ing effects to other areas having different cloud climatologies and terrain features.

The evaluation of the San Juan project revealed an important defect in the project design. The use of a 24-hour time block as an experimental unit forced the decisionmaking of the project into such blocks, and this meant that forecasts of such items as cloud top temperature had to be made for up to 24 hours ahead. The state-of-the-art of forecasting in such detail is inadequate; hence, many experimental days contained many hours each of cloud conditions which were susceptable to overseeding. Therefore, from the viewpoint of the 24-hour experimental day analysis, no significant effects were detected, there being sufficient mixing of overseeding with proper seeding to nullify the 24-hour net effects of seeding. It was only in the post-hoc evaluation of the details of shorter parts of the record that the aforementioned significant variations in seeding effects with different types of clouds were found.

A reduction in the duration of the experimental time block does not necessarily remedy the situation imposed by the forecast problem because with shorter blocks contamination between blocks becomes a problem. An improvement in the monitoring of physical data from the project could overcome this though, and would also sharpen greatly the evaluation. It is worthwhile pointing out that the forecast problem is minimized in the conventional operational program involving no randomization because operational decisions and changes in, or shut down of operations, can be made at any time on the basis of observed weather changes.

A number of randomized projects have been carried out during the past 10 years in the Dakotas by, or under the surveillance of, the Institute of Atmospheric Sciences of the South Dakota School of Mines. Some have contained rather elaborate weather radar observing tools, as well as raingage networks. Numerical models for cumulus clouds have been developed and used extensively in these projects. The models enter into both operational decisionmaking and evaluation of results. Considerable study of seeding effects on cumulus have also been carried out by NOAA in Florida.

There has also been an expansion over the last 10 years of operational seeding in the Dakotas and elsewhere in the high plains. Statewide programs for participating counties are conducted by private firms under contract to State entities. These programs involve the use of fleets of aircraft piloted by especially trained personnel guided by weather radars manned by radar meteorologists.

What is needed to organize a national effort in exploiting the potential of weather modification? In my opinion we should organize a few well run field research projects where the data collected are more numerous, more reliable, and more sophisticated than has been the case heretofore. For example, direct measurement of nuclei supply, that is, of ice nuclei concentrations or of ice crystal versus supercooled water concentrations taken aloft should replace present day reliance on the cloud top temperature index. These projects should be designed not only to learn more about the physical processes leading to precipitation, and their artificial modification, but also to test new improved modes of seeding and of nuclei delivery systems.

In addition, it is necessary to address the problem of what happens when the area under seeding treatment is expanded to embrace parts

of many adjacent States. At present, areas being affected by single projects cover 1 to 10,000 square miles. This includes the so-called downwind effects that have been validated by use of data from long-term randomized projects. But we already have under consideration plans for conducting large projects over the entire Wheat Belt and the entire Corn Belt. When considering such massive areas we must ask certain questions about seeding-produced alteration in water balance on not only a cyclonic scale, but on the scale of the Great Plains summer monsoon. The ultimate source of much of the moisture falling in the Great Plains and the Midwestern States in the summer is the Gulf of Mexico. How will this moisture flow be modulated by massive seeding? If no change occurs in it, then would any seeding effect be merely the result of a redistribution of water from lightly seeded, or nonseeded parts of the country to the seeded parts? In order to obtain answers, it will be necessary to set up a large aerological network (but denser than the regular synoptic network) to study the water convergence and changes therein into the Great Plains and the Midwest.

Efforts at improvements in modeling and statistical design should also be continued, but the emphasis should be on data collection in the field. At present the supply of useful models and statistical design tools has outrun the supply of good field data.

With the foregoing material as a background, I shall offer comments and suggestions upon the two bills. S. 3383 would authorize the Department of Commerce to establish national goals in weather modification in a 1-year study by the Department of Commerce. The Weather Modification Association, an international organization consisting of both private and public groups and individuals interested in weather modification, has advocated for over 10 years that a broadly based commission be formed to establish such goals, and their position was entered as testimony in the 1966 hearings. The need for establishing such goals is now stronger than ever, and I am greatly encouraged that this has been recognized by the foresighted Members of Congress who have prepared this bill.

