Search Results

You are looking at 1 - 10 of 329 items for :

  • Weather modification x
  • Bulletin of the American Meteorological Society x
  • All content x
Clear All
J. Eugene Haas

A description of the social context and citizen response to three weather modification projects provides an introduction to the discussion of a variety of social and economic issues related to planned weather modification. Various interest groups have markedly different perspectives on weather modification. Most persons subject to the consequences of weather modification have no opportunity to participate in the associated decision process even though they believe they have a right to do so. Factors possibly associated with conflict over weather modification are considered.

Full access
Michael Garstang, Roelof Bruintjes, Robert Serafin, Harold Orville, Bruce Boe, William Cotton, and Joseph Warburton

Research and operational approaches to weather modification expressed in the National Research Council's 2003 report on “Critical Issues in Weather Modification Research” and in the Weather Modification Association's response to that report form the basis for this discussion. There is agreement that advances in the past few decades over a broad front of understanding physical processes and in technology have not been comprehensively applied to weather modification. Such advances need to be capitalized upon in the form of a concerted and sustained national effort to carry out basic and applied research in weather modification. The need for credible scientific evidence and the pressure for action should be resolved. Differences in the perception of current knowledge, the utility of numerical models, and the specific needs of research and operations in weather modification must be addressed. The increasing demand for water and the cost to society inflicted by severe weather require that the intellectual, technical, and administrative resources of the nation be combined to resolve whether and to what degree humans can influence the weather.

Full access
Kenneth C. Young

Early progress in weather modification is attributed to a healthy interaction between theory and experiment. During the 1970s, a divergence of approaches took place. A “theoretical/experimental” approach, exemplified by the Cascade Project, focused on testing scientific hypotheses; an “observational/experimental” approach, exemplified by the Colorado River Basin Pilot Project, sought to enhance understanding of the seeding process through more detailed observations.

The theoretical/experimental school soon came to focus almost exclusively on natural cloud processes, leaving the field of weather modification nearly devoid of a theoretical component. It is suggested that this theoretical component is necessary to revitalize the field of weather modification.

Key questions are addressed. These include 1) identification of clouds that are amenable to seeding; 2) glaciogenic versus hygroscopic seeding; 3) optimizing critical seeding variables, such as seed particle concentration for glaciogenic seeding and seed particle size for hygroscopic seeding; and 4) seeding for hail suppression.

Full access
Norihiko Fukuta

Japanese weather modification activities have been surveyed. The principal works have evolved in three stages. During the early program from 1947 to 1960, the research was carried out in the major universities with sponsorship derived from the electric power companies. Many technical developments concerning the generation, detection, and behavior of artificial ice nuclei took place during this period. Experimental work was concentrated on ground seeding programs. Around the end of this period, the lack of basic knowledge in cloud seeding was realized while the practical program, although curtailed in some areas, continued operation. Tokyo Metropolitan Office of City Water Supply started developing a comprehensive but routine seeding program in order to secure the water supply in dry seasons.

The second period occurred between 1961 and 1967 when the Science and Technology Agency funded a five year project to the Japanese Artificial Rainfall Research Corporation for the purpose of obtaining more basic information on clouds and cloud seeding. This research was carried out in Kwanto and Kyushu Branches of the corporation.

In the third and most recent period starting in 1968, the research trend has been toward microphysics and dynamics of clouds with continuing effort on instrumentation development. Weather modification research of the hazard prevention type is currently emphasized.

Full access
William C. Ackermann, Stanley A. Changnon Jr., and Ray Jay Davis

The Illinois State Water Survey, a state water resources research agency, initiated efforts in 1971 to develop and secure a law for Illinois that would permit and regulate weather modification activities. Such legislation was deemed a prime requirement, not only for the proper execution of scientific experiments on weather modification in Illinois but for the general benefit of citizens of Illinois through encouragement to properly conducted activities and protection from improperly conducted weather modification operations. (It was our intention to develop a “model law” that reflected the best aspects of weather modification legislation and experience in other states, and which would serve as a model for future legislation in other states.) The efforts began in October 1971 and were completed in September 1973 with the signing of the Illinois Weather Modification Control Bill and its accompanying appropriation bill. This paper describes the type of law desired, the activities performed to secure the law, and the primary aspects of the enacted Illinois law.

