CLIMATE& GLOBAL DYNAMICS DIVISION

August 1989

CLIMATE ANXIETY As a result of the scientific, media, and public attention to possible climate change, the politi-cal wheels in Washington, D.C., are moving to-ward a government-wide research program on global change. Increased funding seems likely in the long-term, although uncertain in the short-term. Along with our university colleagues, we at NCAR have the broad spectrum of talent necessary to make signif-icant progress on understanding and predicting cli-mate change. The Climate Systems Modeling Pro-gram and the Climate Modeling Workshop of June 8 are fine examples of CGD's interest. The ques-tion is how to move from the present austere times to the promised future of more abundant resources. A new government plan, to be announced soon by the just-confirmed President's Science Advisor, in-dicates substantial increases in government agency and department budgets.

-Warren Washington

CGD MEETS SERAFIN In May, Director Robert Serafin met with CGD personnel to introduce himself and to entertain questions. The dis-cussions dealing with NCAR's research directions and its relationships with UCAR, NSF, and universities were well received and generated interest for another get-together in six months. Serafin also met individually with CGD scientists a few weeks later to learn more about their specific research.

ROUND TWO Warren Washington has completed his second round of informal gatherings with CGD staff. Meeting with one research section at a time, he is able to bring people up to date on activities division-wide, inform them of action by the Directors' Committee, and serve as a sounding board for comments and suggestions. These meetings are open to all section members, and Warren encourages their participation in the exchange.

NEWS SPEC UPDATE

The make-up of CGD's SPEC Review Panel is now offi-cial: Robert Cess (State University of New York at Stony Brook), Wallace Clark (ERL, NOAA, Boulder), Eugenia Kalnay (NMC), John Kutzbach (University of Wiscon-sin), S.G.H. Philander (GFDL), Jerry Mahlman, Chair-man (GFDL), Peter Rhines (University of Washington), and Mike Wallace (University of Washington). Gerald North (Texas A&M) and John Walsh (University of Illi-nois) are the UCAR observers, and Giorgio Tesi is the NSF observer. The Panel's charge is to " ••• review the recent accom-plishments, current activities, and future plans of the Cli-mate and Global Dynamics Division. The review should include all aspects of the work and should assess the qual-ity and productivity of the Division programs." One month before the site visit, CGD will provide Panel members with guidelines, their charge, previous SPEC Panel report and management responses, report on re-search since last review, program plans, financial data and budget estimates, and selected reprints. The review dates have not been decided but will probably fall be-tween December 1989 and March 1990.

CCM ACTIVITIES Advisory Committee The advisory committee for the community climate model met for a day and a half at NCAR in August. The charges to the committee are ( 1) to oversee the gen-eral and long-range development of the CCM, and (2) to communicate and coordinate the interests and needs of outside users. New members are Lennart Bengtsson (ECMWF), Leo Donner (University of Chicago), Eugenia Kalnay (NMC), Michael Prather (GISS), and Jay Fein (NSF). They replace John Hovermale, T. Krishnamurti, Mike Wallace, and Hassan Virji. Ferd Baer (University of Maryland), Jack Geisler (University of Utah), and Chair-man John Kutzbach (University of Wisconsin) will con-tinue to serve on the committee. Although it is difficult

Climate & Global Dynamics Division (CGD), National Center for Atmospheric Research (NCAR), P.O. Box 3000, Boulder, CO 80307. NCAR is operated by the University Corporation for Atmospheric Research under sponsorship of the National Science Foundation.

for all scientific areas of the CCM to be represented, the current membership will provide the needed expertise in chemical processes and climate modeling. CGD is still seeking another member for the committee with experi-ence in ocean coupling.

New Version of TN-335 Available

The newest version of the CCM Modular Processor, recently released, is documented by the NCAR techni-cal note, PROC02A: Enhancements to the PROCO!! Version of the CCM Modular Processor (NCAR/TN-335+1A, R. Wolski, June 1989). Because this is an addendum, the CCM Processor Users' Guide (Ver-sion PROCO!!} (NCAR/TN-290+1A, R. Wolski, Octo-ber 1987) is still required for complete documentation. The technical note is available from Eileen Boettner or Rick Wolski; it is also on the IBM 4381 (10) as file P02A DOC on the CSMLIB 191 disk.

PROC02A is now the only fully supported version of the CCM Modular Processor; PROC02 will remain archived on NCAR's Mass Storage System for some time, but it will no longer be updated with any changes. All users, therefore, should switch to PROC02A as soon as possible.

Program Libraries Expanded

Two new unresequenced CCMl program libraries, which include several bug fixes, improvements in com-putational performance, and other enhancements, in-cluding an experimental T42 version of the CCM, are documented in Modifications and Enhancements to the NCAR Community Climate Model {CCM1} (NCAR/TN-336+STR, J.J. Hack, L.M. Bath, G.S. Williamson, and B.A. Boville, June 1989). The properties of a seasonal control experiment using the new program library is also contrasted with earlier CCMl control ex-periments in this document. The new program libraries, along with the Cray Update mod files FASTCCMl MODS and UNBLOCK MODS (available from IBM 4381 user ID CSMLIB), allow the user to execute the CCM! at ap-proximately one-third the GAU cost when compared to the original CCMlPL program library. The total number of computational cycles required to execute the model has also been reduced by nearly a factor of two. Users can obtain copies in ML Room 300.

CCMJ Goes to Australia

Permission has been given to the Centre for Re-source and Environmental Studies (Australian National University-ANU) in Canberra to use NCAR's CCMl on their Facom supercomputer for the university's re-

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search projects. ANU academic consultants will install and adapt the model for, among other things, stud-ies of physical, chemical, and biological processes and their relation to plant growth, crop production, and land changes. The CCM had its origins in Australia inasmuch as the first version (CCMOA) was based on the Aus-tralian spectral model developed by Bourke, McAvaney, Puri, and Thurling. Puri (then with the Australian Nu-merical Meteorological Research Centre) and NCAR, uni-versity, and Los Alamos scientists adapted the model to the NCAR computers.

