Robert M. White Project Stormfury: Chief, U. S. Weather Bureau and R. A. Chandler, Captain, USN status and prospects Director, Naval Weather Service

Because of the general interest within the scientific com- The investment in these experiments is a "sure" thing munity and on the part of the general public in Project in the sense that, at the very least, an increased under- Stormfury we have felt that a report at this time describ- standing of the dynamics and structure of these storms ing the present status of the project and plans for the will result, and through such understanding our ability next hurricane season would be valuable in placing in to predict their future course will improve. The benefits some meaningful perspective our agency objectives, the from even a small measure of improved prediction will accomplishments of the project and the prospects for the far outweigh the cost of undertaking such research even future. if modification of such storms ultimately proves to be Project Stormfury is an interagency cooperative effort impossible by the techniques, devices and approaches between the U. S. Navy and the Weather Bureau. It has that are being used in the Stormfury project. been in progress since 1962, at which time some early It should be clearly stated that Project Stormfury offers funding support from the National Science Foundation no immediate prospect of practical modification, nor has helped to initiate the project. Its primary objective is to it in fact been demonstrated that such a goal is attain- explore the structure and dynamics of hurricanes through able. A prerequisite for practical modification, however, a series of field experiments so that we may achieve a is a series of scientifically sound experiments carried out better understanding, improve prediction, and inquire on the full-scale atmosphere, with a postulated causal into the feasibility of modifying some aspects of these relationship based on physical laws which can be tested destructive storms. by detailed "before and after" measurements. This is To achieve this primary objective it is necessary that our intention in the Stormfury experiments, both on we be able to understand and modify the fundamental the full-scale hurricane and on its component parts, physical processes of convection on which the energy of such as the cumulus tower. Detailed, at least semi-quan- the hurricane depends. Project Stormfury therefore has titative models of the phenomenon must be the frame- as an integral part of its activities, experiments designed work upon which the experiments are based; the field to explore tropical convective processes in simple tropi- test supplies a critical proving ground for the model, a cal cumulus environments. Experimental study of tropi- benefit to science and man even if practical modification cal cumuli enables us to determine the validity of the is never achieved. underlying scientific hypotheses in a more controlled and Although Project Stormfury experiments involve the tractable environment. seeding of clouds with silver iodide, the technique of Why have we embarked upon a project of such great seeding as well as the objective of the seeding differs difficulty, whose logistics are highly complex? We have fundamentally and in essential ways from the methods embarked upon it quite simply because these storms and concepts used in most other seeding experiments. cause billions of dollars of damage and great human suf- The project uses a unique method of delivery of the fering to our nation. Even perfect prediction cannot seeding material, developed by the U. S. Naval Ord- eliminate the destruction wrought by hurricanes but can nance Test Station, Lake, Calif., involving the only reduce it. For example, during the past hurricane use of pyrotechnic generators released from aircraft. By season, during which four destructive storms hit the this method of delivery it is possible to seed a large area coast of the United States, it is estimated that over one of a supercooled cloud tower suddenly, massively, and half billion dollars in damage was caused. It is our feel- simultaneously over a large volume. The purpose of ing that our increased ability to observe and measure this seeding is not to make rain. The underlying idea these storm phenomena with the apparatus of modern is to alter the dynamics of the system by the release of technology, our increased understanding of fusion heating, when the supercooled water cloud is processes and our ability to deliver nucleating agents converted into one of ice. In the case of the individual effectively motivate in favor of exploring all reasonable cumulus, project scientists have developed a theoretical- possibilities for reducing the destructive force of such numerical model of subsequent cloud growth, which storms. predicts the cloud height-time profile and internal

