Biographical Memoirs Volume 66 (1995) / Chapter Skim
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Jule Gregory Charney
Jule Gregory Charney
Pages 80-113
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From page 81... ...
Much of the change in meteorology from an art to a science is due to his scientific vision and his thorough commitment to people and programs in this field. In 1946 he married Elinor Kesting Frye, a student of logic and semantics with H
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One of his amusing recollections in later years was of having played games with the young prodigy Yehudi Menuhin on top of Yehudi's apartment building, and in using this fact many years later to establish an element of mutual recognition with the world famous violinist. His last three high school years were spent at Hollywood High School after the family moved from Boyle Heights in east-central Los Angeles.
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From page 83... ...
Holmboe from the newly formed meteorology group in the Physics Department to talk. Having introduced Jule to the iclea of meteorology as a field with some scientific possibility, Holmboe invited Jule in the spring of 1941 to be his assistant and to participate in the meteorology training program taking shape at UCI~A and other universities under sponsorship of the army and navy.
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Rossby used a simple mode! of a purely horizontally moving homogeneous atmosphere to arrive at a quantitative formula for the speech at which these systems (now called Rossby waves)
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van Neumann he was to show how the newly developed electronic computer could be used to make forecasts by numerical integration of the hydrodynamical equations of motion, beginning with the observed picture of those motions that had then become available from a greatly expanded network of daily radiosonde stations. The basic premise of this physically based procedure was not new, having been stated by V
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From page 86... ...
Kaplan (where he recalled being just one lecture ahead of the classy and assisted in preparing notes for Holmboe's lectures on basic principles of fluid dynamics of the atmosphere. Jule's university social life was happy.
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From page 87... ...
Furthermore, even a resting atmosphere can sustain propagation of sound waves and of gravity waves, as well as the more recently recognized Rossby waves. To arrive at a tractable mathematical problem, Jule found it necessary to make a set of consistent approximations in his derivation of the final governing differential equation.
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From page 88... ...
NUMERICAL WEATHER PREDICTION AND PRINCETON In the months before his thesis defense in the spring of 1946 Charney explored several avenues for a postgraduate fellowship, having in mind that he was, in spite of his thesis, a newcomer to fluid mechanics. He was awarded a National Research Council fellowship, tenable in Europe, and he made plans to visit H
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From page 89... ...
The subject was the application of electronic computers to weather forecasting. Von Neumann had recently recognized weather prediction as a prime candidate for application of electronic computers, in particular the new computer that was being built to his specification at the Institute.
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~ wind belt containing the same physical mechanism as that in Jule's thesis, but in a simpler form. They became good friends and Eady later spent a part of a year with {ule at Princeton.
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From page 91... ...
Thompson in November 1947, was justified by a careful scale analysis of the terms in each of the hydrodynamic equations for momentum, for mass, and for entropy. This scale analysis was similar in principle to the consistent approximation steps Jule had been lecl to in arriving at the governing differential equation for his thesis.
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From page 92... ...
, but Jute had in effect proved with his scale analysis that this system was a consistent approximation for large-scale atmospheric motions. In early 1948 van Neumann invited rule to head the meteorology group in his Electronic Computer Project, whose financial support came from the Office of Naval Research.
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From page 93... ...
This was answered by appeal to the three-dimensional group velocity of Rossby waves in a uniform current from the west. But the full three-dimensional geostrophic system, straightforward as it was, was still too demanding for von Neumann's computer.
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From page 94... ...
They linearized the barotropic equation to treat perturbations on a uniform flow in a narrow westeast channel and expanded Rossby's frequency formula into a Green's function that would give a twenty-four-hour forecast of the initial flow pattern by simple weighted longitudinal integration of the initial distribution of the isobaric height at the barotropic level. Tests gave very promising results, indicative of success to come when the new computer could be applied to the full nonlinear vorticity equation.
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From page 95... ...
Reichelderfer, at van Neumann's request, wrote in September 1949 to General Hughes, Chief of Army Ordnance, for permission to use the ENIAC computer at Aberdeen Proving Grounds. Von Neumann had developed a technique for using Fourier sums with cyclic input and output of punched cards that allowed the nonlinear vorticity equation to be integrated on the ENIAC, whose internal storage was small.
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From page 96... ...