DESERVED RECOGNITION

Lifetime contributions to the atmospheric sciences by Ed Lorenz (MIT) and Phil Thompson (GDS) were recognized on July 17 at a special set of lectures and re-ception hosted by CGD, ASP, and MMM. Walt Roberts, President Emeritus of UCAR, introduced Ed and Phil to a standing-room only audience. Ed's talk dealt with a subject of much interest- "Chaos, Spontaneous Climate Variations and Detection of the Greenhouse Effect." He showed that the global warming evident in observed data records can be reproduced in a simple computer model. Phil demonstrated his knack for getting at the essence of how the global-scale motion system behaves by showing that many of the general circulation statistics can be re-produced by a relatively simple atmospheric model. The title of his talk was "Dynamics of a Low-Order General Circulation Model: Stability of Equilibrium States, At-tractors, Invariants, and Vacillation." (Photos by Charles Semmer)

BOARDS & COMMITTEES

Warren Washington will serve as NSF representative on the International Working Group on Global Change, established to advise organizations on useful initiatives and access and compatibility of data and model devel-opment. Initial membership includes Robert Sadourny (National Center for Scientific Research, Cedex), Klaus Hasselman (Max Planck Institute for Meteorology, Ham-burg), and A.E. Hughes (SER(, Swindon).

Tom Mayer represents CGD on NCAR's Database Advisory Committee. This group will explore available management software for database systems that might be useful, scientifically and administratively, to UCAR and NCAR.

CGD CLUB

At the May meeting, Guy Brasseur and Phil Rasch summarized their progress in creating a viable model for chemistry transport. They hope to conduct experiments later this year.

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AFFIRMATIVE ACTION

The UCAR Affirmative Action Plan, distributed ear-lier this summer to section heads, summarizes federal requirements and action taken by UCAR to ensure equal employment and career opportunities for all employees and applicants for employment. Copies are available in the Division Office or from Personnel.

STATUS OF CGD COMPUTING SYSTEM

As a result of the growing use of Sun workstations and concurrent decline in VAX use, AAP2, one of two VAX 11/780s running VMS, will be removed September 30 and the other VAX (AAPl) will disappear sometime in 1990. AAP2 has been given to SCD to replace the VAX 11/750 presently used to run the VMS gateway to MASnet software. It will also support the MOM network monitor and other functions that require a VMS machine.

The newest Sun 4/280, isis, is up and running. In fact, until late July, when the machine was rebooted to install a new networking package, it recorded 63 days of continuous uptime. Virtually all software on ra is now available on isis. Another disk will be added to isis in the near future.

Seven diskless nodes hang off ra. The seventh, called nimbus, occupies the office of Pat Kennedy and Gary Bates. The first Sparcstation l, to be located in Rick Wolski's office, is due in late August or early September, and the first color sparcstation will arrive in approximately three months. We expect to add more diskless nodes in the next year.

The terminal server is finally more stable, although our problems are not over yet. With the arrival of isis, use of the terminal server increased such that users were faced with queues into the terminal server for the first time in over a year. This problem had been foreseen, but the purchase of a second terminal server was delayed to allow us to cooordinate the acquisition with SCD. We expect delivery about September 1 on the new terminal server, an Annex II with 16 ports. Meanwhile, to alleviate congestion, four PACX ports have been added to our current server and two more should be added in a week or so. These last two ports are part of a set of four that allow people to reach the PACX from the terminal server and from there to reach other machines such as the IBM 4381 in SCD that are not easily available over the ethernet. Two ports will continue to serve this function along with two ports on the new terminal server.

Divisional representatives and SCD personnel have been discussing the purchase of a publication-quality laser printer. While the requirements for such a printer have now been defined, we are still waiting for news on the actual purchase.

We are expecting delivery of a Laserwriter 11 printer, the division's first postscript compatible printer. This printer will hang off isis but will be available to all the Suns for printing straight text, troff, and TeX output.

-Liz Coolbaugh

WORKSHOPS

Climate Modeling

Nearly two dozen scientists from MMM, ACD, and CGD gathered in a day-long mini-retreat on June 8 to talk about climate modeling. Presentations dealt with ocean-atmosphere GCMs, ecological models, methane budgets, ozone chemical cycle in the CCM, cumulus and hydrologic parameterizations, and interaction of societal processes and climate modeling. The retreat was orga-nized by Guy Brasseur, Bob Dickinson, Jim McWilliams, Joseph Tribbia, Dave Williamson, and John Wyngaard.

Climate Networkiiig

With funding from UNEP, ESIG organized an in-ternational workshop to assess the possibility of estab-lishing national and international networks of individuals, centers, and institutes interested in climate-related im-pacts research. Representatives from Australia, Brazil, Canada, Ethiopia, Hungary, Italy, Japan, Thailand, the United Kingdom, the United States, and Vietnam at-tended this March "networkshop" at NCAR. As a result, Hungary, Ethiopia, and Vietnam have begun to establish national networks and to produce national newsletters. Hungary received about $20,000 for the project from the Hungarian Ministry of Environment. A summary report of the workshop is available from Jan Stewart (x1618).

Quasi-Biennial OsciJlation

In June, The National Science Foundation, CEDAR, and SCOSTEP hosted an NCAR Workshop on Mecha-nisms for Tropospheric Effects of Solar Variability and the Quasi-Biennial Oscillation. Harry van Loon's contri-bution to the workshop was on "Solar Cycle and QBO-Related Changes in the Troposphere and Stratosphere."

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Harry also attended the Fourth Summer CEDAR Work-shop at NCAR in June.

PROPOSALS, PROJECTS IL AGREEMENTS

EPA/NOAA The EPA and NOAA's National Marine Fisheries

Service have jointly funded ESIG's proposal for study of possible changes in the marine environment from a global warming and the implications for society and the economy of those changes. Mickey Glantz is principal investigator. In June, experts from the 15 fisheries re-viewed the history of each fishery, discussed the specific areas needing investigation, and established specific de-tails of the project. The methodological approach for the study, referred to as "forecasting by analogy," will involve studying the 15 fisheries to determine how they and the societies dependent on them responded to changes in dis-tribution and abundance over the decades. It is hoped that the results can be used to advantage.

EPA Effective April 1989, the EPA is funding a three-

year cooperative agreement with NCAR for the study, "Methods for Analyzing Extreme Events with Applica-tion to Scenario Development for Climate Impact Assess-ment." Co-investigators Rick Katz and Barb Brown, both of ESIG, will apply the statistical theory of extreme values to develop methods for application in climate research, particularly for climate change and its impact.

HMS

In cooperation with the Hungarian Meteorological Service (HMS), ESIG has a three-year joint project (now in its second year) on identifying and coping with extreme meteorological events. Dr. Emanuel Antal, Deputy Pres-ident of the HMS; Dr. Tibor Farago, Head of the Cli-matological Department; and Dr. Csaba Nemes, Head of Climate Information Services, visited NCAR in May to consult on the project's activities. (Identifying and Coping with E,treme Meteorological Events, edited by Antal and Glantz, was published by the HMS in Novem-ber 1988.)

