Solar Influences
On
Global Change
National Academy Press
Washington, D.C. 1994
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 ad hoc group responsible
for the report were chosen for their special competences and with
regard for appropriate balance.
This report has been reviewed by a group other than the authors
according to procedures approved by a Report Review Committee
consisting of members of the National Academy of Sciences, the
National Academy of Engineering, and the Institute of Medicine.
This work was sponsored by the National Science Foundation,
National Aeronautics and Space Administration, National Oceanic and
Atmospheric Administration, United States Geological Survey, United
States Department of Agriculture, Office of Naval Research, and
Department of Energy under Contract No. OCE 9313563.
Library of Congress Catalog Card No. 94-67788
International Standard Book Number 0-309-05148-7
Additional copies of this report are available from:
National Academy Press
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Cover artist, Marilyn Marshall Kirkman finds her artistic
inspiration in the Rocky Mountain West. Born in Wyoming and
now living in Colorado, she is surrounded by a world that
demands expression. Vivid color and strong values, eliciting
light, convey her message.
Marilyn Kirkman attended Mills College and is a graduate of the
University of Wyoming. Having been a teacher and parent, she
is now a freelance artist. Largely self-taught, she
specializes in watercolor painting. Her work is represented
by the Arati Artists Gallery, Colorado Springs, CO.
Copyright 1994 by the National Academy of Sciences. All rights
reserved.
Printed in the United States of America
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BOARD ON GLOBAL CHANGE
EDWARD A. FRIEMAN, Scripps Institution of Oceanography, Chairman
ERIC J. BARRON, Pennsylvania State University
ROBERT COSTANZA, Maryland Institute for Ecological Economics
JEFF DOZIER, University of California
PETER EAGLESON, Massachusetts Institute of Technology
PRISCILLA C. GREW, Minnesota Geological Survey
RICHARD E. HALLGREN, American Meteorological Society
ESTELLA LEOPOLD, University of Washington
PAMELA A. MATSON, NASA-Ames Research Center
VEERABHADRAN RAMANATHAN, University of California, San Diego
VERNON W. RUTTAN, University of Minnesota
ROBERT H. SOCOLOW, Princeton University
KARL K. TUREKIAN, Yale University
GUNTER WELLER, University of Alaska
Ex-Officio Members
(U.S. Members, ICSU Scientific Committee for the International Geosphere-Biosphere Program (IGBP))
JAMES J. McCARTHY, Harvard University
JERRY M. MELILLO, The Ecosystem Center
S. ICHTIAQUE RASOOL, University of Paris VI
(U.S. Members, Joint Scientific Committee for the World Climate Research Program (WCRP))
MARGARET S. LEINEN, University of Rhode Island
JERRY D. MAHLMAN, National Oceanic and Atmospheric Administration
(U.S. Member, International Steering Committee for the Human Dimensions of Global Change Program)
HAROLD K. JACOBSON, University of Michigan
Staff
JOHN S. PERRY, Staff Director
CLAUDETTE BAYLOR-FLEMING, Administrative Assistant
DONALD H. HUNT, Consultant
Page iv
COMMISSION ON GEOSCIENCES,
ENVIRONMENT, AND RESOURCES
M. GORDON WOLMAN, The Johns Hopkins University, Baltimore, MD, Chairman
PATRICK R. ATKINS, Aluminum Company of America, Pittsburgh, PA
EDITH BROWN WEISS, Georgetown University Law Center, Washington, DC
PETER S. EAGLESON, Massachusetts Institute of Technology, Cambridge, MA
EDWARD A. FRIEMAN, Scripps Institution of Oceanography, La Jolla, CA
W. BARCLAY KAMB, California Institute of Technology, Pasadena, CA
JACK E. OLIVER, Cornell University, Ithaca, NY
FRANK L. PARKER, Vanderbilt/Clemson University, Nashville, TN
RAYMOND A. PRICE, Queen's University at Kingston, Ontario, Canada
THOMAS A. SCHELLING, University of Maryland, College Park, MD
LARRY L. SMARR, University of Illinois, Urbana-Champaign, IL
STEVEN M. STANLEY, The Johns Hopkins University, Baltimore, MD
VICTORIA J. TSCHINKEL, Landers and Parsons, Tallahassee, FL
WARREN WASHINGTON, National Center for Atmospheric Research, Boulder, CO
Staff
STEPHEN RATTIEN, Executive Director
STEPHEN D. PARKER, Associate Executive Director
MORGAN GOPNIK, Assistant Executive Director
JEANETTE SPOON, Administrative Officer
SANDI FITZPATRICK, Administrative Associate
ROBIN ALLEN, Senior Project Assistant (BOND)
Page v
Acknowledgments
The Board is deeply indebted to the following group of scientists for their contributions to this report:
JUDITH LEAN, Naval Research Laboratory, Group Chair
DANIEL BAKER, University of Colorado
MARVIN GELLER, SUNY at Stony Brook
THOMAS POTEMRA, The Johns Hopkins University
GEORGE REID, National Oceanic and Atmospheric Administration
DAVID RIND, National Aeronautics and Space Administration
RAYMOND ROBLE, National Center for Atmospheric Research
ORAN WHITE, National Center for Atmospheric Research
DONALD WILLIAMS, The Johns Hopkins University
RICHARD WILLSON, Jet Propulsion Laboratory
GEORGE WITHBROE, National Aeronautics and Space Administration
DONALD WUEBBLES, Lawrence Livermore National Laboratory
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The National Academy of Sciences is private, nonprofit, self-perpetuating society of distinguished scholars engaged in scientific and engineering research, dedicated to the furtherance of science and technology and to their use for the general welfare. Upon the authority of the charter granted to it by the Congress in 1863, the Academy has a mandate that requires it to advise the federal government on scientific and technical matters. Dr. Bruce Alberts is president of the National Academy of Sciences.
