Carl Wunsch

2006 William Bowie Medal Winner

Massachusetts Institute of Technology

Carl Wunsch was awarded the 2006 William Bowie Medal at the AGU Fall Meeting Honors Ceremony, which was held on 13 December 2006, in San Francisco, Calif. The medal recognizes outstanding contributions to fundamental geophysics and for unselfish cooperation in research.

Citation

Carl Wunsch is a visionary in the study of the ocean and its roles in climate change. Through the impact of research, vision, leadership, and unselfish cooperation, he has shaped the landscape of modern oceanography.

He started as a mathematician setting out to seek new approaches to studying the ocean and the solid Earth. His early work made fundamental contributions in diverse topics ranging from ocean tides and internal waves to the Chandler Wobble of the Earth. Since his early career, he has been a crusader, advocating statistical rigor in making inferences from observations, a virtue not fully appreciated by the oceanographic community at the time. His work has showed us how to obtain definitive knowledge with quantified uncertainty about the ocean from limited disparate data records.

Furthermore, his work has often led to the development of new strategies and tools for observing the ocean. His contributions to the design of the landmark Mid-Ocean Dynamics Experiment (MODE) and the POLYMODE experiment in the 1970s to determine the scales of ocean variability are notable examples.

In the late 1970s, Carl introduced the inverse modeling method to tackle the problem of ocean circulation as a grossly under-determined system resulting from the extreme scarcity of observations. With the method, he developed a framework for assessing the information content in the sparse observations of the global oceans. Carl’s effort has transformed observational studies of the ocean from qualitative description to quantitative determination. This transformation has also created a new paradigm in which numerical models of the ocean are not just a theoretical tool but also a tool for applying ocean physics to observations for optimal estimation of the state of the ocean. The emergence of ocean data assimilation in the mid-1990s for a wide range of applications was to a large extent owing to Carl’s contributions.

An entire generation of oceanographers has benefited from Carl’s work. I am fortunate enough to be among Carl’s numerous students who can attest to this achievement firsthand. Recognizing the dire need for global ocean observations, Carl inspired the international community to campaign for global programs to observe the oceans, leading to the World Ocean Circulation Experiment (WOCE), the largest international effort to date to measure the flow field and water properties of the world’s oceans. WOCE was developed in the 1980s and successfully carried out in the 1990s. Carl was also the intellectual creator of the highly successful U.S./France joint satellite mission of TOPEX/Poseidon as part of WOCE, for measuring the global ocean surface topography from space. The results from WOCE and TOPEX/Poseidon have revolutionized the way we study the oceans, and set an invaluable benchmark against which we will measure the future change of the global oceans and its effects on climate. For the first time in history, oceanographers can answer questions like, How much change in the ocean circulation and heat storage has taken place in the past decade? What is the uncertainty of the estimate?

Carl’s monumental contributions leading to such a fundamental advancement of a branch of Earth science have fully embodied the ideals of the William Bowie Medal, the highest honor bestowed by the American Geophysical Union.

—Lee-Lueng Fu, Jet Propulsion Laboratory, Pasadena, Calif.

Response

Receiving the William Bowie Medal is both a pleasure and an honor, and I am grateful to Lee Fu and the many others who determined to make it happen. Lee’s nice words are, of course, pleasant to hear, although they make me aware of all of the colleagues, students, and collaborators who should receive much of the credit. My wife, Marjory, will also know how much I owe her.

There is not enough space here to provide an adequate response. In summary, I was very lucky in my career, having been in the right place at the right time. By good fortune, I encountered a remarkable group of senior people who were prepared to foster an inexperienced student and junior colleague. At MIT (Massachusetts Institute of Technology, Cambridge), Raymond Hide sent me to a new faculty member named Henry Stommel. Hank was so exciting and inspiring that I decided I wanted to work with him. That he was a physical oceanographer, and that I knew nothing of the subject, was not really a consideration, for either of us. Ironically, I left geophysics in the midst of the most exciting time in its history—the plate tectonics revolution. I’ve never regretted it!

Physical oceanography as it was practiced in the 1960s and 1970s presented, by today’s standards, some remarkable opportunities. One got to go to sea, to make measurements that were still largely mechanically based and so intuitively understandable, to be paid to visit exotic locations, to construct new and simple theories that seemed to work, and perhaps the ultimate experimental experience, to have control of a large, transoceanic ship and crew for weeks at a time. The world would have been a much better place had there been no Cold War, but the United States Navy was then rapidly building up new oceanographic programs all across the country. They were searching for people and ideas, and the money was there. To give some idea of how different that period was from today, as a 25-year-old new Ph.D., I became the chief scientist on the R/V Atlantis II for 2 weeks working near Bermuda to understand the island/ocean interaction. With hindsight, it’s probably the scariest thing I ever did, and it’s virtually inconceivable today.

Frank Press, who hired me, understood exactly what was required for a young scientist to make his way. Frank showed me how to be a faculty member, how to work with students and colleagues, how to manage a department, and generally how to be a working scientist. He showed me that if one tried to determine what people were good at, and if one helped them to do it, then everyone benefited.

MIT, which gave me my only job, was a very capably run institution, by people including Frank Press, Jerome Wiesner, Howard Johnson, Jay Stratton, Walter Rosenblith, and William Brace. It was an exceptional place to work, an institution where faculty well-being was paramount—if one had a problem, they understood it, and were prepared to help.

Many of the things that Lee credits to me came about because I had the right people to work with. Walter Munk has loomed large in my professional life. To describe what I took from our relationship over the years requires an essay in itself. There have been others over the years, including my engineering collaborator, John Dahlen, my partner in WOCE, Worth Nowlin, and several others in recent years. More generally, my students and postdocs have all been collaborators in many different senses of the word. Programs like the World Ocean Circulation Experiment and TOPEX/POSEIDON only happen from the willing efforts of thousands of people, and when the world is ripe.

Geophysics, in the widest sense of the word, has advanced immeasurably over the past 40 years. Four of the people instrumental in my own career (Press, Hide, Stommel, Munk) became Bowie Medalists. The job of those of us receiving awards and medals for career-long work is to assure that 40 years from now, the winner then of the Bowie Medal will be able to say that he or she likewise benefited from the ungrudging support of those who came before.

—CARL WUNSCH, Massachusetts Institute of Technology, Cambridge.