BATS

The Biosphere-Atmosphere Transfer Scheme, devel-oped by Bob Dickinson and others, and the Regional At-mospheric Modeling System, developed by Roger Pielke and others at Colorado State University, are the pro-posed mechanisms by which Yugoslavian scientists will test parameterizations of vegetation for meteorological

models. The proposal is still in its embryo stage, but principal investigator Dragutin Mihailovic (University of Novisad, Yugoslavia) hopes to improve existing parame-terization techniques for land-surface processes, specifi-cally drag coefficient, zero-plane displacement, roughness length, wind speed inside canopy, soil-moisture content, and aerodynamics resistance representation of sensible-and latent-heat fluxes.

Eos

NASA approval has been given to the NCAR pro-posal, "lntercomparison of Satellite-Based Global Data Sets with Global Atmosphere/Ocean Model Experiments on the Greenhouse Effect." The three-year proposal was in response to a NASA Research Accouncement under its Interdisciplinary Research Program in Earth Sciences. Principal investigator Warren Washington says that the research on the detection of the greenhouse gas signal will take advantage of the improvements in satellite data col-lection. Satellite data sets from the National Space Sci-ence Data Center and ECMWF data sets acquired from a NOAA project under the direction of Kevin Trenberth (CAS) will aid in comparing the model studies with dy-namic ocean studies of climate change. These data sets will be put into standardized format by the CCM proces-sor and, guided by the climatic signal seen in the model studies, scientists will investigate the same patterns in the observed data.

Pittsburg!, Supercomputing Center

The Pittsburgh Supercomputing Center has ap-proved 2,000 service units for the research proposal, "Cli-mate Model Experiments on the Effects of Increased Greenhouse Gases: The Role of the Oceans." Investiga-tors Warren Washington, Bob Chervin, and Jerry Meehl will study the sensitivity of long-term climate change to increased CO2 , with emphasis on the oceans in buffering and interacting with greenhouse gases. Their work will also lean toward explicitly simulating the eddy structure of global ocean currents.

SABBATICALS

Rick Katz will spend fiscal year 1990 at the Univer-sity of California, Davis, in the Department of Statistics and the Department of Land, Air, and Water Resources. In addition to promoting multidisciplinary work between the two departments, Rick will teach and conduct re-search on the development of statistical methods for an-alyzing output of climate model experiments. Rick will

also continue his research on climate extremes under an EPA cooperative agreement.

Bill Holland returned in June after six months of col-laborative leave with the Department of Oceanography, University of Hawaii.

Harry van Loon has returned from his collaborative leave in Australia (CSIRO and BMRC).

DEPUTY CHANGES

Kathy Miller has replaced Rick Katz as Deputy Head of ESIG. As reported, Rick will be on a year's sabbatical. AND FURTHER ... Steve Rhodes will be Acting Deputy while Kathy is on leave.

VIDEO SOON AVAILABLE

Tom Bettge, Warren Washington, Jerry Meehl, and Lynda VerPlank, in collaboration with Jeff Yost of the Scientific and Visualization and Media Services Group at the National Center for Supercomputing Applications, University of Illinois, have produced a videotape, "Com-puter Simulation of the Global Climatic Effects of In-creased Greenhouse Gases." A manuscript describing the video will be published in The International Journal of Supercomputer Applications. To purchase or borrow copies of the videotape, please contact NCAR's Media Relations Office at 303-497-8720.

ESIG STAFF COMPILES DIRECTORY

ESIG has compiled information on more than 160 groups, centers, institutes, and individuals in North America involved in climate-related impacts research. Each entry includes program, staff, purpose, areas of re-search, special facilities, and recent publications. The volume, Institutional Directory: Climate-Related Im,· pacts Network, can be purchased from ESIG-$5 in the United States, and $8 in Canada.

AMS OFFICE

Warren Washington is a nominee for the office of President-Elect of the American Meteorological Society. The election will take place this fall.

AWARDS

Three CGD staff members received incentive awards this spring-Dorene Howard for processing submissions and arranging two AMS conferences, Maria Krenz for overseeing the International Networkshop and preparing the Institutional Directory: Climate-Related Impacts Network, and Ann Modahl for preparing the first CGD Newsletter.

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SPORTS ILLUSTRATED

In the Yellow League of Boulder's C Division slow-pitch softball, the "Hailraisers" ended their season in July with 7 wins and 5 losses. Two CGD scientists contributed to the winning season. Bob Chervin, at various times first baseman, pitcher, and catcher, boasted a .474 batting average (considerably in excess of his weight, he says). Steve Schneider played right field (when he was in town); his weight and batting average are indeterminable.

NCAR/NOAA "Hailraisers." Back row, 1-r: Dan Breed, NCAR; Paul Kalthoff, NCAR; John Smart, NOAA; Bob Chervin, NCAR; Pat Hoffert; Tim Brown, NCAR; Irv Watson, NOAA. Front row, 1-r: John Augustine, NOAA; Lynn Johnson; Ken Heideman, NOAA; Jose Meitin, NOAA; Stan Benjamin, NCAR; Ed Szoke, NCAR. Not pictured: Steve Schneider and Stan Tyler, NCAR. (Photo by Jose Meitin)

SEMINAR COORDINATORS

Tony Slingo's tenure as seminar coordinator comes to an end 31 August. Over the last year, ably as-sisted by Eileen Boettner, he organized 47 seminars-22 by NCAR scientists, 14 by university scientists, and 11 by foreign visitors, including three by ECMWF director Lennart Bengtsson and three visitors from Moscow. All in all, Tony says that the seminars went well. The few exceptions included a speaker whose well-travelled slides continually jammed the projector, the chaotic talk that overran spectacularly, and the speaker who was late for his own seminar because the seminar organizer and others were entertaining him at lunch.

Beginning September 1, Grant Branstator will orga-nize the weekly seminars. Visitors and staff are urged to participate in this longstanding ritual. Please contact Grant at x1365 if you are eager to be among first on the schedule for the new year.

MEDIA ATTENTION

Ms. Atsuko Tsuji, a news reporter from the ASAHI Shinbun, visited NCAR in June to gather information on global climatic changes. Ms. Tsuji has authored sev-eral articles on the effects of increased carbon dioxide on global and regional climate. On this visit to NCAR, she was interested in other greenhouse gases, particu-larly methane and its effects. She met with Ralph Ci-cerone, Guy Brasseur, and Pat Zimmerman of ACD and with Mickey Glantz, Steve Schneider, and Jerry Meehl of CGD. She told Akira Kasahara, who arranged the in-terviews, that she was impressed by the balanced and active efforts at NCAR and she hopes that her article (to appear in the weekly magazine, AERA) will effectively disseminate the views of NCAR's scientists.

