storm can be affected, and by how much, by cloud seeding or other modification techniques, that we must have a much larger effort go into this before we can answer that question adequately.

Questions are being put to us now that we can't answer because we really don't have the information.

Senator CANNON. You pointed out in your statement the tools that are used in this work. I noticed you didn't mention computers. Is there any place or what is the place of computers in large-scale experiments of this nature now?

Professor MORDY. Computers are being used very widely as I am sure you are aware, in the field of meteorology and Mr. John Chisholm when he appears before this committee in Elko will describe an engineering approach to the problem of getting adequate information in time to alter your experiment in progress, in a weather modification experiment.

This will involve ultimately an integration of a lot of diverse information into an easily understood pattern of the experiment in terms of plots of meteorological information, radar displays, aircraft positioning, wind data, and so forth.

To do this, I suspect that we will be drawing more and more on small computers to organize this information so we can readily understand it at the time. Large computers have been used in order to—in hemispheric-scale numerical weather prediction problems in such a way by varying various meteorological factors, what happens as a result of some artificial influence can be determined.

Thus far numerical weather prediction isn't good enough so that we could use it as a criterion for the evaluation of a cloud-seeding experiment.

One other application of computers is that we are able to model experiments when they are modification experiments in a mathematical description. In other words, we formulate a theoretical cloud with a certain number of droplets growing and the way they grow in nature, and then we alter the number of ice crystals or the number of condensation nuclei in the problem as we set it up and see what effect this will have on the total development of this theoretical cloud.

So we are using computers as a means of designing experiments which can be adequately tested in the field, and each theoretical model is tested at its most critical point by a field experiment.

Senator CANNON. Do you feel that there is a need for a central registry of all experiments in commercial seeding-type operations? Professor MORDY. I think that every scientist believes that the results of his work must be published and must be open to debate in order to allow those of other views to express their views and to argue the truth of the information which is represented.

In this sense we have journals and have had for many years, in the field of meteorology and geophysics for the publication of such results. I believe that it is very important and I think the National Science Foundation has been doing this for a number of years, to monitor all experiments so that we don't conflict with one another and so that we are aware of progress elsewhere.

So my answer to your question would be "Yes."

Senator CANNON. Most of the testimony today has been on seeding. Is this the sole area of major potential success?

Professor MORDY. Are there other things that we could do that would modify the weather is this the nature of the question?

Senator CANNON. Yes.

Professor MORDY. Well, there are all sorts of things that are within the engineering capability, it seems to me, that can alter weather locally or generally. Often we are sure that it would alter the weather but we don't know just how, and that, of course, makes experimentation very unlikely.

As a case in point, the rainfall in Hawaii on the island of Oahu doubles roughly for each mile and a half you go inland. If you start off at Waikiki Beach and you walk up to the upper end of Manoa Valley and you start off with 15 or 20 inches of rain a year, by the time you walk this distance you could walk it in a couple of hoursyou are at a rainfall of 185 inches.

The maximum rainfall along the Koolau Mountain Range on Oahu is about 300 inches of rain a year. That range of mountains is only about 3,000 feet high and is a ridge roughly perpendicular to the trade winds. There are deeply eroded valleys that run on the leeward side of the mountain range so that there is an abrupt escarpment or amphitheater at the top of each of these valleys.

It would be perfectly possible to bulldoze a "V" in those mountains and allow the tradewinds to escape through the cut. This would dramatically alter the average annual precipitation at the upper end of that valley. I am confident that one couldn't get permission for the State of Hawaii to carry out that experiment but this is a case in point where there isn't any question but that one could alter the climate.

Similarly, it has been suggested by a number of people that one could do something to change the reflectivity of snowfields in the Arctic regions, to change the flow of the ocean currents near the Bering Straits, to dam Gibraltar and let the Mediterranean dry up. These things are feasible from an engineering point of view, but I happen to like the Mediterranean climate the way it is.

