Arnold L. Gordon

1999 Maurice Ewing Medal Winner

Lamont-Doherty Earth Observatory and Columbia University, Palisades, New York

Arnold L. Gordon was awarded the 1999 Maurice Ewing Medal at the AGU Fall Meeting Honors Ceremony, which was held on December 15, 1999, in San Francisco, California. The medal recognizes significant original contributions to understanding physical, geophysical, and geological processes in the ocean; and/or significant original contributions to scientific ocean engineering, technology, and instrumentation; and/or outstanding service to marine sciences. This medal is presented jointly by the U.S. Navy and AGU.


“It is my pleasure and honor to present the citation for Arnold Gordon, winner of the 1999 Maurice Ewing Medal of the American Geophysical Union.

“Arnold Gordon’s research has been and continues to be directed toward observing the ocean circulation and its interaction with the atmosphere. This has involved understanding the ocean’s role in global climate variability on interannual to multidecadal timescales. His research spans scales and oceans: from the meter scale to the global thermohaline circulation; from the hot tropical regions to the cold polar environments. It has produced quantitative information about ocean circulation and mixing, in particular, the thermohaline-driven component. Arnold has investigated a variety of important elements of regional oceanography, for example, the Southern Ocean, South Atlantic, tropical Indian Ocean, and the Indonesian Seas. These in turn have an important bearing on the subject of global ocean circulation and heat and salt fluxes.

“Arnold’s Ph.D. thesis at Columbia University under the supervision of Georg Wüst was a quantitative study of the dynamics of the Caribbean Sea. After receiving his Ph.D. in 1965, he joined the faculty at Columbia, which has been his home ever since. He was awarded the Bryant Bigelow Medal of the Woods Hole Oceanographic Institution in 1984 and is a Fellow in the AGU and American Meteorological Society. Arnold has served in many leadership positions. He was President of the Ocean Sciences Section of AGU and The Oceanography Society. Arnold has served on numerous scientific steering groups related to programs of physical oceanography and climate. He recently chaired the World Climate Research Program’s CLIVAR Program Science Steering Group. CLIVAR is a new international climate research activity dedicated to the development of a predictive climate model for interannual to century timescales. As a follow-up to the Tropical Ocean-Global Atmosphere and World Ocean Circulation Experiment this program promises to be a primary driver of climate and oceanographic research for the next 15 years.

“Arnold Gordon has made substantial original contributions described in more than 150 publications. Yet his work goes well beyond that; he has defined whole new directions of oceanographic research. Arnold reinstilled community interest in the South Atlantic—a region studied by his mentor, Georg Wüst, in the 1920s. He led the Office of Naval Research South Atlantic research program in the 1980s, with emphasis directed toward the confluence of the Brazil Malvinas Currents and the Agulhas Retroflection. Some of the highlights of this work include an understanding of the contributions of the eddies formed in the region to the dynamics of the circulation and interocean transport.

“In a controversial paper published in the mid-1980s, Arnold related the importance of the Indonesian throughflow and Indian Ocean warm/saline water injection into the South Atlantic to the global thermohaline circulation. By doing so, he turned the community’s attention to the potential climate significance of interocean and interhemispheric transport. Much of this research was carried out thanks to Arnold’s persistent diplomatic work as the main U.S. coordinator for oceanographic research within Indonesia. Gaining access to the Indonesian Seas for U.S. investigators was no easy task; it required 6 years of dedicated effort. The first joint U.S.-Indonesian program was carried out in 1991 and was followed by larger, collaborative programs. Some of Arnold’s significant contributions that followed from this work include recognition of the importance of modification of properties (e.g., heat and salt) by mixing within the Indonesian Seas, the sources and pathways of flow, and quantification and characterization of throughflow variability.

“Arnold’s research has had a major impact on our understanding of the Southern Ocean, the main region of bottom water formation in the world’s oceans. He began organizing expeditions in the mid-1960s as part of the Eltanin circumpolar survey and continued long after Eltanin was decommissioned. Most of these expeditions are joint international programs. During the 1980s his work concentrated on obtaining data in those hard-to-reach places well within the pack ice in nonsummer months. These studies revealed the key role of oceanic heat flux in controlling the distribution and thickness of the sea ice cover. A recent program organized by Arnold, the U.S. Russian Ice Station Weddell, constituted the first scientific ice station of the Southern Ocean and first exploration of the western edge of the Weddell Sea. This scientifically and logistically complex program revealed the formation of two types of Antarctic Bottom Water and led to improved estimates of bottom water formation there. He continued these efforts by leading the AnZone research group for climate-based Southern Ocean research, which develops internationally coordinated Southern Ocean fieldwork.

“Arnold Gordon’s nearly 40 years of outstanding scientific contributions have had a significant and large-scale impact and, together with his tireless and exhaustive service to the oceanographic community, exemplify exactly what the Ewing Medal is intended to recognize and honor.”

