ad. No estimates of diffusion coefficients are yet possible. The analysis has shown the approximate fraction of material that was transported into the southern hemisphere, but this data is not sufficient to compute any exchange coefficients. 7.4 - RECCMMENDATIONS The difficulties encountered in the analysis discussed in. this report have pointed up shortcomings that existed in some aspects of Operation IVY. The recommendations listed below are pat forward in an effort to increase the usefulness of the monitor~ dng program, and to.enhance the phenomenology of the whole problem.- a. A larger number of close-in gurmed paper stations .than was used during IVY is nacessary to locate the ' peak values of fallout and rainout a few days after ' the explosion. The use of ships should be explored. b. A series of special observationsis suggested for future tests. The experiments should be conducted in the Pacific area west of the test site to study the phenomenon of _rainout in tropical showers. c. The preliminary study of this report indicates that the: potential maximum rainout in the Hawaiian Islands is significant. A more complete analysis should investigate the probability of this occurrence and the possibility of forecasting it. d. Greater effort snould be -made to determine the height - and dimensions of the atomic clouds from megaton weapons so that the vertical extent be known. e. A sampling of the stratosphere be attempted, possibly. by balloons, to determine the present. stratospheric content of debris, as well as the content after future tests. f. A system be devised which will minimize the number of errors that appear in the final data. Perhaps a long "shake down" period previous to scheduled tests would . ’ show up thse most frequent type of error that occurs in the field and enable improvement of performance before - the tests begin. — ~