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NOTICE: The project that is the subject of this report was approved by the Governing Board of the National Research Council, whose members are drawn from the councils of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The members of the committee responsible for the report were chosen for their special competencies and with regard for appropriate balance.
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Cover: Saarinen's Gateway Arch (1965) on the banks of the Mississippi River at the Jefferson National Expansion Memorial Park in St. Louis, Missouri, commemorates the westward expansion of the United States after Thomas Jefferson's purchase of the Louisiana Territory (1803) from Napoleon. St. Louis, a crossroads for the early French, British, and Spanish empires in North America, was a focal point for Mississippi River trade and a principal marshaling ground for the pioneer wagon trains setting out to the West on the Santa Fe and Oregon trails. The artist, Grace Roads (b. 1921), met her husband, Paul, in St. Louis (1944). They now reside in Lafayette, Colorado, part of the original Louisiana country comprising all the lands draining into the Mississippi—claimed in 1682 by René-Robert Cavelier, Sieur de La Salle, in the name of King Louis XIV. Mrs. Roads is the mother of John Roads, a member of the GEWEX panel.
Copyright 1998 by the National Academy of Sciences. All rights reserved.
Printed in the United States of America
GLOBAL ENERGY AND WATER CYCLE EXPERIMENT (GEWEX)PANEL
SOROOSH SOROOSHIAN (Chair),
University of Arizona, Tucson
BRUCE A. ALBRECHT,
University of Miami, Florida
JOHN J. BATES,
National Oceanic and Atmospheric Administration Environmental Research Laboratories, Boulder, Colorado
RICHARD E. CARBONE,
National Center for Atmospheric Research, Boulder, Colorado
SAMUEL EPSTEIN,
California Institute of Technology, Pasadena
KAREN S. HUMES,
University of Oklahoma, Norman
JAMES W. HURRELL,
National Center for Atmospheric Research, Boulder, Colorado
DEVENDRA LAL,
University of California at San Diego, Scripps Institution of Oceanography, La Jolla, California
DENNIS P. LETTENMAIER,
University of Washington, Seattle
P. CHRIS D. MILLY,
National Oceanic and Atmospheric Administration Geophysical Fluid Dynamics Laboratory, Princeton, New Jersey
PIERRE MOREL,
University of Paris, France
HAROLD D. ORVILLE,
South Dakota School of Mines and Technology, Rapid City
JOHN O. ROADS,
University of California at San Diego, Scripps Institution of Oceanography, La Jolla, California
DAVID A. ROBINSON,
Rutgers University, New Brunswick, New Jersey
JAMES A. SMITH,
Princeton University, New Jersey
ROBERT A. WELLER,
Princeton University, New Jersey
EDWARD J. ZIPSER,
Texas A&M University, College Station
Staff
H. FRANK EDEN, Senior Program Officer
PETER SCHULTZ, Program Officer
KELLY NORSINGLE, Senior Project Assistant
CLIMATE RESEARCH COMMITTEE
THOMAS R. KARL (Chair),
National Climatic Data Center, Asheville, North Carolina
ROBERT E. DICKINSON (Vice Chair),
University of Arizona, Tucson
MAURICE BLACKMON,
National Center for Atmospheric Research, Boulder, Colorado
BERT BOLIN,
Osterskar, Sweden
JEFF DOZIER,
University of California, Santa Barbara
JAMES GIRAYTYS, Consultant,
Winchester, Virginia
JAMES E. HANSON,
Goddard Institute for Space Studies, National Aeronautics and Space Administration, New York, N.Y.
PHILIP E. MERILEES,
Naval Research Laboratory, Monterey, California
ROBERTA BALSTAD MILLER,
Consortium for International Earth Science Information Network, University Center, Michigan
S. ICHTIAQUE RASOOL,
University of New Hampshire, Durham
STEVEN W. RUNNING,
University of Montana, Missoula
EDWARD S. SARACHIK,
University of Washington, Seattle
WILLIAM H. SCHLESINGER,
Duke University, Durham, North Carolina
KARL E. TAYLOR,
Lawrence Livermore National Laboratory, Livermore, California
ANNE M. THOMPSON,
National Aeronautics and Space Administration, Goddard Space Flight Center, Greenbelt, Maryland
Staff
LOWELL SMITH, Senior Program Officer
KELLY NORSINGLE, Senior Project Assistant
BOARD ON ATMOSPHERIC SCIENCES AND CLIMATE
ERIC J. BARRON (Co-chair),
Pennsylvania State University, University Park
JAMES R. MAHONEY (Co-chair),
International Technology Corporation, Washington, D.C.
