VI. SCIENTIFIC IMPLICATIONS OF AN UPPER-ATMOSPHERE SAMPLING SYSTEM Panel discussion: J. Z. Holland, moderator: E. A. Martell, L. Machta, W. J. Otting, J. F. Ahearne, E. H. Fleming Mr. Holland: I will comment on someof these points, but I suggest that, as we get into this next panel, we handle it the same way instead of going around the table. In other words we will move now from the equipment and procedure group to the more general question of scientific implications. Dr. Shreve: I'd like to suggest an additional bit of informality. When a certain speaker is up and proposes an idea or makes a point, and there are questions on this point, let’s not wait for questions until we walk all the way through the panel, since many inquiries are often lost this way. When a person is up there and makes a point with which you agree or disagree, stand and be heard. Mr. Holland: I don't know what this formula does; maybe it will blow up the place. I have tried to scribble some notes on the subject of scientific implications of upper air sampling systems during the course of the meeting. I must say, Ihave learned a great dealat this meeting. Particularly, I have much more of a feeling now that we must get information about the trace constituents and, in particular, radioactivity of the atmosphere in the range of 40 to 100 kilometers. I think things that have been said at this meeting convinced me that we in the AEC particu- larly, and a number of other people, would be derelict in not moving into these areas of studies. It is many jobs, in fact, and I think that some of the speakers before have indicated the diversity of studies that could be done along these lines. To me, two rather distinct philosophies have come out. macroscopic approach and the other a microscopic approach. One is what might be called the The macroscopic approach would deal with global distributions, many samples, statistics, maps, cross sections, inventories. It would require an inexpensive sampler, one which gives one or two variables or a small number of variables which can be measured with considerable certainty. . The microscopic approach would be perhaps the one that Dr. Magar indicated, where a sample is obtained the properties of which are precisely known: a total sample, if possible, which is analyzed extensively. grams. This is exemplified in the programs that we have had with balloons in AEC and Air Force pro- In other words, the macroscopic approach is typified by the studies that Dr. Machta and his group have done of global inventories, changes with time, and distribution with altitude and latitude of a number of nuclides. The microscopic approach is typified perhaps by Dr. Martell and his group who have gone into the aerosol chemistry and physics, size distributions and their origins, isotope ratios in some detail, and searches for peculiar properties which would tell them some thing about the history of the material. to find out the origin of the material, how it moves around, and the mixing processes. In each case the object is It seems to me that you 165