Joseph Pedlosky

2011 Maurice Ewing Medal Winner

Joseph Pedlosky was awarded the 2011 Maurice Ewing Medal at the AGU Fall Meeting Honors Ceremony, held on 7 December 2011 in San Francisco, Calif. The medal is for “significant original contributions to the scientific understanding of the processes in the ocean; for the advancement of oceanographic engineering, technology, and instrumentation; and for outstanding service to the marine sciences.”


Joseph Pedlosky is a giant in physical oceanography. He has made fundamental contributions to the theories of ocean circulation and has defined the field of geophysical fluid dynamics. His contributions to the field are not just from his 150 papers. His shaping of the fields of geophysical fluid dynamics, ocean circulation theory, and waves and stability is holistically presented in his three textbooks. Pedlosky is one of the few physical oceanographers whose work has had a huge influence not only in physical oceanography but also in other related fields, such as atmospheric sciences, planetary sciences, and, more generally, geophysical fluid dynamics. His most important contributions are in two areas.

The first area is theories of ocean general circulation. Pedlosky has made many pioneering contributions to the fundamental theories of ocean general circulation. Early on, he provided a novel explanation for the western intensification of ocean circulation in terms of the reflection properties of Rossby waves. This theory first demonstrates the physical process leading to western boundary intensification, a fundamental phenomenon in ocean general circulation. Later, he provided the theoretical foundation of laboratory experiments for oceanic circulation. He produced a theory for the nature of boundary layers in rotating stratified fluids and their application to coastal upwelling in linear and nonlinear models. In the 1980s he and his colleagues made a fundamental contribution to physical oceanography by developing the theory for the ventilated thermocline, laying the foundation for the modern dynamics of ocean general circulation.

The second area is instability theories in the ocean, atmosphere, and, more generally, rapidly rotating fluids. Pedlosky has proven several fundamental theorems regarding the instability of oceanic and atmospheric flows and produced the first model of a natural mode of instability that mimics the energy cycle of the oceanic eddies and atmospheric flows. He provided theories for spatial development of instabilities in the ocean and the radiation of energy to regions far from unstable currents. He presented the first deductive model of nonlinear baroclinic instability without friction and the first deductive model demonstrating the chaotic behavior of weakly nonlinear instabilities.

In addition to these original research studies, Pedlosky has made fundamental contributions to the overall development of the field of physical oceanography and related fields by writing several monumental monographs. His book Geophysical Fluid Dynamics provides the first systematic synthesis of almost all the fundamental theories of the dynamics of rapidly rotating fluids, such as the ocean and the atmosphere, and has been the educational foundation for new generations of physical oceanographers, meteorologists, and geophysical fluid dynamists worldwide. This book has been ranked as one of the top cited references in all the fields of geophysical fluid dynamics. His other books on ocean dynamics are also regarded as classical texts and reference books for the teaching and study of ocean circulation and waves. Finally, with his passion and devotion to education, Pedlosky has been a role model for educators through his exceptional lecturing and mentoring abilities.

His fundamental contribution has been recognized by numerous prestigious awards and memberships, including the Meisinger Award and the Sverdrup Gold Medal of the American Meteorological Society; a Fellow of AGU; a member of the National Academy of Sciences and the American Academy of Arts and Sciences; and a Foreign Member of the Earth and Cosmic Sciences section of Academia Europaea.

—Zhengyu Liu, Center for Climate Research and Department of Atmospheric and Ocean Sciences, University of Wisconsin-Madison; and Paola Cessi, Scripps Institution of Oceanography, University of California, San Diego, La Jolla


I am deeply honored by the Maurice Ewing Medal. The vast scope of Maurice Ewing’s contributions can only make me feel humble in comparison.

As always, I am grateful to my mentors: Jule Charney, Melvin Stern, Eric Mollø-­Christensen, and Harvey Greenspan. Some of them are, alas, now beyond my power to thank directly. My gratitude to my colleagues at Massachusetts Institute of Technology, University of Chicago, and Woods Hole extends to too many people to be able to name them all at this time, but my debt to them is immense. I am delighted to express my gratitude to all my students for the pleasure to have seen them flourish as keen, independent scientists and, particularly tonight, to Zhengyu Liu and Paola Cessi, who jointly nominated me for this award and collaborated to produce the very generous award citation.

Now, though, I want to thank a very special person: my wonderful wife, Holly. I have observed in the past that usually thanks are given to a spouse for putting up with an absent partner who spends many late nights in the lab or weeks at sea. As a theoretician, and one with limited mental stamina, I rarely worked in the evenings or on weekends, although brooding over a problem, or lack of one, can be full-time. We know the cycle of theoretical work: formulation, painful perplexity, the occasional epiphany, and the repeat of the cycle. What is less commented upon is the theoretician’s anguish in searching for a new, good problem. The fear that the last good problem is in fact the last good problem is oppressive. Reassurance that one has always found a new problem before is not convincing, because that speaks to history and not to the future. When Holly becomes aware that I am particularly grumpy, she knows it is because I am in that oneiric, half-awake state of confusion and anxiety. Somehow, for all these years, she has patiently helped shepherd me to the other side of that abyss, where I can emerge into the desired state of constructive perplexity. So I think she deserves most of the credit this evening.

One final thought: The calculation of the probability of intelligent life in the universe is a difficult one. A nearly infinite number of possible host planets and a near-zero probability of intelligent life on any one of them means that the product could indicate a single event: ours. After all, even here, the lengthy age of the dinosaurs produced no paintings of sunsets, no formulation of the Navier-Stokes equations (we had to wait for Navier and Stokes). If that is so, and we are alone in that regard, our responsibility is immense. It means that the universe is only conscious of itself by our agency. If we were not here, the universe would be like a cinema showing Casablanca on an endless loop to an empty theater. It is only through us that the universe can be self-aware, and if we were to blow ourselves up or render our planet uninhabitable for anything but the cockroaches, the universe might as well be empty.

We are often asked to describe the larger consequences of our work. I know of nothing more noble and important than serving as the self-awareness of the cosmos. Further, it is our communal effort, and especially for us as scientists it is one we need to take as a sacred trust. I am proud to be part of that effort and to place my small contributions into that mosaic of understanding we are constructing together.

Thank you.

—Joseph Pedlosky, Woods Hole Oceanographic Institution, Woods Hole, Mass.