Footnote

With the intense interest in global warming and the greenhouse gas effect, television and documentary crews and news writers have become a familiar part of the NCAR landscape. Although many CGD staff members have graciously granted interviews and consented to film-ing, we are seeking even more volunteers to speak to the media. Please contact the Division Office if you are able to help out.

NEW STAFF

Stephanie Shearer has replaced Colleen Borchardt as administrative secretary in ICS. Stephanie, along with her cat "Scooter," came to Boulder from Danbury, Con-necticut, where she was employed by the Research and Development Division of Perkin-Elmer Corporation.

Barbara Carpenter, also a new secretary in ICS, replaces Susan Mikkelson. Barbara was employed by Hewlett-Packard for ten years and, more recently, by the Department of Commerce in Boulder.

Oceanography hired three student assistants in May-Brian Kauffman, Mark Kessel, and Tim Scheitlin. All are students at the University of Colorado and will provide programming and data-processing support for the analysis-programming of existing ocean modeling.

OCEANOGRAPHY PROJECT UPDATE

With the addition of three student assistants to the Oceanography Section, development of visualization software on the Ardent Titan computer is progressing rapidly. The first phase is the development of a geometry-based rendering package for three- and four-dimensional oceanographic data sets. This system will be used in both an interactive mode for exploratory data analysis and an automated mode for recording animations.

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ON THE LIGHTER SIDE

The following verse, courtesy of Tony Slingo, was written to celebrate Rick Wolski's fortieth birthday. Rick is an applications support programmer in charge of the (CM modular processor and a contributor to the (CM development.

RICKAWATHA By Tony Slingo

(With apologies to Henry Wadsworth Longfellow)

By the slopes of Roberts' mesa, By the shining Boulder flatirons, In the pink and concrete NCAR, Where the climate model rumbles, Rickawatha toiled and waited. He who made the mighty program, that we used to make our pictures, waited for another problem, sent to break the great processor, by another awkward user. Came it soon, a tricky one this, it could test our Rickawatha, to the limits of his knowledge. But, like morning sunshine beaming, which dispels all mists and phantoms, came the insight and the coding, yet again to find solution. Those of us who play with photons, bouncing through our cloudy model, where the F array hides lurking, monstrous coding to consume us, wait you with our breath a baiting. For we hear you are to help us, evermore to rid our program, of such dark obscure arrays. So we greet you, Rickawatha, as your new life stretches forward, for your life begins at forty, so the poet's logic has it. Long may happiness and programs, fill this new life as we laud you, and we wish you; Happy Birthday!

[Rick is recouperating at home after suffering a sec-ond heart attack in July. While he cannot receive visitors or telephone calls, your cards and notes would be most encouraging. Our best wishes to Rick for a full and rapid recovery.]

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TRAVEL NOTES

Melbourne

Grant Branstator spent a month with the General Circulation Model Group headed by William Bourke at the Australian Bureau of Meteorology Research Centre. Grant took part in BMRC's "Workshop on the Impact of SST Specification in NWP and Climate Simulation" and conferred with colleagues at Monash University.

Rotorua

Barb Brown, Rick Katz, Dennis Shea, and Kevin Trenberth presented papers at the Fourth International Meeting on Statistical Climatology in Rotorua, New Zealand, 27-31 March (see publications section of this newsletter for titles).

Amherst

Warren Washington, Jerry Meehl, Kevin Trenberth, and Rick Katz participated in the Department of En-ergy "Workshop on Greenhouse-Gas-Induced Climatic Change: A Critical Appraisal of Simulations and Obser-vations," at the University of Massachusetts, Amherst, 8-12 May. Their papers will appear in a volume of the same title edited by M. E. Schlesinger.

Fort Collins

Roi Madden gave a seminar at Colorado State Uni-versity on "The Potential for Long-Range Predictability."

Laramie

Kevin Trenberth presented a talk at the University of Wyoming on "The Origin of the 1988 North American Drought."

Livermore

Julia Slingo visited the Lawrence Livermore Na-tional Laboratory to assist in preparing and running the ECMWF model for detailed comparison with ERBE data.

Miami

Kevin Trenberth spoke at the Equatorial Pacific Ocean Climate Studies meeting on "The New Global-Ocean Wind Stress Climatology."

Princeton

Kevin Trenberth and Jerry Meehl participated in a meeting of the Intergovernmental Panel on Climate Change on "Scientific Assessment of Climatic Change."

San Francisco

Roland Madden, Dennis Shea, Jeff Kiehl, Byron Boville, and Harry van Loon attended the Seventh Con­ference on the Meteorology of the Middle Atmosphere. Roi and Byron, along with Roland Garcia (ACD), were chairmen of the conference. Jeff Kiehl was welcomed to membership on the AMS Middle Atmosphere Commit­tee while Byron retired from two years' service on the committee.

V\lasliington, D.C.

Kevin Trenberth and Warren Washington took part in a NOAA Panel Meeting on Climate and Global Change. Kevin also attended meetings of the National Academy of Sciences Climate Research Committee and the Polar Research Board.

NOT JUST ANOTHER COMPUTER

From the book ICE TIME: Climat� Science, and 1ife on Earth by Thomas Levenson, recently published by Harper & Row. Copyright (c) 1989 by Thomas Levenson. Reprinted by permission of Harper &. Row, Publishers, Inc.

WORKS IN PROGRESS

Thomas Levenson A Model Forecast

On the third floor of the National Center for Atmo­spheric Research, which stands in the foothills of the Col­orado Rockies, overlooking Boulder and the Great Plains, is a small out-of-the-way office. Apart from a narrow pas­sageway carved between door and desk, every surface in the room is covered with papers and books. Somewhere amid the clutter is a computer terminal; everywhere there are printouts; and in the middle of it all sits Bob Chervin, pushing aside a pile of documents to hang up the tele­phone.

Chervin has been talking with technicians at Cray Research, in Mendota Heights, Minnesota, creators of one of the first widely used supercomputers-the Cray lA-on which his research has depended for a decade. Chervin is a climate scientist, but he never makes obser­vations of the winds that howl across the mesa outside the NCAR building. In fact, he rarely has call to leave

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his office. The weather he studies is an imitation of the real thing, sets of equations that mimic, on the Cray lA, actual air currents, rainfall, temperature patterns, and so on. Chervin's study of climate is, in large measure, the study of climate models.