This development was an example of the instability that Jule had described in his thesis and was convincing vindication of his graduate work seven years earlier. This was the peak of Juleps interest in personally pursuing numerical weather prediction, although he was to make several theoretical contributions in later years.
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From page 97... ...
The new prediction method spread rapidly, with assistance from the Princeton group. In August ~ 952 von Neumann organized a meeting to consider operational use of the new method by the weather services of the United States, and by February 1954 the computer had been selected for what was known as the Joint Numerical Weather Prediction Unit, representing the Weather Bureau, Air Force, and Navy.
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Von Neumann hac3 become an atomic energy commissioner with heavy duties in Washington and it was clear that the Electronic Computer Project, with its applied flavor, was not to be a permanent feature of the Institute; pure mathematics was the preferred science there. Oppenheimer was unable to promise a permanent membership to yule, although both men respected each other and the mutual benefit that the Institute and yule had on one another.
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From page 99... ...
Malkus in the Mathematics Department he at once organized an informal seminar on geophysical fluid dynamics. This seminar was held fortnightly on late Friday afternoons and gradually involved people from the meteorology, oceanography, geophysics, and applied mathematics groups at MIT, Harvard, and Woods Hole, with frequent participation from Yale, Brown, and the University of Rhode Island.
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From page 100... ...
Jule played no role in the organizational meetings that followed, but he was very active in assisting Malone in the more technical meetings that described the activity the new center would concluct above and beyond that done at univarsities. These initial steps, when supplementecl by the organizational drive of the leading department chairmen, led to incorporation of the University Corporation for Atmospheric Research in March 1959 and the formation soon
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From page 101... ...
then the International Council of Scientific Unions to develop plans to this end in operational practice and research. {ule recalled that soon after, at a meeting of the American Meteorological Society dealing with international coOperation in meteorology, he was struck with the fact that,
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From page 102... ...
In 1966 he became leader of the National Academy of Sciences' Committee on the Global Atmospheric Research Program GARP, as it came to be called and held this demanding position until 1971. He was active in several working groups, even to the extent of being scientific ctirector for one month of the preliminary GARP tropical observing experiment in Barbados.
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The drive behind this workshop was to help reduce flooding in Venice; the successful operation of a massive floodgate project would need accurate prediction of water level in the upper Adriatic. The fluid dynamical mode]
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antiwar candidates in the primaries and the November election. TWENTY-FIVE YEARS OF RESEARCH AND TEACHING At MIT Jule continued to be a prolific creator of new icleas on the dynamics of atmospheric motion.
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The first of these gave an immediate qualitative explanation of the near absence of Rossby waves in the trade winds of low latitudes and in the westward flow that characterizes the summer stratosphere. Both results have since been extended and amplifiecl in many ways by theoretical and observational scientists, although rulers attention was quickly attracted again to another aspect of quasi-geostrophic motion.
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From page 106... ...
who first pointed out that the simple vertical stability considerations traditionally applied to explain individual cumulus clouds did not apply as a whole to the much larger hurricane cloud system. rule and Eliassen then directed their approach to recognize that the storm was in a state of near dynamic balance and that it must be the frictionally induced indraft of air near the ocean surface that supplied water vapor and latent heat to the vortex.
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From page 107... ...
This is the type of motion created in a wind tunnel and in more recent years has been found uncler windy conditions in the layer of air near the ground. Several theoreticians had in the meantime considered two-dimensional turbulence as a pure mathematical abstraction (there seemed to be no way to create it experimentally!
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From page 108... ...
always included support for about five graduates in addition to a postdoctoral visitor. He shared supervision of some students with other faculty, but Jule was the sole supervisor Of most of them, especially in later years when his GARP duties diminished.
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Jule will certainly be remembered for his research in atmospheric and oceanographic science and for his insight and initiative in the global atmospheric research program. But future chroniclers may well rank his students as an equally great contribution.
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N CAR/ TN-298+Proc (1987~. The American Meteorological Society published a memorial volume titled The Atmosphere- A Challenge and subtitled "The Science of Jule Gregory Charney," edited by R
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von Neumann. Numerical integration of the barotropic vorticity equation.
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On the trapping of unstable planetary waves in the atmosphere.
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From page 113... ...
Oceanic analogues of large-scale atmospheric motions. In Evolution of Physical Oceanography.
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