conference summary Hugh W. Church
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conference summary Hugh W. Church Sandia Corporation Symposium on the theory and measurement of atmospheric Albuquerque, N. Mex. turbulence and diffusion in the planetary boundary layer Sandia Laboratory of Albuquerque and the U.S. Army Atmospheric Sciences Office of White Sands Missile Range, N. Mex., cosponsored a symposium on The Theory and Measurement of Atmospheric Turbulence and Diffusion in the Planetary Boundary Layer. The three days of sessions were held 5-7 December 1967 at the White-Winrock Motor Hotel in Albuquerque. Co- chairmen of the meeting were James D. Shreve, Jr., of Sandia and Frank V. Hansen of White Sands. The 116 registrants represented a total of 22 states and 4 foreign countries. Eight industrial exhibits plus frequent coffee and rolls formed a focus for frequent informal discussions among the attendees. Complete preprints were available for about a third of the 22 formal presentations and a complete proceedings will be published by Sandia Corporation in early 1968. The sponsors' intent was to provide an opportunity for the exchange of information among active partici- pants in the disciplines of atmospheric turbulence, dif- fusion, and meteorological instrumentation and to deter- mine the present level of knowledge of dispersal of contaminants in the planetary boundary layer. These objectives were to be promoted from the vantage points of both theory and actual applications. It is difficult to summarize a symposium such as this in a few paragraphs, but perhaps a breakdown of the topics discussed by the presenting authors would aid such a summary. Many of the papers, of course, overlap subject areas making clear-cut demarcation an arbitrary task. Talks on latest theory of turbulent diffusion with varying degrees of summarization and application were given by 8 speakers: F. Pasquill, H. A. Panofsky, W. C. Swinbank, H. H. Lettau, G. T. Csanady, E. W. Titt, R. E. Luna and R. E. Meyers. Eight other speakers considered results of field experiments and their relation to theory and prediction problems: A. K. Blackadar, H. E. Cramer, P. Frenzen, C. E. Elderkin, R. N. Swan- son, J. S. Cornett, M. Armendariz, and J. W. Reed. Two papers dealt with furthering knowledge of atmo- spheric boundary layer flow phenomena from laboratory scale experiments: R. N. Meroney, and J. D. Horn. The final category included 4 papers giving descriptions of tower or site instrumentation bearing directly on boundary layer problems: R. I. Glass,* H. W. Church, W. M. Culkowski, and R. W. Titus. The banquet address was given by E. L. Deacon of Australia who touched on some historical aspects of tur- * Mr. Glass lost his life one week after the symposium in an automobile accident on 14 December 1967. bulence research. H. A. Panofsky, in addition to his first- session paper, gave a talk on the recent IUGG quadren- nial meetings at a meeting of the Albuquerque Chapter of the AMS. A panel discussion, moderated by J. A. Businger, covered the topic: Instrumentation and Tech- niques for Obtaining Representative Meteorological Measurements for Turbulent Diffusion. The panelists were: G. C. Gill, P. B. MacCready, R. R. Pintar, and H. C. Eberline. A luncheon was scheduled on the last day at which F. Pasquill of England gave a summary discussion of the symposium. Results of the symposium probably are indicated best by noting some of Dr. Pasquill's summary remarks at the luncheon in which he proceeded to address the list of 6 questions put forth by H. Rachele, keynote speaker, before the first session. Two of the questions were considered together: "What theories should be used for the problem at hand—what physical and/or statistical models and equations?" and "How universal are experimental results?" By way of an answer Dr. Pas- quill posed the question: "Can the diffusion processes be described by what might be called a simple diffusion model—one which uses the quantity called K?" To de- cide this, one needs to determine whether the air motion which is doing the diffusing of material is on a scale smaller than the domain over which the diffusion is to occur. Unfortunately, frequently such is not the case, as for the meandering continuously emitting plume. How- ever, the criterion is probably valid for the case of vertical transfer for then the problem becomes one of specifying the appropriate K. It was seen to vary for heat content of air, for water vapor content, and for its momentum from several of the session papers. There are also statistical and similarity treatments to diffu- sion problems which supply interesting feedback to the K treatment. One such K specification is the product of the intensity of the vertical component of turbulence and a scale represented by the peak of the logarithmic spectrum of vertical velocity variance. However, the coefficient seems to vary by a factor of three depending on whether the constant stress layer is considered or whether a layer of homogeneous turbulence is con- sidered outside of the constant stress layer. The next question was: "Has our knowledge of the atmosphere kept pace with theory? For instance, what is the importance of, and knowledge of space-time vari- ability of meteorological parameters which affect diffu- sion and what are the diffusive characteristics within 266 Vol. 49, No. 3, March 1968 Unauthenticated | Downloaded 11/24/21 07:50 AM UTC
Transcript of conference summary Hugh W. Church
conference summary Hugh W. Church Sandia Corporation
Symposium on the theory and measurement of atmospheric Albuquerque, N. Mex. turbulence and diffusion in the planetary boundary layer
Sandia Laboratory of Albuquerque and the U.S. Army Atmospheric Sciences Office of White Sands Missile Range, N. Mex., cosponsored a symposium on T h e Theory and Measurement of Atmospheric Turbulence and Diffusion in the Planetary Boundary Layer. T h e three days of sessions were held 5-7 December 1967 at the White-Winrock Motor Hotel in Albuquerque. Co-chairmen of the meeting were James D. Shreve, Jr., of Sandia and Frank V. Hansen of White Sands.