The computer that has underpinned Chervin's mock world, and made his armchair science possible, is located three floors below, in a huge fluorescent-lit room filled with a variety of electronic devices, including a bank of monitors that tell the operators which climate models are running, how long they're taking, and whether prob­lems are developing. Just in front of the monitors stand two machines that, except for one cutaway section, look faintly like the circular sofas in Victorian hotels, the over­stuffed, high-backed kind placed around pillars in lobbies. These are Cray lAs.

The computer's outer ring, just high enough to sit on, is upholstered in black vinyl; the innner ring, the back of the sofa, rises to a height of six feet and is constructed almost entirely of flat metal panels. The single section whose panels are of glass reveals only a tangle of blue and white wires and a row of copper slabs. Because there are no moving parts, the Cray operates in complete silence. Its size (about five feet in diameter) makes these machines two of the smallest in the room, yet it crunches numbers with blinding speed and in voracious quantities.

Most computers have buffers of some form, which, by slowing down an electronic signal, control the flow of information from one of its parts to the next, to reduce the chance of collision. In the lA, movement in and out of the computer's memory is regulated only by the length of the wire each signal must travel. To further decrease travel time, the wires have been made as short as possible (hence, the Cray's circular shape).

Operating at peak speed, the Cray lA can execute some two hundred million instructions a second. By com­parison, the ENIAC machine, a primitive device used, in the 1950s, to make the first computer-based weather forecasts, could manage only five thousand a second. A model that runs in one minute on the Cray lA requires forty-five minutes on an IBM mainframe and an hour and a half on a middle-sized DEC computer.

Yet, for all its speed, the Cray lA has been eclipsed-by another Cray, the X-MP, which NCAR has decided to acquire. During a recent trial, the X-MP pro­cessed data at the ungraspable peak rate of more than one billion calculations a second. The key to this leap in performance is the new machine's design, which differs radically from that of the lA. And this design is the rea­son Chervin's telephone calls to Minnesota increased for several months.

The following two pages were omitted due to copyright restrictions. The full version is available in the Archives.

Switching the model from the Cray lA to the X-M P would seem to require an almost trivial shift in perspec-tive: instruct the machine to create not one but four arrays of weather at a time. That's easily said but dif-ficult to bring about. With four processors operating si-multaneously, assumptions cannot be made about which processor will get to what part of the problem first. As Chervin worked through each of the model's subroutines, during the spring of 1986, he learned the many ways in which data within a computer can get to the wrong place at the wrong time, causing the model to "blow up."

Before Chervin managed to get his model into work-ing order, the program blew up twice. The first time, he had forgotten that the angle at which sunlight strikes the earth is different for each of the four arrays on each pass through the computer and that that difference al-ters the amount of heat each latitude receives. So he let each processor calculate the zenith angle for itself, and store it for use in the model's thermodynamic equa-tions. But because any of the four processors might call on those equations at any time, the zenith angles were selected at random, with just a one-in-four chance that they would be the right ones for a given array. To cor-rect the problem, Chervin wrote a routine that walled off the calculation of zenith angles in such a way that each processor could recall only the value calculated for the array with which it was engaged. The other glitch came when he allowed each of the processors to calculate how high clouds rose over their particular arrays and then to store that value in the same slot in the X-MP's memory-an error similar to the one that created the zenith angle mixup.

After fixing these mistakes, Chervin connived access to one of Cray's own X-MPs, getting the company to test his model at night, when demands on the machine relaxed a bit. On the day I met him, he received a call from a Cray technician, who told him that the simulation had run itself out peacefully. Ninety-seven percent of the model could be operated by all four processors at once. With a single feat of programming, Chervin cut down his twenty-year experiment from eight months to perhaps two weeks. By tailoring his mental world to the exigencies of parallel processing, he greatly extended the range of climate conditions he can study while sitting alone in a cluttered office at the end of a quiet cul-de-sac, far from the vagaries of Colorado's weather.

VISITORS

Collaborations with scientists from universities, other institutions, and government agencies are an in-tegral part of CGD's research program. We are pleased to indicate below the visitors to our division during the past six months:

Emanuel Antal, Hungarian Meteorological Service, Budapest, 22-30 May, climate impacts (ESIG)

Ferdinand Baer, University of Maryland, 14-16 Au-gust, CCM Advisory Committee meeting (Division Office)

Albert Barcilon, Florida State University, 1 June-30 July, nonlinear models of baroclinic instability (GOS)

John Bates, Goddard Laboratory for Atmospheres, 24-29 July, numerical techniques for integrating GCMs (GOS)

Aike Beckmann, Johns Hopkins University, 17 July-15 August, ocean modeling (OCEAN)

Ambassador Richard E. Benedick, U.S. negotia-tor for the Montreal Ozone Protocol, 1-31 August (ESIG)

Lennart Bengtsson, European Centre for Medium-Range Weather Forecasts, 1-31 August, review of climate modeling at NCAR (CMS)

Jon Bergengren, University of California, Santa Bar-bara, 15 July-15 September, coupling of biogeo-chemical cycles with GCMs ( ICS)

Klaus Blume!, Free University of Berlin, 13 April-4 May, climate variability (ICS)

William Bonner, National Meteorological Center, 13 June, numerical weather prediction and climate sim-ulation (CMS)

Penelope Boston, Complex Systems Research, Inc., 1 July 1989-30 June 1990, feedback of climate change on microbial production of trace greenhouse gases ( ICS)

David Bowen, University of Wales, Aberystwyth, 14 March, climate change (ICS)

Harold Brookfield, Australian National University, Canberra, 18 May, social science aspects of global change (ESIG)

11

Julio Buchmann, Federal University of Rio de Janeiro, Brazil. 1 June-30 August, climate (ICS)

Deloria Chapo, Fort Lewis Junior College, Durango. 15 June-15 August, Indian water rights and Navajo Indian Irrigation Project (ESIG)

Tsing-Chang Chen, Iowa State University. 15-31 July, 40- to SO-day tropical oscillations ((AS)

Alfred Chester, University of South Carolina, 15 June-15 August, epidemiological effects of drought (Division Office)

James Coakley, Oregon State University, 17-21 July. climate modeling (ICS)

Stewart Cohen, Canadian Climate Centre, Toronto, 2 February-17 March, impacts of climate change (ESIG)

Luc Cuyvers, Mare Nostrum Foundation, Annapolis, Maryland, 22-23 March, ocean modeling (Division Office)