I do have some strong reservations about this task being entrusted to a Department rather than to a new commission. A commission could have representation from not only Government agencies, private firms and the universities, but more importantly from the various user groups such as farm groups, the utility industry, and others whose support through the years has kept the field of weather modification alive and progressing.

If the task is to be entrusted to the Department of Commerce, it is most likely that NOAA will perform the work. NOAA is staffed with a depth of scientific talent that can cope with the technical complexities in general; however, there is still need for a great deal of assistance from those located in the private field, in the universities, in other Government agencies, and within user groups. There has also grown up over the last 10 years a considerable outside expertise in the economic, social, legal, and environmental aspects of weather modification. I believe that a broadly based national weather modification commission would be better able to seek out and coordinate such diverse inputs to the formulation of national goals than would the Department of Commerce. Finally, the commission would formulate a national program that might assign missions to Government agencies,

and possibly indicate a lead agency. It therefore would be difficult for a mission-oriented agency such as NOAA to objectively review other agencies work and make assignments. A plan for regulation would also be formulated.

H.R. 10039 would establish quite detailed regulations of weather modification by the Department of Commerce. It would require very extensive reporting of weather modification activities. Sufficient data should be collected that an independent analysis can be made of results at some future date and it should also be sufficient that inordinate interference between projects can be forestalled, especially where one is purely scientific and involves a heavy investment in instruments and personnel. However, due to the marginal character of seeding effects, daily evaluation of results is not possible and there is no need for daily reporting as called for in this bill. In fact, such reporting would be inaccurate because some data are not validated until sometime after the occurrence of the event being recorded.

A more basic problem with the bill is that it would establish regulation in the hands of an agency (the Department of Commerce) that already has a mission in weather modification. The avoidance of such a situation, that is, recognition of the principle of the separation of powers, has been vigorously asserted by the Weather Modification Association and by at least five of those testifying at the 1966 hearings. In addition. the complexities of overlapping Federal and State authorities contemplated in the bill would effectively block much seeding due to the time consumed in meeting the various sequential requirements. For the time being. the present reporting law-Public Law 205, 92d Congress-is believed to be adequate to meet the requirements suggested as desirable in the preceding paragraph.

Mr. BROWN. Thank you very much, Mr. Elliott.

Your comments and statement represents the first input into these hearings from one who has a long background of practical operation in this field.

Mr. Esch, do you have any questions?

Mr. ESCH. Thank you very much, Mr. Chairman.

I just want to confirm what the chairman has said as to the application phase. I am a little interested about your last comment, it is my understanding you feel you already have a system of control currently in terms of seeding programs?

Mr. ELLIOTT. That is correct. We report to the Department of Commerce and to NOAA.

Mr. ESCH. Prevailing throughout your testimony was the suggestion that if we continue to try to modify on a limited scale, we have a degree of success, but that a broader scale of modifications might pose problems.

I seem to sense that from your testimony, at least it could pose a degree of unpredictability?

Mr. ELLIOTT. Well, I have dwelled upon what is actually occurring now, and has occurred over the last 25 years, and it is on a smaller scale.

I have talked about larger scale programs, and, of course, we do have the hurricane modification project which is a larger scale project. In the future this could lead us into various problems including international problems.

Mr. ESCH. Taking your experience and background, I want to go into your projections, what kind of vehicle would be needed if we go into a much broader scale, do you think a major problem is one of liability?

Mr. ELLIOTT. Well, right now, with the present size projects, even though international, in fact, such as having a project on the Canadian border, on our side, and which would have some affect on the other side, this would be a rather limited thing, which could be handled by some kind of special conference, with one nation.

The implications of a program to control hurricanes and typhoons on the other hand would involve a number of nations, and the possibility of preventing damage by rerouting a hurricane in one area, would also involve the rerouting of water supply which might be badly needed.

That is the sort of conflict you get into.

Mr. ESCH. Thank you very much.

Thank you, Mr. Chairman.