SUSAN K. AVERY,
Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder
LANCE F. BOSART,
State University of New York, Albany
MARVIN A. GELLER,
State University of New York, Stony Brook
DONALD M. HUNTEN,
University of Arizona, Tucson
JOHN IMBRIE,
Brown University, Providence, Rhode Island
CHARLES E. KOLB,
Aerodyne Research, Inc., Billerica, Massachusetts
THOMAS J. LENNON,
Sonalysts, Inc., Alexandria, Virginia
MARK R. SCHOEBERL,
National Aeronautics and Space Administration, Goddard Space Flight Center, Greenbelt, Maryland
JOANNE SIMPSON,
National Aeronautics and Space Administration, Goddard Space Flight Center, Greenbelt, Maryland
NIEN DAK SZE,
Atmospheric and Environmental Research, Inc., Cambridge, Massachusetts
Staff
GREGORY SYMMES, Acting Director
H. FRANK EDEN, Senior Program Officer
DAVID H. SLADE, Senior Program Officer
LOWELL SMITH, Senior Program Officer (IPA)
ELLEN F. RICE, Program Officer/Reports Officer
LAURIE GELLER, Program Officer
PETER SCHULTZ, Program Officer
DORIS BOUADJEMI, Administrative Assistant
KELLY NORSINGLE, Senior Project Assistant
TENECIA BROWN, Project Assistant
COMMISSION ON GEOSCIENCES, ENVIRONMENT, AND RESOURCES
GEORGE M. HORNBERGER (Chair),
University of Virginia, Charlottesville
PATRICK R. ATKINS,
Aluminum Company of America, Pittsburgh, Pennsylvania
JERRY F. FRANKLIN,
University of Washington, Seattle
B. JOHN GARRICK, PLG, Inc.,
Newport Beach, California
THOMAS E. GRAEDEL,
Yale University, New Haven, Connecticut
DEBRA KNOPMAN,
Progressive Foundation, Washington, D.C.
KAI N. LEE,
Williams College, Williamstown, Massachusetts
JUDITH E. MCDOWELL,
Woods Hole Oceanographic Institution, Massachusetts
RICHARD A. MESERVE,
Covington & Burling, Washington, D.C.
HUGH C. MORRIS,
Canadian Global Change Program, Delta, British Columbia
RAYMOND A. PRICE,
Queen's University at Kingston, Ontario
H. RONALD PULLIAM,
University of Georgia, Athens
THOMAS C. SCHELLING,
University of Maryland, College Park
VICTORIA J. TSCHINKEL,
Landers and Parsons, Tallahassee, Florida
E-AN ZEN,
University of Maryland, College Park
MARY LOU ZOBACK,
United States Geological Survey, Menlo Park, California
Staff
ROBERT HAMILTON, Executive Director
GREGORY SYMMES, Assistant Executive Director
JEANETTE SPOON, Administrative Officer
SANDI FITZPATRICK, Administrative Associate
MARQUITA SMITH, Administrative Assistant/Technology Analyst
Foreword
The very nature of weather and climate demands an international perspective and a comprehensive research approach. For more than a decade, the World Climate Research Program (WCRP) has provided the context and vision for international collaboration directed toward the study of the key areas of uncertainty in our understanding of the climate system. Our efforts to understand climate variability and to predict future climate change have highlighted many aspects of the hydrologic cycle and the exchange of energy and water at the atmosphere-surface interface as areas of critically needed study. In response to this need, the international partners of the WCRP developed GEWEX (Global Energy and Water Experiment) as a major focus of international study.
The objectives of GEWEX are challenging, particularly since the nature of water and energy exchange at the atmosphere-land surface is so dependent on a wide variety of geographic factors.
No single comprehensive regional experiment can yield sufficient information to describe and characterize water and energy budgets. For this reason, the GEWEX effort to join atmospheric and hydrologic sciences is based on a research strategy that includes a number of regional studies across the world. The Continental-Scale International Project (GCIP), which has as its objective the characterization of water and energy cycling in the Mississippi Basin, is one of the major GEWEX regional study areas. GCIP focuses on understanding annual, interannual, and spatial variability, the development and evaluation of regional coupled hydrologic/atmospheric models, the development of data assimilation schemes, and the development of accessible, comprehensive data bases. Improved water resource management on seasonal to interannual time scales is a key GCIP goal.
The United States provides scientific expertise, leadership, and resources to ensure that WCRP research programs continue to be some of the most successful research programs in the earth sciences. In the case of GCIP, a major international study within the boundaries of North America, U.S. vision and commitment are essential. In achieving GCIP objectives, we improve our ability to predict future climate change and variability globally, while substantially improving our ability to assess the nature of climate and hydrologic variability within the U.S. Thus, our contributions have international significance while being of immense practical importance to our nation. We can expect GCIP to yield a number of clear, practical accomplishments in addition to improved capability to manage water and water resources. GCIP objectives specifically address the requirements needed to improve regional predictions. Regional predictions are of critical importance in assessing the impacts of climate variability and climate change. This report of the Global Energy and Water Cycle Experiment (GEWEX) Panel provides both leadership and vision by clearly reviewing our progress to date and by describing the opportunities for future progress.