Leo Donner. University of Chicago, 27-31 March; 15 June-15 September, initialization of cumulus con-vection & CCM Advisory Committee meeting (GOS)

Baldor Eliasson, Asea Brown Boveri Research Cen-ter, Baden-Dattwil, Switzerland, 1 May, greenhouse effect ( ICS)

David Erickson, Scripps Institution of Oceanogra-phy, 5-19 July, global carbon monoxide emissions (ICS)

Tibor Farag6, Hungarian Meteorological Service, Budapest, 22-30 May, climate impacts (ESIG)

Lucy Feingold, University of Delaware, 15 March 1989-14 March 1990, climate and fisheries (ESIG)

David Gates, University of Michigan, 30 May-2 June, climate modeling (ICS)

Michael Ghil. University of California, Los Angeles, 7-18 August. climate modeling and data assimila-tion (GOS)

Dale Haidvogel, Johns Hopkins University, 1 June-10 August, ocean modeling (OCEAN)

12

lien Hau, French Research Institute for Ocean Uti-lization, Brest, 30 March-20 April. balance equation numerical model (OCEAN)

Kate Hedstrom, Johns Hopkins University, 14 July-12 August, ocean modeling (OCEAN)

Ann Henderson-Sellers, MacQuarie University, North Ryde, Australia, 8-28 April, climate variability (ICS)

Jill Williams Jager, Federal Republic of Germany, 2 August-a September, climate scenarios (ICS)

Gregory Jenkins, University of Michigan, 1 June-1 August, paleoclimate modeling (Division Office)

Eugenia Kalnay. National Meteorological Center, 14-16 August, CCM Advisory Committee meeting (Division Office)

John Kutzbach, University of Wisconsin, 7-28 Au-gust, paleoclimate modeling & CCM Advisory Com-mittee meeting (Division Office)

Karin Labitzke, Free University of Berlin, 24 June-15 July, solar terrestrial relationship (CAS)

Mort LaBrecque, .Afosaic magazine, 9 March, cli-mate change (ICS)

Vitaly larichev, Shirshov Institute of Oceanology, Moscow, 27 March-30 April, asymptotic theory of adiabatic evolution of modons (OCEAN)

Ruth Lieberman, University of Washington, 14-25 May, diurnal heating cycle of CCMl (CMS)

Edward Lorenz, Massachusetts Institute of Technol-ogy, 1-30 July, chaos and greenhouse effect (Divi-sion Office)

Robert Luneberg. U.S. Embassy, Addis Ababa, Ethiopia, 10-11 July. climate-related refugee prob-lems in the Third World (ESIG)

Daniel Magraw, University of Colorado, 1 July 1989-30 June 1990, international climate policies (ESIG)

Syukuro Manabe, Geophysical Fluid Dynamics Lab-oratory, 7-9 August, climate modeling (Division Of-fice)

'

Maria Marinucci, University Dell'Aquila, Italy, 19 June-18 August, regional climate modeling (ICS)

David Mason, Beyond 2000 Television Series, 8 March, climate change (ICS)

Trevor McDougall, Commonwealth Scientific and Industrial Research Organization, Hobart, Tasma-nia, 27-30 June, mixing in the general circulation (OCEAN)

Richard Mied, Naval Research Laboratory, 14 April, physical oceanography (OCEAN)

Ralph Milliff, Harvard University, 5 April, coastal ocean modeling (OCEAN)

Steven Mullen, University of Michigan, 1 May-31 August, synoptic and dynamic meteorology, pre-dictability (GDS)

Allan Murphy, Oregon State University, 10-16 Au-gust, value of weather information (ESIG)

Terry Nathan, Iowa State University, 1-31 July, dy-namics of zonally varying flows and interactions of radiation, photochemistry, and dynamics (GDS)

Csaba Nemes, Hungarian Meteorological Service, Budapest, 22-30 May, climate impacts (ESIG)

Jerry Olson, Lenoir City, Tennessee, 28 March-12 April, 20-30 April, 26 June-15 August, climate (ICS)

Lee Panetta, Texas A&M, 30 May-3 June, large-scale dynamics (OCEAN)

Dedra Peterson, 6 June-12 August, social, eco-nomic, and epidemiological effects of drought in the United States and Ethiopia (ESIG)

Andrew Pitman, MacQuarie University, North Ryde, Australia, 8-29 April, climate variability (ICS)

Jeffrey Privette, University of Colorado, 1 June-30 August, climate modeling (ICS)

Veerabhadran Ramanathan, University of Chicago, 14-26 August, cloud-climate interactions, (CMS)

David Randall, Colorado State University, 11 April,

diurnal variations of the hydrological cycle (CMS)

Peter Raynor, Ormond College, Parkville, Australia, 1 June 1989-1 June 1990, climate modeling (ICS)

Kelvin Richards, University of Southampton, Eng-land, 6-11 July, fronts, layers, and mixing in the western equatorial Pacific (OCEAN)

Melissa Savage, University of Colorado, 12 June 1989-12 June 1990, terrestrial ecology (ICS)

Toni Schneider, National Institute for Public Health and Environmental Protection, Bilthoven, The Netherlands, 1-2 June, global climate change {Divi-sion Office}

Cornelius Schuurmans, Royal Netherlands Meteoro-logical Institute, 2 June-31 August, solar activity and atmospheric circulation (CAS)

Dan Seidov, Shirshov Institute of Oceanology, Moscow, 5-8 March, synergetics of the geophysical systems (OCEAN)

Frederick Semazzi, National Science Foundation, 14-16 August, CCM Advisory Committee meeting (Division Office)

Graeme Stephens, Colorado State University, 29 June, ice microphysics, radiation, and climate {CMS)

Ilana Stern, Massachusetts Institute of Technology, March 1989-March 1990, observational studies of the general circulation (CAS)

Graham Thomas, University of British Columbia, Vancouver, 9-28 April, climate variability and land-surface processes (ICS)

Alan Tipton, Texas A&I University, Kingsville, 22 May-2 June, statistical study of association between ENSO data sets and temperature and precipitation in southern Texas in this century {CAS)

Steven Tracton, National Meteorological Center, 22-24 May, synoptic meteorology (GDS)

Paul Valdes, University of Reading, England, 20 April, storm tracks in general circulation models (Di-vision Office)

13

James Wagner, Brown University, 6 June-31 Au-gust, operations support for VAXes and Suns (Divi-sion Office)

Wei-Chyung Wang, Atmospheric and Environmental Research, Inc., Boston, 31 May-2 June, trace gases in coupled atmosphere-ocean models (Division Of-fice)