Mr. BROWN. Mr Elliott, you gave us some figures about the costbenefit effects of modification of precipitation, and at one point in your statement, you indicated that a 10 percent increase runoff would be the equivalent of 100,000 barrels of oil.

I was not quite clear whether that was a seasonal figure, or one storm figure, or just what was the base you are talking about?

Mr. ELLIOTT. That was for one winter season; a 10 percent increase in runoff induced by cloud seeding would mean that hydropower could be used as a substitute for fossil fuel power.

Mr. BROWN. So that is one program that would last throughout the winter season?

Mr. ELLIOTT. That is correct.

Mr. BROWN. You are suggesting the need for additional data on page 8 of your statement, you said.

In my opinion we should organize a few well run field research projects where the data collected are more numerous, more reliable, and more sophisticated than has been the case heretofore.

I gather then that you feel that there are substantial knowledge gaps which require enhanced investigatory programs.

Would you care to comment on the extent of the costs, in comparison with the present programs that you feel would be adequate to deal with the main data requirements in weather modification?

Mr. ELLIOTT. My feeling is that there is a great deal of need for more scientific work to be done, especially in cumulus cloud seeding, over the Great Plains, and the Midwestern part of the country.

I feel that when the national goals are established, they should include some kind of scientific program to be carried out along these lines, and I feel that we are getting into the tens of millions of dollars in this kind of program.

Mr. BROWN. This would be beyond the scope of the private operators who would be conducting the actual operations.

They would not have any resources anywhere close to this goal to collect the data?

Mr. ELLIOTT. In the program I envisioned perhaps the operators and contractors could carry out certain field parts of it.

Universities would be involved in some of the planning, design, and evaluation, and the Government agencies would probably be involved at the point of directing.

Mr. BROWN. You have been rather emphatic with regard to your support for some modification of S. 3383.

You mentioned at several points that you feel it should include a broadly based commission rather than having a department carry out the kind of studies involved here.

You feel pretty strongly on that point?

Mr. ELLIOTT. Yes; and this has not come about suddenly.

This has been based on thinking and rethinking this problem over during the last 10 years.

Mr. BROWN. Do you have any knowledge as to why the provision regarding the commission was taken out of the bill we have now? Mr. ELLIOTT. No, sir, I have no knowledge of that.

Mr. BROWN. I can tell you there is a certain amount of general antipathy toward setting up any more commissions than we have.

Mr. ELLIOTT. I understand that. I do understand that.

Mr. BROWN. You do not think we could settle for giving direction of this, assuming this committee felt it desirable to report out some modification of the Senate bill, that we might compromise by leaving the responsibility with the department, but establishing or requiring a broadly based, rather well-defined advisory committee with the specific role in this area?

Mr. ELLIOTT. This I would think could be a possible compromise. With the reporting you would have, I do not see how it could be accomplished in 1 year.

Mr. BROWN. Yes; I tend to agree with you on that.

Would you say something closer to 2 years?

Mr. ELLIOTT. I would say from 2 to 3 years.

Mr. BROWN. Well, I find that your comments are directly to the point.

When we get to the point of marking up this bill, precisely these kinds of things will be taken up, we will be battling around this kind of thing in this committee, as we are trying to work out something that is mutually acceptable.

We are very much appreciative of your testimony this morning, and we look forward to further contacts with you on this matter.

Thank you very much...

Mr. ELLIOTT. Thank you.

Mr. BROWN. Our next witness is Prof. Lewis O. Grant, Department of Atmospheric Science, Colorado State University, Fort Collins, Colo.

Professor Grant, thank you for coming to appear before us this morning. Again, the full text of your statement will be included in the record. You may proceed in any manner which you choose.

STATEMENT OF PROF. LEWIS O. GRANT, DEPARTMENT OF ATMOSPHERIC SCIENCE, COLORADO STATE UNIVERSITY, FORT COLLINS, COLO.

Mr. GRANT. Good morning. I am Lewis O. Grant, professor of atmospheric science, Colorado State University, Ft. Collins, Colo. My areas of specialization are weather modification, cloud physics, water