Eric J. Barron
Co-chair Board on Atmospheric Sciences and Climate
Preface
A review of the Global Energy and Water Cycle Experiment (GEWEX) Continental Scale International Project (GCIP) is provided in this report. The concept of GCIP was conceived in 1990 as the United States' contribution to the overall scientific strategy of the World Climate Research Programme (WCRP) and GEWEX. As the first of the five Continental Scale Experiments (CSE), GCIP was established to quantitatively determine the hydrologic cycle and energy fluxes of the Mississippi River basin. The other continental-scale experiments will have similar objectives but for different geographic regions. The development and evaluation of coupled hydrologic-atmospheric models at resolutions appropriate to large-scale continental basins are critical to the successful achievement of the GCIP goal. The resulting coupled models will assist scientists and engineers in testing scenarios and making predictions which are more relevant at scales useful for water resources management, including drought and flood risk assessments.
Our review of the GCIP program shows that, while a great deal of progress has been made, the linking of hydrologic processes at different temporal and spatial scales remains a complex problem. It is encouraging to observe that both the atmospheric and hydrologic communities further recognize that an interdisciplinary approach and joint cooperation are required to ensure progress in developing advanced schemes which represent the hydrologic cycle in coupled models. Additional progress will also require improvement in the use of available measurement technologies for precipitation, surface radiation fluxes, wind and humidity, and soil moisture. A number of remote-sensing observation programs being planned by the international community and scheduled for launch in the first decade of the new millennium [i.e., NASA's Earth Observing Satellites
(EOS)] will greatly enhance the opportunity for progress in this area. However, realization of the full potential of these new measurements will require planning and cooperation among scientists and agencies. Participation by NASA, NOAA, NSF, and USGS is particularly important.
It is imperative that GCIP's scientific contributions not be viewed in a purely disciplinary context, because GCIP was intended primarily to be an interdisciplinary program. The GEWEX Panel realizes that there are many other critical and high-priority, single-discipline hydrologic and atmospheric problems which are not addressed under the GCIP research program. For example, improvements in cloud-resolving models and modeling of rainfall-runoff processes are but two of such critical problems. Further progress in rainfall-runoff models, for instance, is critical for accurate catchment-scale flood prediction and water resources management purposes. GCIP researchers must be ready to apply these advances when they become available. In addition, initial reports from a series of climate assessment workshops being held throughout the United States indicate that interdisciplinary studies directed at water resources are one of the primary needs in most regions of the country. Therefore, improvements of operational hydrologic and water resources management tools are critical in helping to bring global and GCIP/GEWEX-scale climate predictions down to a scale important for addressing local and regional water resources issues. The directions outlined in this report will assist agencies in implementing efforts toward meeting these critical needs.
Finally, on behalf of all panel members I wish to acknowledge the contributions of many colleagues during the course of this review: S. Benjamin, E. Berbery, R. Carbone, H. Gupta, B. Imam, Z. Janjic, R. Lawford, J. Leese, D. Lettenmaier, K. Mitchell, M. Moncrieff, E. Rasmusson, H. Ritchie, J. Schaake, D.-J. Seo, J. Shuttleworth, E. Wood, and Q. Zhao. I would also like to offer special acknowledgment on behalf of the GEWEX panel to the following staff of the National Research Council: William Sprigg, Frank Eden, Peter Schultz, and Kelly Norsingle.
Soroosh Sorooshian
Chair, GEWEX Panel
Acknowledgment of Reviewers
This report has been reviewed by individuals chosen for their diverse perspectives and technical expertise, in accordance with procedures approved by the NRC's Report Review Committee. The purpose of this independent review is to provide candid and critical comments that will assist the authors and the NRC in making the published report as sound as possible and to ensure that the report meets institutional standards for objectivity, evidence, and responsiveness to the study charge. The content of the review comments and draft manuscript remain confidential to protect the integrity of the deliberative process. We wish to thank the following individuals for their participation in the review of this report:
Wilfried Brutsaert, Cornell University, Ithaca, New York
Thomas Dunne, University of California, Santa Barbara
William L. Fisher, University of Texas, Austin
Efi Foufoula-Georgiou, University of Minnesota, Minneapolis
James Hurrell, National Center for Atmospheric Research, Boulder, Colorado
Jan Paegle, University of Utah, Salt Lake City
The report was also reviewed by one reviewer who preferred to remain anonymous. While the individuals listed above have provided many constructive comments and suggestions, responsibility for the final content of this report rests solely with the authoring committee and the NRC.
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