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Mid-Ocean Dynamics Experiment records

 Collection — Multiple Containers
Identifier: AC-0042

Scope and Contents of the Collection

The records of the Mid-Ocean Dynamics Experiment (MODE), 1970-1976, document the development, organization, progress, and results of a large-scale, intensive and logistically complicated oceanography program. Robert Heinmiller, a research associate at Woods Hole Oceanographic Institution (WHOI) and later coordinator of the succeeding POLYMODE project, collected the MODE records from the working files of Nick P. Fofonoff of WHOI, Executive Officer Dennis Moore, Curt Collins of the National Science Foundation, and Carl Wunsch of MIT.

Information pertaining to the development and organization of MODE can be found in files labeled "Background information" (box 1, folders 1,2). Henry Stommel's correspondence from 1969 to 1974 is particularly valuable (box 2, folder 92; box 3, folders 1,2). His correspondents included an international roster of scientists, many of whom were involved in MODE. His correspondence with Warren S. Wooster, president of the Scientific Committee on Oceanic Research (SCOR), led to the creation of a SCOR working group which examined the merits of such an experiment (also see box 2, folder 47, SCOR correspondence). More information about the development of MODE can be found in the minutes of the MODE-I Scientific Council (box 3, folders 22-29) and in the action items, agendas, and minutes of the Executive Committee (box 3, folders 30-33).

The Mid-Ocean Dynamics Experiment occurred in two phases, a sixteen-month pilot program called MODE-0 or PREMODE, and MODE-1, an intensive four-month field program. Information regarding the PREMODE program can be found in A Plan for U.S. Participation in the Mid-Ocean Dynamical Experimentation: volume I, January 1971, The Experiment 1971-1973 and [volume II], March 1971, Research Proposal Submitted to the NSF/IDOE by WHOI (box 1, folders 22, 23). A list of PREMODE projects with a brief description and assigned number can be found in box 1, folder 33 along with reviewer questions and comments from the National Science Foundation's Office for the Decade of International Ocean Exploration (NSF/IDOE), the principal funding agency.

Additional information about PREMODE (and the later MODE-1) can be found in several subseries in the administrative records, proposals (box 1, folders 43-123; box 2, folders 1,2), reports (box 2, folders 6-46), and staff records (box 2, folders 48-92; box 3 folders 1-16). The proposals and staff records have been arranged alphabetically by principal investigator. The staff files contain correspondence and papers authored by principal investigators. Included in the reports subseries are progress reports dating from 1970 to 1973 with information about equipment testing and field observations, and a draft of a MODE-0 Atlas (1973) which contains papers, data, and summaries by various investigators (box 2, folder 42). Presentations of the results of MODE-0 experiments were given by investigators at the Scientific Council meeting of January 18-19, 1973, as was a review of the overall data analysis program (box 5, cassette tapes).

More information regarding proposals funded by the NSF/IDOE and the overall administration of the MODE program can be found in the NSF/IDOE correspondence file (box 1, folder 30). The bulk of the NSF/IDOE correspondence was authored by Worth D. Nowlin, Jr. of Texas A&M University, who was acting deputy head of, and later consultant to, the NSF/IDOE.

Final strategy statements for the MODE-I field program were presented for discussion by principal investigators at the October 1972 Scientific Council meeting, and an overall plan for implementation of the field program was formulated (box 1, folder 24). The plan was revised as MODE-I: The Program and The Plan in March 1973 (box 1, folder 26). More information regarding the field program can be found in notes and correspondence of the various standing committees: Density Committee; Ship Needs and Scheduling Committee; and the Theoretical Panel (box 3, folders 34-45), as well as the MODE-1 Operations Handbook, February 1973 (box 3, folder 58). A sampling of raw data, information regarding the tracking of specific temperature isotherms from March 11-June 3, 1973 and ships' data summary sheets, is available in box 3, folders 46-49 of Series 3. Information about the ships used during the field experiment, including personnel lists, schedule revisions, and summaries of operations can be found in box 3, folders 59-66. Also, summaries of ships' progress, and work proposed and carried out, can be found in the weekly Mode Hot Line Bulletins and biweekly MODE Hot Line News (box 3, folders 69,70; box 4, folders 1-7). The latter has a cumulative index by subject and author, and a list of articles in each issue is provided in box 4, folder 8.