This is a case in point as to where we will go when we can alter meteorological conditions.

Senator CANNON. Is there any study being made, for example, of why the recent runoffs here in Nevada and in the Colorado River Basin were very, very low?

Professor MORDY. Not as such. These are not atypical of longrange weather variations. Thus you could make a census of the number of storms that came in or the shifting patterns of the world weather patterns on the hemispheric weather charts. All these things would show not a cause but a relationship between the weather here and the weather somewhere else.

This is part of this meteorological noise in the system which I indicated in my statement.

Senator CANNON. I was going to ask you about that. What do you mean by "noise"? You say, "The noise in meteorological data is large."

Professor MORDY. One refers to systematic variations in science as things one could detect and describe whereas unsystematic variations have recently been described in science as noise in a systemsomething in which one is not able to sort out any systematic varia

tions. Because there are so many variables in the weather, all changing with time, when one sets out to measure one variation in precipitation resulting from one part of an experiment, it is very difficult to sort that influence out from all the other influences on the weather.

Senator CANNON. Do you think that seeding in one area is likely to reduce precipitation in another?

Professor MORDY. Not at our present stage of experimentation. If we ever reach the point, as Dr. St. Amand may tell you here, where we can seed huge areas of the globe, then it may very well affect it, but at the present time on the scale that we are experimenting I think it is very unlikely that one could show any influence a hundred miles or even less downwind from the experimental area.

Senator CANNON. In other words, in a certain cloud system is the seeding activity going to take a rain or snow that would otherwise fall someplace else, or is there going to be a net increase?

Professor MORDY. If I could second-guess you on this I would say that the answer I would like to give you without qualifications is "No." It isn't a matter of taking water away in this case because as I indicated, the amount taken out is a relatively small amount of the total amount there so the amount removed would be almost undetectable. But there are the possibilities downwind that if seeding is done without the knowledge of all concerned and not watched by the public, that large amounts of seeding agents could drift long distances downwind and confound other experiments of affect weather downwind this way.

Senator CANNON. You indicated you thought that not enough effort was being devoted to this field.

Approximately $6.9 million is being spent in this area this year. What do you feel actually is needed?

Professor MORDY. We have estimated that an expenditure within 3 to 5 years of $20 million a year by the Federal Government, concentrated in a relatively few experiments, would get at the engineering problems that I was talking about earlier.

Senator CANNON. Why does weather modification represent such a small percentage of the efforts in this area of atmospheric science at the present time? Is it because of the controversies that have existed? Professor MORDY. To some degree; yes.

I think that the science of meteorology is a little different from a laboratory science. We have people working as practicing meteorologists who never make observations, who never go outside the room where the computer is.

We have other people who collect observation information and never see the use that is made of it. We have a large number of meteorologists who are members of the American Meteorological Society. A large number of them are employees of the Federal Government.

This means that a great body of opinion in our field is represented by people who are highly specialized in their work and never actually become involved in experimental work. This I think is one reason why it has been hard for the relatively few to be heard among those who are skeptics and who have not been involved in the experimental programs.

Senator CANNON. Your observation that many of them never look at the instruments and never see what the weather is actually like is reminescent to me, as a pilot in most recent years, when very frequently there was a saying among pilots that you get a weather report but the best way to tell is to ask the meteorologist to look out the window and tell you what he sees.

Is there a possibility of overseeding clouds that would produce any bad effects?

Professor MORDY. If you overseed a cloud, the probability is that you won't get any precipitation from it. If you overseed a cloud that might form hail you may prevent large hailstones from developing. This is the basis for that work.

If you overseed a cloud in which thunder and lightning are likely to occur, there are those who believe that you may change the electrical fields around the cloud and diminish the possibility of lightning and forest fires.

Senator CANNON. In other words, the experimental areas of lightning and hail damage and violent storms is being approached from the standpoint of overseeding rather than normal or underseeding?