Full access
Stanley A. Changnon Jr.

Weather modification activities in 1972 are reviewed to identify the major new projects, the major new findings, the major problems, and what these all mean for this exciting, often controversial science. The major new projects revealed a decided increase in interest and funding at the state and local levels, as well as new thrusts in federal programs. Non-governmental support of weather modification research and operations performed by American commercial firms exceeded $8 million, representing about 25% of the total expenditure on weather modification in the United States in 1972. Major new findings related to a variety of laboratory, instrumental, and field activities concerning planned modification of precipitation, hail, and warm fog, and also to inadvertent modification of clouds and rainfall. Several controversies regarding weather modification arose in 1972, but they all revolved more around the questions of its desirability or methodology, rather than whether it could be done. In general, 1972 was a year of 1) growing public acceptance and concern over weather modification as a technology, 2) growing local-state support of weather modification, and 3) federal reassessment of the thrust of their programs.

Full access
William R. Cotton and Roger A. Pielke

The application of three-dimensional time-dependent models to weather modification experiments along with the ways in which mesoscale simulations may be used as an aid in clarifying and formulating the physical basis of a weather modification hypothesis is discussed. It is furthermore pointed out that such models can be an aid in the design of field experiments, in the evaluation of field experiments, and in decision making during the daily operations of the experiment. Not only does the challenge of weather modification require considerable advancement in our understanding of the complex physics and dynamics of mesoscale processes, but it is also essential that we develop parameterizations of these processes in order for a mesoscale model to be of value in the post hoc analyses of weather modification experiments and as a decision aid.

Full access
Mary T. DiGiulian and Mason T. Charak

This article is a summary of all U.S. state laws relating to weather modification which were in effect at the end of 1973. Although previous studies in this area have been conducted, this is the only current summary of all state laws available in published form. The summary shows that 28 states have some form of statute on the regulation of weather modification activities ranging from simple to complex. The most prevalent provisions in the state laws are those concerning the establishment of Weather Modification Boards and Commissions, operator license requirements, penalties for not complying with state laws, permits for conducting specific weather modification operations, operators' financial responsibility for results of their modification activities, mandatory advance public notice of activities, payment of fees to obtain licenses and/or permits, operators' records and, in some instances, reports on their activities. The Environmental Modification Office of the Department of Commerce's National Oceanic and Atmospheric Administration (NOAA) will keep updated information on all state legislation related to weather modification which will be available to all interested persons.

Full access
Stanley A. Changnon

A new national effort dealing with planned and inadvertent weather modification has been recommended. The contention is that this readiness stems from finally learning important facts about how to properly design and conduct difficult experimentations; the need to study and understand ever growing inadvertent weather modification; the development of complex instrumentation and growing expertise; and more awareness of the impacts of changing the weather. Most importantly, awareness has come that progress can be made only through great attention to resolving many of the complex unknowns in the areas of cloud physics and dynamics. The potential benefits of an uncertain technology are difficult to specify, but appear sufficient to justify the research and development costs many have recommended. Either a better research program should be developed or we should essentially stop weather modification research.

Full access
David W. Reynolds, Thomas H. Vonder Haar, and Lewis O. Grant

During the past several years, many weather modification programs have been incorporating meteorological satellite data into both the operations and the analysis phase of these projects. This has occurred because of the advancement of the satellite as a mesoscale measurement platform, both temporally and spatially, and as the availability of high quality data has increased. This paper surveys the applications of meteorological satellite data to both summer and winter weather modification programs. A description of the types of observations needed by the programs is given, and an assessment of how accurately satellites can determine these necessary parameters is made.

Full access