Much of the raw data from the experiment was incorporated into the Atlas of the Mid-Ocean Dynamics Experiment, 1977, along with each investigator's analysis of his method for data acquisition and handling. The publication documents MODE-1 and some of the succeeding post-MODE experiments, such as the tracking of some "SOFAR" floats beyond the five-month MODE-1 timetable. The MODE Atlas is arranged by project with data given on common base charts when possible, to facilitate comparison.


  • Creation: 1970 - 1976


Access note

This collection is open.

Conditions Governing Use

Access to collections in the Department of Distinctive Collections is not authorization to publish. Please see the MIT Libraries Permissions Policy for permission information. Copyright of some items in this collection may be held by respective creators, not by the donor of the collection or MIT.

Historical note

The Mid-Ocean Dynamics Experiment (MODE) was one of the first large-scale and extensively instrumented field experiments carried out by physical oceanographers. Conducted in two phases between November 1971 and July 1973, the experiment explored the role of mesoscale eddy motions in the dynamics of general oceanic circulation. Henry Stommel of MIT and Woods Hole Oceanographic Institution (WHOI) was a driving force behind the plans for the experiment. It was during British oceanographers John Swallow and James Crease's R/V Aries expedition in 1959-1960 that evidence for the existence of energetic, rotating water columns or eddies was obtained. For their experiment, free drifting floats, since known as Swallow floats, were ballasted at 2000 and 4000 meter depths in the northwestern Atlantic Ocean and tracked in an attempt to measure slow drift in deep water. Plans for a mid-ocean dynamics experiment were solidified during a summer panel meeting at WHOI on July 20-24, 1970. Thirteen academic and oceanographic institutions and an international team of oceanographers from the United States, Great Britain, Sweden, and West Germany would later agree to participate in the experiment.

MODE was as much an exercise in organization as it was a scientific experiment. Collective responsibility and authority for the experiment resided in the twenty-one-member MODE Scientific Council, formed in mid-1971. Its membership consisted of the principal investigators from each of the experimental projects and representatives from the MODE Theoretical Panel. In addition, a six-member Executive Committee, two co-chairs, Allan R. Robinson of Harvard University and Henry Stommel, and an executive officer, Dennis Moore of Nova University, monitored the overall operation of the experiment. Standing committees were created out of a need for cooperation and collective guidance among investigators. The National Science Foundation's Office for the Decade of International Ocean Exploration was the principal source of funding for the Mid-Ocean Dynamics Experiment. Other sources included the Office of Naval Research, the National Oceanographic and Atmospheric Administration, and the British National Environmental Research Council.

The intensive MODE-I field program, carried out between March and July 1973, was the culmination of a sixteen-month theoretical and observational field study known as both MODE-0 and PREMODE. The MODE-I program was a collection of twelve individual experimental and theoretical scientific projects performed simultaneously, each a substantial experiment in its own right. The field program for MODE-I was concentrated in a 600-square-kilometer test site that extended from 28 N 69 40'W, an area in the mid-ocean between Bermuda and Florida.

The duration of MODE-I was limited by the endurance of the equipment. Six ships, two aircraft, and a variety of new, sophisticated instruments, neutrally buoyant floats, "free fall" velocity profilers, and air-dropped current probes, were utilized for the experiment. The design of the experiment relied on an objective mapping scheme previously developed by meteorologists, and applied to oceanography for this experiment.

A coordinated communications network was necessary to organize the movements of the six-ship MODE fleet, personnel, and instrumentation. Undersea cables were extended from a communications center set up at the Bermuda Biological Station to land lines in the US, making phone communications between ships and participating institutions possible. Termination points were at WHOI, MIT, and Harvard, Yale, and Johns Hopkins Universities.

