University of Washington, Seattle
James R. Holton was awarded the Roger Revelle Medal at the AGU Fall Meeting Honors Ceremony, which was held on December 17, 2000, in San Francisco, California. The medal recognizes outstanding contributions toward an understanding of the Earth’s atmospheric processes, including its dynamics, chemistry, and radiation; the roles of atmosphere, atmosphere-ocean coupling or atmosphere-land coupling in determining the climate, biogeochemical cycles, or other key elements of the integrated climate system.
“We celebrate the selection of Professor James R. Holton, Chairman of the Department of Atmospheric Sciences at the University of Washington, as this year’s recipient of the AGU Revelle Medal. What is remarkable about Professor Holton’s career and what makes him so appropriate for the Revelle Medal is the combination of intellectual depth in his work in dynamic meteorology and the powerful links that he has forged joining dynamics, chemistry, radiation, and climate.
“The fundamental intellectual contributions to dynamic meteorology include stable finite differencing schemes, diagnostic models of the quasi-biennial oscillation (QBO), Kelvin and Rossby wave interaction with wind field shear, and dynamics of the Intertropical Convergence Zone (ITCZ). A keen sense for the link between observations and theory has set the standard for a generation. Establishment of strong bridges to the adjoining fields of chemistry and climate underscores the breadth of Holton’s contributions. By the mid-1970s, he was confronting the perplexing question of stratosphere-troposphere exchange, a subject that immediately emerged whenever the issue of changes to the atmosphere/ocean system were considered on timescales longer than a few years. Holton attacked the problem of polar vortex stability and the associated questions of sudden stratospheric warming events, laying the foundation for the critical link between the existence of large temperature changes in the lower stratosphere and the highly temperature-dependent heterogeneous reactions that repartition free radical species in the halogen and nitrogen reaction networks in the upper troposphere and lower/midstratosphere.
“In the early 1980s, Holton took on the problem of large-scale flow in the middle atmosphere: exploring the role of forced planetary waves in the annual cycle of the zonal mean circulation, the influence of the QBO on global circulation, the two-dimensional transport of stratospheric trace species, atmosphere-ocean dynamics, and the influence of gravity wave breaking on the general circulation of the middle atmosphere and the meridional distribution of stratospheric trace species. During this period there were also a series of papers extending his analysis to the mesosphere.
“In 1972, Holton authored the text, An Introduction to Dynamic Meteorology, that provided the foundation for linking dynamics with the field of atmospheric chemistry. It came at a time when the need to intellectually join these subjects was becoming very clear. The book was beautifully written, and it remains, through subsequent editions, the standard. In 1987, the text Middle Atmosphere Dynamics was published with Andrews and Leovy as coauthors, thus providing the state-of-the-art intellectual foundation needed to dissect the chemical and dynamical component of the high-latitude winter losses observed in stratospheric ozone-the ‘ozone hole.’ While the severe loss of ozone at high latitudes and its aftermath dramatically changed atmospheric chemistry, perhaps the most permanent change was that it forever joined the fields of radiation, chemistry, dynamics, and climate. At the center of this union was Jim Holton. He became the most sought after source of scientific guidance on issues of dynamics and chemistry.
“During the late 1980s, he made critical contributions to the design of airborne research missions, to the interpretation of satellite results, to the advisory structure of the National Research Council, and to the refereeing of public debates and scientific manuscripts. At the same time, his fundamental contributions continued. He published key papers on the climatology of the polar vortex and planetary wave breaking, on the role of gravity wave-generated advection and diffusion in transport of tracers in the mesosphere, and on the coupling of chemistry and transport on isentropic surfaces, to select a few.
“In the 1990s, Holton continued to attack both the fundamental intellectual issues in dynamic meteorology and specifics of the linkages between dynamics, chemistry, and climate. In 1995, he was the lead author on an AGU review paper, ‘Stratosphere-Troposphere Exchange,’ that has revolutionized the subject across disciplines; it is a classic treatise in the field, setting the context for downward control of the meridional transport pattern of the middle atmosphere, redefining the tropospheric and stratospheric regions according to surfaces of potential temperature and potential vorticity, and placing the mid-stratospheric ‘pump’ as the primary forcing function in meridional circulation.
“The Revelle Medal recognizes intellectual depth and breadth, scientific impact on a number of fields, public service, and unselfish contributions to the foundations of atmospheric and oceanic science. Jim Holton sets the standard.”
—JAMES G. ANDERSON, Harvard University, Cambridge, Mass.
“It is with deep gratitude that I accept the Roger Revelle Medal for the year 2000. I did not have the privilege of knowing Roger Revelle, but was for many years in awe of his very broad-based scientific leadership and statesmanship. It is also a distinct pleasure to be cited by Professor Jim Anderson, whom I have known since childhood. Jim’s father encouraged me to go to Harvard to study physics. There I discovered that my true interest was not in the world of nuclear physics, but rather in the world of the classical physics of the natural environment. As a senior I was fortunate to have the opportunity to be introduced to the physics of the atmosphere by Professor Richard Goody, who had recently arrived at Harvard.
“When the time came to apply for graduate school, my options were limited by the fact that my girlfriend was a Radcliffe undergraduate, and I thus wished to stay in the Cambridge area. Though Professor Goody stated that I would be welcome to stay at Harvard and work under his supervision, MIT offered a better financial package (a fellowship of $3,000 per year). Professor Goody stated that though Harvard was the better choice, if I really wanted to go to MIT, I should study under Jule Charney. This proved to be truly exceptional advice. To many of the younger people in this room, Charney is now just an historical figure, but for those of us who were privileged to ‘sit at his feet,’ he remains a giant who is very much missed.
“After a postdoctoral year in Stockholm, where Bert Bolin introduced me to the strange concept that atmospheric chemistry might be relevant even to a geophysical fluid dynamicist, I joined the Department of Atmospheric Sciences at the University of Washington. One year later, I was joined in Seattle by another MIT graduate, Professor J. Michael Wallace (last year’s Revelle Medalist). During the next few years I had the privilege of collaborating with Mike Wallace and Richard Lindzen on work that led to what is now the generally accepted theory of the quasibiennial oscillation of the equatorial stratosphere. Thus began my career-long interest in the dynamics of the stratosphere.
“I can’t, however, leave the subject of my early career in Seattle without mentioning the strong influence of my senior colleague, Professor Richard Reed. Dick showed me the importance of grounding theoretical models firmly in observations. He also encouraged me to write the textbook, An Introduction to Dynamic Meteorology; a book that has made my name widely known-if not widely loved-among students of the atmospheric sciences.
“In 1980, I was selected as one of the so-called ‘theoretical principal investigators’ on the Upper Atmosphere Research Satellite. So began a 20-year effort to contribute to our understanding of transport processes and their influence on the chemistry of the stratosphere. I have, during this period, enjoyed my association with many fine colleagues in the remote sensing, modeling, and chemistry communities. To all of them, I give my thanks for their friendship and for all that they have taught me.
“Finally, that girlfriend who kept me in Cambridge for my graduate studies-she is my best friend and wife, Margaret, whose love and support have seen me through all the rough spots over the past 40 years.”
—JAMES R. HOLTON, University of Washington, Seattle