Thomas Wigley, University of East Anglia, Nor-wich, England, 15 July-11 August, climate variabil-ity (ICS)

Tsegaye Wodajo, the National Meteorological Ser-vice Agency of Ethiopia, 11-30 July, study of early warning famine systems (ESIG)

Jorg-Olaf Wolf, Max Planck Institute for Meteorol-ogy, Hamburg, 7-19 April, oceanography (OCEAN)

David Yanuk, Johns Hopkins University, 22-27 June, ocean modeling (OCEAN)

Weijain Ye, Atmospheric and Environmental Re-search, Inc., Boston, 31 May-2 June, trace gases in coupled atmosphere-ocean models (Division Office)

PUBLICATIONS

The following publications by CGD scientists have appeared since March 1989 (* indicates non-NCAR col-laborator):

Baumhefner, D.P., 1989: The structure of systematic error and its influence on extended range prediction using the NCAR T31 climate model. Proceedings of Workshop on Systematic Errors in Models of the Atmosphere, 19-23 September 1988, Toronto, Canada, Report No. 12, WMO/TD No. 273, Geneva, Switzerland, 86-93.

Baumhefner, D.P, J.J. Tribbia, and *M.L. Blackmon, 1989: The influence of specified sea surface tem-perature and initial condition uncertainty on Monte Carlo extended range forecast ensembles. Workshop on Intercomparison of Results from Atmosphere and Ocean GCMs, WMO/TD No. 254, 3-10.

Beville, B.A., 1989: Upper boundary effects in a gen-eral circulation model. Proceedings of Workshop on Systematic Errors in Models of the Atmosphere, 19-23 September 1988, Toronto, Canada, Report No. 12, WMO/TD No. 273, Geneva, Switzerland, 272-279.

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Branstator, G. and J.D. Opsteegh, 1989: Free solutions of the barotropic vorticity equations. Journal of the Atmospheric Sciences, 46, 1799-1814.

Branstator, G.W., K.E. Trenberth, and P.A. Arkin, 1989; The April-June 1988 North American drought as a tropically forced phenomenon. Proceedings of Thirteenth Annual Climate Diagnostics Work-shop, 31 October-4 November 1988, Cambridge, Massachusetts, U .5. Department of Commerce, Washington, D.C., 220-223.

Brown, B.G. and R.W. Katz, 1989: Use of statistical methods in the search for teleconnections. Preprint Volume Fourth International Meeting on Statis-tical Climatology, 27-31 March 1989, Rotorua, New Zealand, New Zealand Meteorological Service, Wellington, New Zealand, 52-58.

*Chen, T.-C. and G.W. Branstator, 1989: A study of the atmospheric general circulation as an ini-tial value problem with the NCAR Community Cli-mate Model. Journal of Geophysical Research-Atmospheres, 94, 3427-3450.

*Christy, J.R., K.E. Trenberth, and *J.R. Anderson, 1989: Large-scale redistributions of atmospheric mass. Journal of Climate, 2, 137-148.

*Chu, P.-5. and R.W. Katz, 1989: Spectral estimation from time series models with relevance to the South-ern Oscillation. Journal of Climate, 2, 86-90.

*Chu, P.-5. and R.W. Katz, 1989: Spectrum of uni-variate time series models with application to the Southern Oscillation. Preprint Volume Fourth In-ternational Afeeting on Statistical Clima.tology, 27-31 March 1989, Rotorua, New Zealand, New Zealand Meteorological Service, Wellington, New Zealand, 72-79.

Errico, R.M. and P.J. Rasch, 1988: A comparison of various normal mode initialization schemes and the inclusion of diabatic processes. Tellus, 40A, 1-25.

Gallacher, P.C., R. Rotunno, and *K.A. Emanuel, 1989: Tropical cyclogenesis in a coupled ocean-atmosphere model. Extended Abstracts Volume, Eighteenth Conference on Hurricanes and Tropi-cal Meteorology, 16-19 May 1989, San Diego, Cal-ifornia, American Meteorological Society, 121-122.

Gent, P.R. and *M.A. Cane, 1989: A reduced grav-ity, primitive equation model of the upper equato-rial ocean. Journal of Computational Physics, 81, 444-480.

Glantz, M.H., 1989: The case scenario approach to climate related impact analysis. [dOjdrds, 93, 10-22.

*Gutzler, D.S. and R.A. Madden, 1989: Seasonal vari-ations in the spatial structure of intra seasonal trop-ical wind fluctuations. Journal of the Atmospheric Sciences, 46, 641-660.

Hack, J.J., 1989: On the promise of general-purpose-parallel computing. Parallel Computing, 10, 261-275.

Hack, J.J., L.M. Bath, G.S. Williamson, and B.A. Boville, 1989: Modifications and Enhancements to the NCAR Community Climate Model {CCM), NCAR Technical Note NCAR/TN-336+STR, Na-tional Center for Atmospheric Research, Boulder, Colorado, 97 pp.

Holland, W., 1989: A variety of experiences with various parameterizations of subgridscale dissipa-tion and diffusion. Parameterization of Small-Scale Processes, Proceedings of the 'Aha Huliko 1a Hawaiian Workshop, P. Muller and G. Holloway, editors, 17-20 January 1989, Honolulu, Hawaii.

*Iwasaki, T., 1989: A diagnostic formulation for wave-mean flow interactions and Lagrangian-mean circu-lation with a hybrid vertical coordinate of pressure and isentropes. Journal of the Meteorological So-ciety of Japan, 67, 293-312.

*Iwasaki, T., 1989: A parameterization scheme of oro-graphic gravity wave drag with two different verti-cal partitionings. Part I: Impacts on medium-range forecasts. Journal of the Meteorological Society of Japan, 67, 11-27.

*Iwasaki, T., 1989: A parameterization scheme of oro-graphic gravity wave drag with two different vertical partitionings. Part II: Zonally averaged budget anal-yses based on transformed Eulerian mean method. Journal of th.e Meteorological Society of Japan, 67, 11-27.

*Kalnay, E., *M. Kanamitsu, • J. Pfaendtner, • J. Sela, *M. Suarez, • J. Stackpole, • J. Tuccillo, *L. Um-scheid, and D. Williamson, 1989: Rules for inter-change of physical parameterizations. Bulletin of the American Meteorological Society, 70, 620-622.

Kasahara, A., *R.C. Balgovind, and *B.B. Katz, 1988: Use of satellite radiometric imagery data for im-provement in the analysis of divergent wind in the tropics. Monthly Weather Review, 116, 866-883.