The National Academy of Engineering was established in 1964, under the charter of the National Academy of Sciences, as a parallel organization of outstanding engineers. It is autonomous in its administration and in the selection of its members, sharing with the National Academy of Sciences the responsibility for advising the federal government. The National Academy of Engineering also sponsors engineering programs aimed at meeting national needs, encourages education and research, and recognizes the superior achievements of engineers. Dr. Robert M. White is president of the National Academy of Engineering.
The Institute of Medicine was established in 1970 by the National Academy of Sciences to secure the services of eminent members of appropriate professions in the examination of policy matters pertaining to the health of the public. The Institute acts under the responsibility given to the National Academy of Sciences by its congressional charter to be an adviser to the federal government and, upon its own initiative, to identify issues of medical care, research, and education. Dr. Kenneth I. Shine is president of the Institute of Medicine.
The National Research Council was organized by the National Academy of Sciences in 1916 to associate the broad community of science and technology with the Academy's purposes of furthering knowledge and of advising the federal government. Functioning in accordance with general policies determined by the Academy, the Council has become the principal operating agency of both the National Academy of Sciences and the National Academy of Engineering in providing services to the government, the public, and the scientific and engineering communities. The Council is administered jointly by both Academies and the Institute of Medicine. Dr. Bruce Alberts and Dr. Robert M. White are chairman and vice-chairman, respectively, of the National Research Council.
Page vii
Preface
In a series of reports over the past decade, the National Research Council (NRC) has outlined a broad scientific agenda to advance our understanding of the processes of global change. These studies stimulated and nourished the evolution of international efforts centered on the International Geosphere-Biosphere Program (IGBP) and the World Climate Research Program and in our own country supported the development of the U.S. Global Change Research Program. As these programs move rapidly from concept to implementation, the NRC Board on Global Change (BGC) has continued to assess critically the scientific needs. Is the scientific agenda truly comprehensive? Are the priorities appropriate in terms of needs for understanding, scientific opportunities, and technological possibilities? Are there gaps that should be and could be filled? Can recommendations be usefully sharpened and focused?
To address such questions, our Board organized extended ad hoc consultations in a few selected problem areas with informal groups of experts from the scientific community. We focused on problems that were fundamentally important to the program's goals, but were not yet being effectively addressed within the program. Solar influences on the Earth system clearly constituted one such issue. The Sun's energy makes life on this planet possible. Interactions between solar energy and the radiative properties of the atmosphere maintain an equable climate through the greenhouse effect, and there is much concern about human-induced changes in the atmosphere. But the Sun itself is known to vary significantly
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in its activity. What are the implications of these changes for an already changing planet?
These considerations led the planners of the USGCRP to include solar influences as a major element of the science program. However, the research agenda was at the time relatively undeveloped. What specific research initiatives could be proposed to fill this gap and to improve understanding of the role of the Sun in global change?
In 1990, our Board requested the assistance of a talented group of active research scientists led Dr. Judith Lean of the Naval Research Laboratory to address these issues. Her group was asked to assist in developing a brief report identifying those aspects of research on the Sun and its interactions with our planet that would contribute to an understanding of global change, together with scientific approaches to developing research plans. It was hoped that these ideas would be useful to the federal agencies as they formulated plans for the U.S. Global Change Research Program.