—RANA A. FINE, University of Miami, Fla.


“I very much appreciate the recognition that this wonderful Ewing Medal conveys. I thank AGU and ONR for this honor, which is particularly appreciated, because this is the 50th anniversary of Ewing’s legacy, Lamont-Doherty Earth Observatory.

“Real-life experiences can’t be rerun under different conditions, so I can never be sure if the Ewing style determined the way I approach my research or if it was something more innate in me; the two are certainly similar. I love to explore, to go to ocean areas that have been ignored, to gather reams of data, to make stories of how I think the ocean ‘works.’

“Ewing’s style was to collect data every day, if you needed it or not; time has proven that they were needed and still are needed. His realm was the world ocean; he was ‘global’ before global was ‘cool.’ From observations coupled with a bit of creativity, stories evolve. They are attacked, and, in the process, the curious personalities of scientists are revealed. A story may be shown to be a fable or open new ways to think about our world, but at the very least it gets the community’s attention, encouraging more targeted observations and models and, one way or another, advancing the frontier of knowledge.

“I clearly remember the day in February 1961 when I first saw Lamont. The facility was only 12 years old then, but to me, even if I were aware of that, Lamont was there forever. I had already assumed I would accept an MIT offer, but an encouraging letter from Jack Nafe brought me to Lamont, way upstate for a Brooklyn boy. I asked Nafe if I could really study physical oceanography at Lamont, a field that I was sure I wanted to study from my early days. He said yes, for, unknown to me at that time, Ewing had already realized he needed physical oceanography to better understand the processes that govern sedimentation in the ocean, and perhaps it would also help in unraveling the mysteries of climate. He had engineered a grant from the Ford Foundation to bring the great German oceanographer, Georg Wüst, to Columbia and pay $1800/year for a graduate student, who turned out to be me; they made me an offer I couldn’t refuse.

“Maurice Ewing was an imposing figure. I remember walking that long hallway—a hallway that seemed to grow longer and longer with every step—to Doc’s office on the second floor of Lamont Hall. From Ewing emanated the Lamont personality: a spartan life of work and dedication, a career driven by an intense need to engage in the quest for clues to understand the Earth. With so little known about the Earth, every measurement made had the potential to uncover something new; the same is true today.

“After receiving my Ph.D. in 1965 with a thesis on the Caribbean Sea, I then turned my attention to the Southern Ocean. I inherited leadership of the Eltanin circumpolar survey project. (Who knew of postdocs in those days?) What better place to be global; all the ocean basins are merely estuaries of the Southern Ocean. Not only is the Southern Ocean a major ventilator of the deep ocean, but it also links these estuaries, allowing interocean fluxes, a critical element in the global climate system. I gradually moved into the South Atlantic, Wüst’s ocean-of-fame. As a young scientist, he was aboard the German research ship Meteor, which crisscrossed the South Atlantic, between 1925 and 1927, producing a data set still very much in use today. My South Atlantic research widened my view of the global network of interocean exchange, a network that is closely linked to deep convection at the head waters of one of those Southern Ocean estuaries, the North Atlantic.

“I extended that theme with fieldwork in the Indonesian Seas. These being the hottest waters and the Southern Ocean being the coldest made the rest of the world ocean simple, assuming linear interpolation, of course.

“In many ways, ship-based oceanography in the 1960s was not too different than it was in the 1920s aboard Wüst’s Meteor. On the Eltanin we remained at sea for 60 days, spending half that time getting to and from the research area. We collected water in Nansen bottles at 23 levels at perhaps only 30 stations, struggling to collect those few samples.

“Today, we sample continuously from sea surface to seafloor at well more than 100 stations in a 30-day cruise. We deploy instrumented drifters and moorings. Satellites provide images of the sea surface temperatures over the entire ocean. They monitor sea level changes and wind stress on the ocean surface and look at sea ice cover hiding under the clouds. When I look now at ocean intricacies exposed by these new observational methods, I wonder if we had known of the ocean’s complexity, might we in the 1960s have been too disheartened to move ahead. I don’t think so: the excitement of discovery outweighed any sense of discouragement.

“Sophisticated computer modeling has become a major tool for investigating the complex dynamics of the ocean and the climate, but the foundation and the validity of any model still rely on actual observations. It’s the combination of models and observations that counts.

“I’ve never lost the feeling that unexpected ‘discoveries’ are still lurking out there. The division between known and unknown in science is not a sharp boundary between light and dark but, rather, a murky region full of speculations and few data, a place where imagination rules. I wonder, have all the stories been told and all that is left is filling in the details and making sure all is properly simulated in computer models? Of course not (or at least I hope not). I’m more concerned that the funding and educational pressures of today may act to discourage field exploration and risk taking, limiting the thrill of discovery. We must find ways to project the Ewing style in a way that is appropriate for today’s world.”

—ARNOLD L. GORDON, Lamont-Doherty Earth Observatory and Columbia University, Palisades, New York