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Unauthenticated | Downloaded 10/05/21 05:41 AM UTC Bulletin American Meteorological Society parameters as a function of tower radius, cloud base but they were small—and a study of natural fluctuations conditions and the environment sounding. The hurri- in hurricanes indicates it will be difficult to establish cane hypothesis relates cloud thermodynamics to synoptic- that they have resulted from man's action. Nevertheless scale storm dynamics and an hypothesized instability the results observed in Beulah cannot be dismissed. They therein. The eyewall cloud is postulated to move out- may have been due to natural causes, but what if they ward, with a reduction in the maximum wind speed, were not? What should our course be? We have decided as a consequence of warming the high cumulonimbus that in view of the enormous potential value to the towers through fusion heat additions. We must admit nation the experiment should be repeated. to serious deficiencies and over-simplification in the One seeding of a sustained circulation such as a hurri- present hypothesis. Research is underway aimed at reme- cane is probably not enough to set off a major circula- dying these deficiencies. tion instability, if there is any. Therefore a repetitive In 1963, Project Stormfury succeeded in carrying seeding experiment—five times at two-hour intervals— through a complex hurricane seeding experiment, as is planned for 1965. Monitoring with instrumented air- well as a series of tropical cumulus seeding experiments. craft over a 17-hour period is scheduled, from three hours The eyewall of a hurricane (Beulah) was seeded on two before the first seeding up to six hours following the last successive days, and a detailed "before and after" pic- one. Logistics requirements will be strained to the ut- ture of its circulation, structure, and radar cloud pat- most. Nor are there likely to be second chances in 1965. terns was obtained. In the cumulus series, six clouds Rigid operational rules preclude experimentation on were seeded and their growth measured and five others, any hurricane which could strike a populated area within apparently identical initially, were probed as controls. 36 hours. Climatology shows only two hurricanes per The whole of 1964 was devoted to analysis of results, three years visiting the Stormfury operational area in which have been published (see, for example, Malkus the Atlantic. and Simpson, 1964; Simpson and Malkus, 1964). But, if the project personnel can carry through such The logistic achievement, highlighted by carrying an operational experiment, an excellent chance is pre- through such operations, should not be minimized. sented to evaluate the existing Stormfury hurricane hy- Eleven specially equipped aircraft had to be synchronized pothesis. This is important, for if it is sound, it would under hurricane conditions or focused in time and space appear that we may be able to modify hurricanes some on a single evanescent trade . This re- day. If it is partially sound, its weaknesses can be shown quired the cooperation of countless persons, and many up and corrected; and if it is largely unsound, we have groups and subgroups in the two main agencies involved. learned something more than we knew about hurricanes, We have demonstrated that quantitative, at least par- which knowledge will be used to design new experi- tially controlled experiments can be performed on full- ments and provide a basis for better predictions of storm scale meteorological phenomena, even the mighty hurri- behavior. cane, and we have learned much about carrying out such It is intended that the experimental basis for Project large-scale cooperative efforts directed to the atmospheric Stormfury be progressively widened, for example, to in- environment. clude hurricane components other than the eyewall. A What has been accomplished is encouraging, but only rainband experiment is under consideration for this a beginning. For 1965, Project Stormfury's plans are to next year. In future years, if the project continues, it improve as many as possible of the deficiencies of the is hoped to broaden its scope still further, to design new 1963 experiments. We will attempt to design and con- models and experimental hypotheses concerning severe duct the experiments in such a way that cause and ef- storms and convective phenomena. These need not nec- fect can be clearly delineated. In the cumulus experi- essarily involve alone, but will develop as ments this goal appears not far away. Weather and physical knowledge and experimental techniques can be logistics permitting, it can probably be achieved by im- brought into conjunction. proved cloud physics instrumentation, together with The Project is now being carried out by the Navy and proper statistical controls. This year it is planned to Weather Bureau under the general supervision of its repeat the 1963 experiment with a much larger sample, Director, Dr. Joanne Simpson, of the Weather Bureau, using for each cloud chosen, a statistically sound design and Assistant Director, Captain George D. Good of the so that project scientists do not know which clouds have U. S. Navy. A small but gradually increasing permanent been seeded until the model computations are made. staff is being built by both agencies to work in collab- In the hurricane problem, causality will be much more oration. Primary Navy groups involved are the Naval difficult to establish: often hurricanes form, reverse Weather Service, which arranges for participation of the course, or go from full-blown to nothing in less than Naval activities concerned, the Bureau of Naval Weap- half a day as a consequence of the fluctuations of the ons which has developed and supplied the pyrotechnic natural forces of the environment. Thus the natural generators and coordinates on experiment design, data "noise level" may be as high as any change men can analysis and publication of results, and the Naval air- aspire to instigate artificially. In the Beulah experiment, craft squadrons that monitor flight activities, obtain the observed consequences of seeding were consistent meteorological data, and drop pyrotechnic generators. with the hypothesized chain of events in the model— In the Weather Bureau, the Research Flight Facility