We are very grateful to Dr. Lean and her collaborators for working with us to develop a set of specific foci for research in this central problem area. We also wish to thank the following individuals:
Dr. Jack Eddy provided the inspiration for this report. The indication that the Sun may be important for the Earth is his vision, carried through the past two decades. His initial concepts, carefully documented in the 1982 Academy Report on Solar Variability, Weather and Climate, laid the groundwork for this more recent assessment of the relationship.
Donald Williams and members of NRC's Committee on Solar Terrestrial Research (CSTR), which together with the Board on Global Change sponsored the ad hoc Group on Solar Influences on Global Change, provided useful critical comments on a draft of the report.
Valuable comments were also provided by many members of the solar and terrestrial research communities, including Linwood Callis, Gizella Dreschoff, Rolando Garcia, John Harvey, James Hecht, Thomas Holzer, Lon Hood, Charles Jackman, Robert Meier, Brian Tinsley, and Edward Zeller. Gary Rottman provided preliminary SOLSTICE data.
Page ix
We also appreciate the work of Dr. John S. Perry, Mr. Donald Hunt, and Ms. Claudette Baylor-Fleming of the NRC staff in supporting this effort.
Edward A. Frieman, Chairman
Board on Global Change
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Contents
EXECUTIVE SUMMARY |
|
Scientific Conclusions |
|
Recommendations |
|
1 INTRODUCTION |
|
The Coupled Sun-Earth System |
|
Global Change Research |
|
Solar Influences on Global Change: A Major Scientific Research Element of the USGCRP |
|
Objectives of the Report |
|
2 SOLAR VARIATIONS AND CLIMATE CHANGE |
|
Background |
|
Total Solar Irradiance Variability |
|
Contemporary measurements |
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Implications from observations of solar surrogates |
|
Geophysical proxies |
|
Evidence from observations of Sun-like stars |
|
Solar Forcing of Climate Change |
|
Solar irradiance changes and the relatively recent climate |
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Solar activity cycles and the weather |
|
Insolation changes due to orbital variations |
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3 SOLAR VARIATIONS, OZONE, AND THE MIDDLE ATMOSPHERE |
|
Background |
|
Solar Ultraviolet Radiation |
|
Measurements of solar UV spectral irradiance |
|
Irradiance variability parameterizations |
|
Energetic Particles |
|
Solar proton events |
|
Relativistic electrons |
|
Galactic cosmic rays |
|
Solar Forcing of the Middle Atmosphere |
|
Effects from variations in UV irradiance |
|
Effects from solar proton events |
|
Effects from relativistic electron precipitation |
|
Ultraviolet Radiation Reaching the Biosphere |
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4 SOLAR VARIATIONS AND THE UPPER ATMOSPHERE |
|
Background |
|
Solar EUV and UV Radiation |
|
Measurements of solar EUV spectral irradiance |
|
Irradiance variability parameterizations |
|
Auroral Particle and Electric Field Inputs |
|
Global Currents and Electric Field Couplings |
|
Global circuit processes |
|
Electric couplings between the upper and lower atmospheres |
|
Solar Forcing and Global Change within the Upper Atmosphere |
|
Couplings of the Upper Atmosphere to the Lower Atmosphere |
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5 SOLAR VARIATIONS AND EARTH'S NEAR-SPACE ENVIRONMENT |
|
Background |
|
The Solar Wind and the Earth's Magnetosphere |
|
Solar Eruptive Events and Geomagnetic Storms |
|
Terrestial Impacts |
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6 UNDERSTANDING THE VARIABLE SUN |
|
Background |
|
Origins of Solar Variability |
|
Relationship between Solar Surface Structure and Energy from the Sun-as-a-Star |
|
Radiation |
|
Plasma and particles |
|
Cosmic rays |
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Requirements for Improved Understanding |
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Present |
|
Past |
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Future |
|
7 RESEARCH STRATEGIES |
|
Monitoring Solar Forcing |
|
Total solar irradiance |
|
Solar spectral irradiance |
|
Energetic particles |
|
Ground based solar variability indicators |
|
Monitoring Terrestrial Solar Effects |
|
Lower atmosphere |
|
Middle atmosphere |
|
Upper atmosphere |
|
Understanding Solar Influences on Global Change |
|
Studies of present day behavior |
|
Records of the past |
|
Understanding and Predicting Solar Variability |
|
Programmatic Approach |
|
Need for interdisciplinary efforts |
|
Connections to other areas of the USGCRP |
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