The 116 registrants represented a total of 22 states and 4 foreign countries. Eight industrial exhibits plus frequent coffee and rolls formed a focus for frequent informal discussions among the attendees. Complete preprints were available for about a third of the 22 formal presentations and a complete proceedings will be published by Sandia Corporation in early 1968.
T h e sponsors' intent was to provide an opportunity for the exchange of information among active partici-pants in the disciplines of atmospheric turbulence, dif-fusion, and meteorological instrumentation and to deter-mine the present level of knowledge of dispersal of contaminants in the planetary boundary layer. These objectives were to be promoted from the vantage points of both theory and actual applications.
It is difficult to summarize a symposium such as this in a few paragraphs, but perhaps a breakdown of the topics discussed by the presenting authors would aid such a summary. Many of the papers, of course, overlap subject areas making clear-cut demarcation an arbitrary task. Talks on latest theory of turbulent diffusion with varying degrees of summarization and application were given by 8 speakers: F. Pasquill, H. A. Panofsky, W. C. Swinbank, H. H. Lettau, G. T . Csanady, E. W. Tit t , R. E. Luna and R. E. Meyers. Eight other speakers considered results of field experiments and their relation to theory and prediction problems: A. K. Blackadar, H. E. Cramer, P. Frenzen, C. E. Elderkin, R. N. Swan-son, J. S. Cornett, M. Armendariz, and J. W. Reed. Two papers dealt with furthering knowledge of atmo-spheric boundary layer flow phenomena from laboratory scale experiments: R. N. Meroney, and J. D. Horn. T h e final category included 4 papers giving descriptions of tower or site instrumentation bearing directly on boundary layer problems: R. I. Glass,* H. W. Church, W. M. Culkowski, and R. W. Titus.
T h e banquet address was given by E. L. Deacon of Australia who touched on some historical aspects of tur-
* Mr. Glass lost his life one week after the symposium in an automobile accident on 14 December 1967.
bulence research. H. A. Panofsky, in addition to his first-session paper, gave a talk on the recent IUGG quadren-nial meetings at a meeting of the Albuquerque Chapter of the AMS. A panel discussion, moderated by J. A. Businger, covered the topic: Instrumentation and Tech-niques for Obtaining Representative Meteorological Measurements for Turbulen t Diffusion. T h e panelists were: G. C. Gill, P. B. MacCready, R. R. Pintar, and H. C. Eberline. A luncheon was scheduled on the last day at which F. Pasquill of England gave a summary discussion of the symposium.