Information critical to the ongoing evolution of the field program, hydrostatic data, float positions, instrumentation launches and recoveries, was relayed daily to the "Hot-Line Center" and disseminated in weekly MODE Hot Line Bulletins and biweekly Mode Hot Line News publications.

MODE-I generated a massive amount of data. An important component of the experiment was the use of different instruments to measure the same phenomena from dissimilar views. In this way a greater understanding of instrument accuracy could be determined and ultimately synthesized into a description of an eddy. To provide a forum for theoretical and dynamical discussions of the eddy problem and general oceanic circulation, to disseminate synthetic analysis of MODE-1, and to develop a draft for a synoptic atlas, scientists followed MODE-I with a two-month "Summer Institute" at the University of Rhode Island in July and August of 1974. Discussions with the ten-member USSR delegation at the Summer Institute led to plans for a joint US and USSR experiment, to be called POLYMODE. The goal was to investigate the eddy field not only on the main thermocline, but also in the deep ocean and upper mixed layer.

Two films, "Storms in the Deep Sea" and "The Turbulent Ocean," both made by Centre Films, Inc. of Hollywood, California, document the Mid-Ocean Dynamics Experiment. The latter film was made for television and aired on the Public Broadcasting System in June of 1974. A third film, the "Recovery of a MODE Mooring," by Adam Gifford and Buoy Group Film, was developed for a presentation to one of the funding agencies, the Office of Naval Research.


4.5 Cubic Feet ((3 record cartons, 2 manuscript boxes, 1 large flat box, and 6 storage tubes) )

Language of Materials



The Mid-Ocean Dynamics Experiment (MODE-I), carried out between March and July of 1973, was a collection of twelve experimental and theoretical scientific projects performed simultaneously. Using different instruments to measure the same phenomena from dissimilar views, the project explored the role of mesoscale eddy motions in the dynamics of general oceanic circulation. The collection primarily consists of correspondence, notes, meeting minutes, proposals, strategy statements, and reports from the working files of various project members.

Arrangement note

The collection is organized into the following series: Series 1. Administrative Records; Series 2. Scientific Council and Standing Committee Minutes and Correspondence; Series 3. Field Experiment Data, Reports, and Administrative Material; Series 4. Publications and Related Materials.


Materials are stored off-site. Advance notice is required for use.

Related Materials

International Polymode Program records, AC 231

Missing Title

Collection on the POLYMODE Program, AC 321
Massachusetts Institute of Technology, Institute Archives and Special Collections


  • Atlas of the Mid-Ocean Dynamics Experiment: MODE-I, edited by the MODE-IAtlas Group. Cambridge: Massachusetts Institute of Technology, 1977.
  • Collins, Curtis A., and Robert H. Heinmiller. "The POLYMODE Program." Ocean Development and International Law 20: 391-408.
  • MODE-I Scientific Council. "MODE-I, the Program and the Plan: An Overview ofthe Program and Detailed Description of the Field Experiment", 1973(unpublished)
Guide to the Records of the Mid-Ocean Dynamics Experiment, 1970-1976
Deborah Shea
Description rules
Describing Archives: A Content Standard
Language of description
Script of description
Language of description note
Finding aid written in English.
The processing of this collection was funded by a grant from the United States Department of Education, Title II-C. This finding aid has been encoded by the Center for History of Physics, American Institute of Physics, as part of a collaborative project supported by a grant from the National Endowment for the Humanities, an independent federal agency.

Revision Statements

  • 2023 September 26: Revised by processing archivist Chris Tanguay to correct the location of the film "Storms in the Deep Sea" and materials in tubes. Researcher provided context was also added to the description of some materials in Series 3.

Repository Details

Part of the Massachusetts Institute of Technology. Libraries. Department of Distinctive Collections Repository

Massachusetts Institute of Technology Libraries
Building 14N-118
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