Kasahara, A. and *K. Tamiya, 1989: Spin-up of Pre-cipitation Forecasts with a Global Atmospheric Model. Japan Meteorological Agency /Numerical Prediction Division Technical Report No. 29, 50 pp.

Kasahara, A. and *H.L. Tanaka, 1989: Application of vertical normal mode expansion to problems of baroclinic instability. Journal of the Atmospheric Sciences, 46, 489-510.

Katz, R.W., 1989: Statistics and decision making for extreme meteorological events. IdOjdrds, 93, 23-25.

Katz, R.W. and *T. Farago, 1989: Applications of theory of extreme values in climatology. Preprint Volume Fourth International Meeting on Statis-tical Climatology, 27-31 March 1989, Rotorua, New Zealand, New Zealand Meteorological Service, Wellington, New Zealand, 184-188.

Krenz, M.E., D.J. Stewart, and B.G. Chavez, 1989: Institutional Directory: Clim.ate-Related Impacts Network. ESIG/NCAR, Boulder, Colorado, 253 pp.

Labitzke, K. and H. van Loon, 1989: Association be-tween the 11-year solar cycle, the QBO, and the atmosphere. Part Ill: Aspects of the association. Journal of Climate, 2, 554-565.

Labitzke, K. and H. van Loon, 1989: Recent work cor-relating the 11-year solar cycle with· atmospheric el-ements grouped according to the phase of the quasi-biennial oscillation. Space Science Retiiews, 49, 239-258.

Large, W.G. and H. van Loon, 1989: Large scale, low frequency variability of FGGE surface buoy drifts and winds over the Southern Hemisphere. Journal of Physical Oceanography, 19, 216-232.

Meehl, G.A., 1989: Southern oscillation phenom-ena in a coupled ocean-atmosphere GCM. Pro-ceedings Thirteenth Annual Climate Diagnostics Workshop, 31 October-4 November 1988, Cam-bridge, Massachusetts, U.S. Department of Com-merce, Washington, D.C., 289-291.

Miller, K.A., 1989: Hydropower, water institutions and CO,-induced climate change: A Snake River anal-ogy. International Journal of Water Resources Development, 5, 71-83.

Olson, J.G. and K.E. Trenberth, 1989: Variability of surface wind stress over the oceans. Pro-ceedings Thirteenth Annual Climate Diagnostics

15

Workshop, 31 October-4 November 1988, Cam-bridge, Massachusetts, U.S. Department of Com-merce, Washington, D.C., 118-126.

*Pitcher, E.J., *M.L. Blackmon, G.T. Bates, and *S. Munoz, 1988: The effect of north Pacific sea sur-face temperature anomalies on the January climate of a general circulation model. Journal of the At-mospheric Sciences, 45, 173-188.

Rasch, P.J. and D.L. Williamson, 1989: A Compar-ison of Shape Preserving Interpolators. NCAR Technical Note NCAR/TN-339+STR, National Center for Atmospheric Research, Boulder, Col-orado, 59 pp.

Schneider, S.H. and *N.J. Rosenberg, 1989: The greenhouse effect: Its causes, possible impacts, and associated uncertainties. Greenhouse Warming: Abatement and Adaptation, N.J. Rosenberg, W.E. Easterling, Ill, P.R. Crosson, J. Darmstadter, edi-tors, Resources for the Future, Washington, D.C., 7-34.

*Semtner, A.J. and R.M. Chervin. 1989: Break-throughs in ocean and climate modeling made pos-sible by supercomputers of today and tomorrow. In Supercomputing 88: Volume II Science and Ap-plications, J.L. Martin and S.F. Lundstrom, editors, IEEE Computer Society Press, Washington, D.C., 230-239.

Shea, D.J., 1989: Some applications of statistics to solar-atmosphere relationships. Preprint 'Vol-mne Fourth International kfeeting on Statisti-cal Climatology, 27-31 March 1989, Rotorua, New Zealand, New Zealand Meteorological Service, Wellington, New Zealand, 63-66.

Slingo, A., 1989: A GCM parameterization for the shortwave radiative properties of water clouds. Journal of the Atmospheric Sciences, 46, 1419-1427.

Thompson, P.D., 1988: Period and decay rate of am-plitude vacillations in a low-order general circulation model. Journal of the Atmospheric Sciences, 45, 1279-1282.

Thompson, P.D., 1988: Stochastic-dynamic prediction of three-dimensional quasi-geostrophic flow. Jour-nal of the Atmospheric Sciences, 45, 2669-2679.

*Tollerud, E., *X.-P. Zhong, and B.G. Brown, 1989: Evaluating a composite climatology of mesoscale rainfall. Preprint Volume Fourth International

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Meeting on Statistical Climatology, 27-31 March 1989, Rotorua, New Zealand, New Zealand Mete-orological Service, Wellington, New Zealand, 216-221.

Trenberth, K.E., 1989: Temperature trends at the South Pole. Preprint Volume Fourth International Meeting on Statistical Climatology, 27-31 March 1989, Rotorua, New Zealand, New Zealand Meteo-rological Service, Wellington, New Zealand, 96-101.

Trenberth, K.E., 1989: TOGA and atmospheric pro-cesses. Understanding Climate Change, Geophysi-cal Monograph 52, IUGG Volume 7, A. Berger, R. E. Dickinson, and J. W. Kidson, editors, American Geo-physical Union, 117-126.

Trenberth, K.E. and J.W. Kidson, 1989: Effects of missing data on circulation statistics. Preprint Volume Fourth International .Af eeting on Statis-tical Climatology, 27-31 March 1989, Rotorua, New Zealand, New Zealand Meteorological Service, Wellington, New Zealand, 164-170.

Tribbia, J .J. and R.A. Madden, 1988: Projection of time-mean geopotential heights onto normal Hough modes. Meteor. Atmos. Phys., 38, Haurwitz Memorial Issue, 9-21.

Washington, W.M. and G.A. Meehl, 1989: Experi-ments on climate sensitivity due to increased CO 2 with a coupled general circulation model of the at-mosphere and ocean. Climate Dynamics, 4, 1-38.

Williamson, D.L. and P.J. Rasch, 1989: Two-dimensional semi-Lagrangian transport with shape preserving interpolation . .A[onthly }Veather Review, 117, 102-129.

Wolski, R.J., 1989: PROC02A: Enhancements to the P ROC02 Version of the CCM Modular Proces-sor. NCAR Technical Note NCAR/TN-335+1A, National Center for Atmospheric Research, Boulder, Colorado, 47 pp.