Results of the symposium probably are indicated best by noting some of Dr. Pasquill's summary remarks at the luncheon in which he proceeded to address the list of 6 questions put forth by H. Rachele, keynote speaker, before the first session. Two of the questions were considered together: "What theories should be used for the problem at hand—what physical and/or statistical models and equations?" and "How universal are experimental results?" By way of an answer Dr. Pas-quill posed the question: "Can the diffusion processes be described by what might be called a simple diffusion model—one which uses the quantity called K?" T o de-cide this, one needs to determine whether the air motion which is doing the diffusing of material is on a scale smaller than the domain over which the diffusion is to occur. Unfortunately, frequently such is not the case, as for the meandering continuously emitting plume. How-ever, the criterion is probably valid for the case of vertical transfer for then the problem becomes one of specifying the appropriate K. It was seen to vary for heat content of air, for water vapor content, and for its momentum from several of the session papers. There are also statistical and similarity treatments to diffu-sion problems which supply interesting feedback to the K treatment. One such K specification is the product of the intensity of the vertical component of turbulence and a scale represented by the peak of the logarithmic spectrum of vertical velocity variance. However, the coefficient seems to vary by a factor of three depending on whether the constant stress layer is considered or whether a layer of homogeneous turbulence is con-sidered outside of the constant stress layer.
The next question was: "Has our knowledge of the atmosphere kept pace with theory? For instance, what is the importance of, and knowledge of space-time vari-ability of meteorological parameters which affect diffu-sion and what are the diffusive characteristics within
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Bulletin American Meteorological Society
and above a canopy?" T h e answer is clearly "no" where a considerable depth of the planetary boundary layer is involved. Theory is probably adequate for layer depths of up to about 100 meters, but within a few thou-sand meters it is inadequate. A start to the work of obtaining a more intelligent description of this deep layer has been made with the use of very high towers and captive balloons, but much more effort is required with both.
Another question was: "Are the present sensors, re-cording systems, and processing techniques adequate for turbulence and diffusion studies, particularly on the micro- and meso-scales?" Certainly great ingenuity has gone into the design and use of measuring systems. The prevalent problem of detailed measurements over-running some of their practical usefulness may be avoided if the sort of critical attitudes evident in the comments and questions at this symposium are applied.
The next question considered by Dr. Pasquill was: "What is the present state of knowledge of diffusion over non-homogeneous terrain or during non-stationary con-ditions?" There have not been exhaustive discussions on this here because of limited time, but there were some interesting attempts to generalize and rationalize about the effect of roughness and, in particular, of buildings. This trend is encouraging to the production of quanti-tative and useful results along these lines.
T h e last question dealt with the density of instru-mentation required for diffusion studies. This, of course, is quite difficult to generalize, but must be considered on each occasion and must be sorted out with the ef-fective scale envisaged for any experiment or problem.
Support for graduate programs at SUNYA The Department of Earth and Atmospheric Sciences of the State University of New York at Albany (SUNYA) announces the availability of graduate assistantships and fellowships to qualified students. Stipends range from $2500 for the aca-demic year to $3800 for the calendar year. Tuition costs are waived.
The atmospheric science faculty consists of 14 members plus a technical staff. Research programs include atmospheric electricity, cloud physics, atmospheric dynamics, airglow and aurora, micrometeorology, and physical limnology. Well-equipped research laboratories are available in the new Earth Science Building, which opened in September 1967. Through
In conclusion Dr. Pasquill noted that it was probably no surprise to say that there is still a great deal of hard work to be done on a large number of programs needing elucidation.
T h e preceding provides only a review of the high points, however it should indicate to some degree the value of the meeting. The participation of many of the foremost authorities, with high quality papers and active discussions among attendees combined to make the symposium a success.
Discussing some aspects of the Symposium program are (1 to r) Drs. W. C. Swinbank, J. D. Shreve, Jr., F. A. Pasquill and H. A. Panofsky.
the cooperation of the Atmospheric Sciences Research Center (ASRC, SUNYA) fully equipped field laboratories are supported on Whiteface Mountain, N.Y., at Lake George, N.Y., and at Schenectady Airport, N.Y. (Laboratory for Cloud Physics).
Applicants need not have had previous course work in atmospheric science. Candidates with a strong background in science, mathematics, and engineering are encouraged to apply.
Applicants should write to: Chairman, Department of Earth and Atmospheric Sciences, State University of New York, Albany, N.Y. 12203. (More announcements on page 316)
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C C M C H D C * o r r a c^'a t'o n measurements, Box 2 3 0 - M J C l N j U I W . . . . solar and/or terrestrial 2 3 0 N A S S A U STREET PR INCETON, N . J . 0 8 5 4 0
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