betting odds were not widely recognized and accepted during the last 20 years because the effects which could be produced by seeding were small compared to the prevailing natural variations in atmospheric precipitation.

Therefore, it is safe to say that until we better understand modification tools and their interaction with the vagaries of the atmosphere, the results that may be expected will probably be scattered and irreg ular-though not necessarily economically insignificant.

A second implication is that for the near future considerable emphasis should be given in any modification program to a close cycle consisting of well planned field efforts, systematic and careful evaluation of results, leading to even better planned field efforts.

I might add that these may well be carried out by men stubborn in their conviction that they will be found right in the end, and propelled by an intimate contact with the human needs involved.

As I see it the weather modification to influence precipitation canat this time and perhaps for the next 5 to 10 years-be viewed as requiring two different levels of effort: one consisting of a cluster of local efforts, and the other directed at more global objectives in time. and space.

The local effort, for which the above close coupled experimental team would, in my opinion, play a key role, would aim to trigger relatively local instabilities in the atmosphere by diligent and locally tailored modification tools such as silver iodide seeding.

It is well known that unless the atmosphere in a local region is already close to precipitative instability, seeding cannot have signifi

cant effect on precipitation. For this reason, the local modification effort is subject to the whims and variations of large scale meteorological phenomena such as the general circulation, until such a time as we are able practically to modify such large scale efforts.

Consequently the local team cannot be expected to increase precipitation, when, where, and as needed; they will have to be prepared to exploit as best they can the opportunities that chance to come their way. This implies that a flexible and opportunistic approach will be needed, and also for the near future ground management of water will play a key role in conserving and making available the economic benefits that may accure from whatever leverage we presently or within the near future are likely to have.

Thus a near term national program of precipitative weather modification would, in my view, consist of a checkerboard of such local team efforts, each doing the best and most realistic job possible in the associated region.

There is no reason to believe that, for the near future, the techniques and procedures best suited to one region will prove best in another region, so that a unified procedure and comprehensive theory may, for the time being, be unattainable.

However, for all local teams new and powerful instrumentation systems for detection observation, measurement, and evaluation will become necessary, in order that opportunities to modify be properly identified and the outcome evaluated.

In effect, the goal of this instrument system can be viewed as being capable of generating continuous maps whose contours shows the degree of nearness of the state of the atmosphere to modification responsive instability. To accomplish this would require a major, coordinated research and development effort and the large scale data inflow to the instability mapping system would best come in large measure from the Weather Bureau data gathering, forecasting, and general circulation facilities.

Much research and development would be required to make even such an interim operational effort effective. New instruments and particularly dense local observing and calculating systems would have to be developed; also improved modification agents and methods of dispensing them and particularly important new experimental and evaluative techniques for field use. Thus even the local program requires substantial backup in the form of laboratory studies, conceptual analyses, and systems development.

Turning now to a broader and more long-range view of the precipitation modification program, there are many avenues to explore wherein too little is known either in theory or by experiment to permit estimating the prospects. For example, it is known that local instabilities are not the only class and perhaps not even the most important class of instabilities with respect to long-range prospects for precipitation modification; there are in fact known to be instabilities in the general circulation which, if means could be found to influence them, might dwarf the influence for silver iodide seeding on a local scale. A correspondingly impressive possibility resides in the influence of high altitude layers upon radiation exchange extending over vast areas.

On a more modest scale, such basic empirical facts as the distribution of natural nucleants in the atmosphere and their correlation with airborne water transport should better be known. Many other scientific

61-553-66

questions of great practical significance can be listed, quite a few of them being within reach of our present technique.

For these problems and aspects of weather modification I would urge that continuing and expanded effort in the atmospheric sciences should be strongly supported, via NSF, ESSA, and other academic and Government teams.

The more immediate and mission oriented weather modification efforts that we have described as local can and must benefit through scientific knowledge relevant to the atmosphere gained from collaboration and cooperation from every possible source. In many fields and over long spans of time, experience has demonstrated that research and development knowledge is seldom fruitless.

I would like to emphasize that the splitting of the precipitationmodification task into two parts, one local and one near term and the other large scale and more long range which was done for purposes of aiding discussion, is not intended to imply an antithesis between practice and analysis, or between experimentalists and theoreticians.

Rather it is intended to emphasize that two different but complementary missions in precipitation modification could well be carried out in parallel, just as in meteorology there has been a tradition for both synoptic and large-scale mathematical forecasting.

It is a fact that the theoretical insights in each of these areas can and have contributed vitally to the other. As has been indicated, the study of local phenomena such as instabilities can greatly benefit from knowledge of large-scale phenomena such as the Weather Bureau have become increasingly skillful in calculating by means of mathematical models.

But a corresponding fact, not often brought out clearly, is that these large-scale calculational models at present simulate local thermodynamic instability phenomena by averages and other quite gross approximations, and it is exactly to observe and model these that the local dense instrumentation system recommended above are intended. Thus it may quite possibly turn out that important information can be exchanged.

In conclusion may I say that I would strongly support appropriate legislation along the lines of S. 2875 which appears well suited to advance this important field.

Thank you, Mr. Chairman.

Senator ANDERSON. Thank you, Dr. Bigelow.

You label yourself as an applied mathematician. As such, having knowledge of the computational problems of weather modification, what role do you think computers can and ought to play in this field?

Dr. BIGELOW. I think they can play two different roles, one of which they have not, up to date, played as effectively or as much as I think they should. That role is to take part in an observation system and to compute a probability, depending upon the number of illogical phenomena measured by observing instruments; the probability that the atmosphere is now in a certain state of instability.

In other words, I am suggesting a role which has not been recognized or implemented; to have in the field measuring observing systems, something which continually computes from the parameters we are able to observe, the instability properties of the atmosphere in respect to modification effects.