Professor MORDY. Yes; or changing the cloud from a water cloud of supercooled water droplets to a cloud of ice crystals which won't collect in these large hailstones for example.

Senator CANNON. What is the difference in supercooled and the terminology that is used?

Professor MORDY. We broke the rain-forming mechanism really into two models. In clouds which never reach the freezing level, tropical clouds in which large amounts of rain form, it is believed that precipitation due to the natural variations in vertical velocity, the number of salt particles, on which cloud droplets form, and to the different droplet growth rates which occur with different naturally occurring conditions.

This is called warm cloud. That is, all of the cloud is warmer than freezing.

In supercooled clouds, the objective when one uses dry ice or silver iodide or some other seeding agent is to affect the number of ice crystals present with droplets which are already colder than freezing. Water won't freeze at 32° F. (0° C.) if it doesn't have some impurity in it or isn't disturbed in some way.

A great many clouds are made up of water droplets colder than freezing. When you put in ice crystals you completely change the character of the cloud. So a supercooled cloud is a cloud made up of droplets colder than freezing.

Senator CANNON. And there are only then, obviously, certain types of clouds that you can have success with in a seeding-type operation? Professor MORDY. Yes.

Senator CANNON. What are the legal and social implications, if any, of the work being carried on, for example, at Desert Research Institute in this weather modification program?

Professor MORDY. I am not qualified to talk about the legal implications in weather modifications or the social implications. I intended to infer that when I was talking about these other ideas for weather modification of weather and climate of large geographical areas.

Senator CANNON. Do you have someone in the organization who is qualified in this field who could perhaps submit a statement to us?

59-528-66-pt. 1- -3

Professor MORDY. We have a consultant whose name is Edward Morris, of San Bruno, Calif., who is perhaps the most knowledgeable person on the legal implications of weather modification. He has an article in the current issue of the Bulletin of the American Meteorological Society (October 1965).

Senator CANNON. We would be very happy to have him appear at our hearings in Washington which will resume early next year. We will be holding rather extensive hearings there.

Now, Professor, as I understand it, do you want us to have these pictures here that you talked from? If so, they will be made a part of the record, or would you be willing to reproduce those and give us a copy?

Professor MORDY. It is probably easier to put them in a booklet form for you.

Senator CANNON. If you would do that and put the same identification that we talked about for the record here today because I think we have them very well identified with those two particular experi

ments.

Mr. CHISHOLM. Would you like a copy of the film, Senator?

Senator CANNON. I would doubt that. If you have any still pictures with a legend on them it would be helpful, from the results of the experiment, we would be delighted to have those.

But it is very difficult for us to use a film effectively before the committee.

Do you have anything further to add, Professor, on this subject? Professor MORDY. I don't think so.

Senator CANNON. I want to thank you for your appearance here. It has been most helpful to us.

We will now stand in recess for 10 minutes and then resume the hearings.

[Recess.]

Senator CANNON. The next witness will be Mr. Joseph Warburton, from the Desert Research Institute. Mr. Warburton, we are very happy to have you here. You may proceed, sir.

STATEMENT OF JOSEPH WARBURTON, DESERT RESEARCH INSTITUTE

Mr. WARBURTON. Senator, I am a senior research scientist of the Commonwealth Scientific and Industrial Research Organization of Australia, and I am presently on 2 years' leave to occupy a position as a research associate at the Desert Research Institute at the University of Nevada.

As a Commonwealth officer of Australia, I must point out that the views I am expressing are my own, and not necessarily those of the organization to which I belong. I have been engaged in the field of cloud physics in our organization for a period of 6 years, and this work has been principally along the lines of designing physical and chemical types of experiments which can be used in the interpretation of weather modification results.

I have had experience in five large-scale weather modification experiments in Australia, the first of which began in 1955 and lasted for 5 years. Another one lasted for 6 years. Two of them lasted

for 3 years, and one of them lasted for 2 years.