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Unauthenticated | Downloaded 10/05/21 05:41 AM UTC Vol. 46, No. 6, June 1965 provides three, and it is planned later four, instrumented they were responsible for its remarkably successful exe- monitoring aircraft, and the National Hurricane Re- cution and much of the resulting data. The Project con- search Laboratory cooperates directly with aid in data tinues to profit from their experience and participation processing, and indirectly with background research on whenever they can make it available. Dr. St.-Amand unmodified storms. played a major role in the development of the pyrotech- A group of five distinguished scientists has been chosen nics (St.-Amand and Henderson, 1962) and first suggested as the new Advisory Panel to Stormfury. These consist of: their use in the program. In conclusion, hurricane experimentation presents Professor Noel LaSeur (Chair- State University enormous potential rewards for the nation. On the other man) hand such experimentation is confronted by formidable Professor C. L. Jordan Florida State University obstacles, both scientific and logistic. Like anything re- Professor Roscoe R. Braham University of Chicago lated either to or to hurricanes, Professor Edward Lorenz Massachusetts Institute public and scientific interest runs high and controversy of Technology is a normal accompaniment. We feel that every reason- Dr. Daniel F. Rex National Center for able effort to surmount the obstacles should be made, Atmospheric Research that we must avoid exaggerated promises of practical (Drs. LaSeur, Lorenz and Rex have replaced three of benefits and false claims. Above all we must strive to the original members of the Advisory Panel, Drs. Herbert design and carry out experiments which are scientifically Riehl, Joanne Malkus Simpson, and Jerome Spar.) sound. This is, we believe, a major avenue for advancing The function of the Advisory Panel is to aid in and the science of meteorology and the only way that modi- criticize experimental design, to evaluate results and fication of the atmosphere will progress from the Sunday progress, to help assign priorities in effort, and to offer supplement stage to a reality. advice on all the scientific phases of the program. The Panel's devoted effort has contributed materially to the References current progress of the project and to the fact that there Malkus, J. S., and R. H. Simpson, 1964: Modification experi- are effectively executed and evaluated experiments pres- ments on tropical cumulus clouds. Science, 145, 541-548. ently on record in the meteorological literature. St.-Amand, P., and G. W. Henderson, 1962: Project Cyclops, Particular mention should be made here of the found- an Experiment in Hurricane Modification. Report, U. S. ers of the Project, Dr. R. H. Simpson (U. S. Weather Naval Ordnance Test Station, China Lake, Calif. Bureau), Captain Max A. Eaton (U. S. Navy) and Dr. Simpson, R. H., and J. S. Malkus, 1964: Experiments in hur- Pierre St.-Amand (U. S. Naval Ordnance Test Station). ricane modification. Scientific American, 211, 27-37. Dr. Simpson evolved the current Stormfury hurricane hy- Simpson, R. H., M. R. Ahrens and R. D. Decker, 1963: A pothesis (Simpson, Ahrens and Decker, 1963) and de- Cloud Seeding Experiment in , 1961. Na- signed the hurricane eyewall experiments. Captain Eaton tional Huricane Research Project, Report No. 60, U. S. was in charge of the field operations in 1963. Jointly Weather Bureau, Washington, D. C., 30 pp.

agency responsibility aspects. The Commission hopes to have a report ready for submission to the National Science Board and the Federal Council for Science and Technology by the news and nntes late fall of 1965. Chairman of the Commission is Dr. A. R. Chamberlain, Vice President for Administration, Colorado State University; the vice chairman is Prof. John Bardeen, Department of Phys- New commission on weather modification ics, University of Illinois. Other members of the Commission In response to the need of the Federal Council for Science are: William C. Colman, Executive Director, Advisory Com- and Technology and the National Science Board for a review mission on Intergovernmental Relations, Washington, D. C.; of the state of knowledge on weather modification and control John C. Dreier, Visiting Professor of Latin American Affairs, and for recommendations concerning future policies and pro- School of Advanced International Affairs, Johns Hopkins grams, the National Science Foundation has established a Spe- University; Prof. Leonid Hurwicz, Department of Economics, cial Commission on Weather Modification. The Commission, University of Minnesota; Dr. Thomas F. Malone, Second Vice together with the National Academy of Sciences' Panel on President, Research Department, Travelers Insurance Com- Weather and Climate Modification, is engaged in making a panies; Prof. Arthur W. Murphy, Columbia University Law study and analysis of the present status and potential of School; Sumner T. Pike, Vice President, The Trident Pack- weather modification, including the scientific, social, political, ing Co., Lubec, Me.- Dr. William S. von Arx, Woods Hole and legal obstacles to attainment of progress in this field. Oceanographic Institution; Dr. Gilbert F. White, Department To accomplish this task, the Commission has created seven of Geography, University of Chicago; Dr. Karl M. Wilbur, sub-groups, each headed by one or more members of the Department of Zoology, Duke University. Jack C. Oppen- Commission, to study the physical, biological, statistical, eco- heimer was appointed executive secretary of the Commission. nomic and social, international, legal and legislative, and (More news and notes on page 327)

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