Waters of the World

by Sarah Dry

  Near the Gulf Stream, rather than decreasing the energy of the Gulf Stream, eddies seemed to be adding to it. In other words, the viscosity of the eddies—that is, the extent to which they acted as a brake or drain on the energy of the system—was found to be negative. Looking at the data, a theoretical oceanographer named Peter Rhines wrote that it was possible to see that “the small eddies have coalesced to form a few lazy gyres. This is just the reverse of the result for totally chaotic, three-dimensional turbulence in which energy is degraded into smaller and smaller eddies until ultimately being lost to viscous smoothing.” Given this surprising and counterintuitive coalescence of eddies, Rhines noted that it would be necessary to rethink our understanding of how turbulence functioned in the ocean. The classic example used to explain turbulence—a cup of tea into which milk has been stirred—was no longer a reliable model. “Clearly the ocean is not a teacup,” concluded Rhines, “and energy put into eddies and intense currents cannot simply flow out of the system into minuscule eddies and thence be dissipated by viscosity.”47

  If eddies were adding energy to the system rather than enabling it to dissipate, then any description of the circulation that simply ignored them (because they were too small to see) would be fundamentally inadequate. Whatever theories existed for explaining the large-scale circulation were suddenly much less secure. Joanne Simpson and other meteorologists had already covered this ground (so to speak), in the air. It had taken roughly fifty years, beginning at the turn of the century, for them to realize that storms in the atmosphere were not merely a means by which the system threw off excess energy. Instead, they came to understand that storms—what we would call “weather”—in fact feed energy back into the system and affect climate on the largest of scales. Rhines imagined what the implications of negative viscosity in the ocean would be for a world circulation. “Eddies, if fast enough, can gang up to drive a systematic flow. It is just possible that the ocean works as a sort of Rube Goldberg device, with the wind driving a strong circulation that breaks down into eddies; the eddies then drift off and radiate into the far reaches of the ocean, where they recombine to drive new elements of circulation. Models of this sort are now being explored.”48

  Personally, Stommel worked hard to reconcile the need for collaboration in order to answer the “big and difficult” problems posed by the ocean with his desire to keep oceanography a bureaucracy-free zone. He characteristically found inspiration in the ocean itself. “We are beginning to see spontaneous and fluid groupings of oceanographers,” he declared hopefully, in a document written for just the sort of government program he might have wished to steer clear of, “whose aim is to grapple with certain long-period and large-scale phenomena in the ocean.” These eddies of researchers come together for time-limited events—called “experiments”—which “the scientists involved expect to carry out themselves.”49 Little autonomy would be lost if these groupings could somehow be relied upon to spontaneously form and dissipate. Though MODE was “a form of Big Science,” he hoped it could be just a temporary form, summoned into being for a “particular job and dissolved in a few years when that job was done.”50 The contrast with studies that, as Stommel put it, “depend on large volumes of data gathered in routine fashion by governmental agencies” could not have been stronger. If Stommel was polite enough to acknowledge that both types of investigation were useful, it was more than clear on which side his sympathies (and creative energies) lay.

  FIG. 6.7. Henry Stommel in conversation with George Veronis. Photo by Vicky Cullen. © Woods Hole Oceanographic Institution.

  All of this research took a toll on Stommel, who was central to the planning of almost all of it and the implementation of a significant portion of it. Stommel, who was accustomed to publishing up to six papers a year (often with coauthors), published nothing at all between 1974 and 1976. It didn’t help that he had been living since 1960 in a self-imposed exile from WHOI, first at Harvard and then for fifteen years at MIT. He had left WHOI in the year that Paul Fye had taken over the directorship of the Institute, having found it impossible to work under him. With Fye in charge, the wolves of bureaucracy seemed to be circling ever closer. This period of creative drought only ended when Fye retired, and in 1978, after eighteen years, Stommel finally felt he could return to his intellectual home at Woods Hole. Then, in his words, “I gave up teaching and all administration and began to live again.”51

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  All of these anxieties about both the changes in how oceanography was practiced and the possibility of understanding the ocean globally were to a certain extent internal to the field of oceanography, reflecting its particular disciplinary history and the coming-of-age of the postwar ambition to create a physical science of the ocean. By the early 1970s, in oceanography as in meteorology, new external pressures were beginning to play a decisive role. The military applications of oceanography that had garnered it funding and prestige during and after the war were, by the 1970s, increasingly being supplanted by the climate-predicting utility of oceanography. By 1974, there was a growing awareness that it would not be possible to understand changes to the earth’s atmosphere as a result of rising carbon dioxide without understanding the ocean as well.52 It was incumbent upon oceanographers to determine how “to make progress toward building their oceanic part of the model,” according to a National Research Council panel on “The Role of the Ocean in Predicting Climate.”53 A steering committee, chaired by Stommel, was set up to investigate the “large-scale ocean-atmosphere coupling (particularly as they relate to the ocean’s effect on climate).”54 The models to which Rhines had referred in his report on the role of eddies in the general ocean circulation were numerical computer models, which had, by the 1970s, assumed a central role in the way climate variability was investigated. At the end of the decade, the National Research Council appointed a committee, which came to be known as the Charney Committee, to consider the role of rising carbon dioxide and major climate change. Stommel was one of three oceanographers in the group. Their report made some guesses about future global mean temperatures and noted strongly that much remained unknown about the ocean’s response to atmospheric warming, its uptake of carbon, and its thermal memory.55

  The drive to consider the ocean as part of a global climate system coincided with the possibility of seeing the earth from space. Such a prospect had been seriously considered ever since 1960, when the TIROS series of weather satellites had returned the first images of cloud patterns taken from space. Oceanographers realized that if satellites could one day provide them with sufficiently accurate measurements of sea surface elevations (to within around fifty centimeters), it would be possible to map the location of ocean currents from space because these currents are warmer than surrounding waters and cause the ocean to bulge upward. Fifteen years later, what had once seemed like science fiction became a reality. In 1975, Geos 3 provided the first comprehensive picture of the ocean geoid, the bumpy average sea level that would be visible if the effects of tides and waves could be magically subtracted from ocean surfaces, leaving only the variable effects of gravity on the ocean. To prove that the data from Geos 3 was good, scientists used it to find a so-called “cold core ring” or eddy, which had been compared with data collected from buoys in the sea, aircraft in the skies, and infrared (versus altimetrical) readings from satellites.56 In 1978, the picture from space got sharper still when SEASAT provided even more precise sea surface readings, revealing the presence of the Gulf Stream.57

  In addition to the new global visions of the oceans that satellites seemed on the cusp of being able to deliver, there was another global ocean that seemed well within reach. This was the global ocean created by the climate modeling community, a fast-growing group of researchers who relied upon advances in computing power to enable them to calculate ever more finely resolved numerical models of the earth, in which the grid which was laid down, numerically, over the earth, became ever tighter. These models held the prom
ise for a new kind of global knowledge in which physical equations mimicked the actions of real water. Without data from the actual ocean with which to check—or calibrate—these models, however, they risked becoming elaborate fictions with no connection to reality. Unlike the velveteen rabbit, the models demanded not love but data to make them real.58

  The same year that Stommel helped chair the NRC panel on ocean-atmosphere coupling, a meeting was held in Miami by a new group called the Committee for Climate Change and the Ocean. The question of the ocean’s role in climate had become increasingly pressing, thanks to the work of the modelers who demanded data to calibrate their tools and to the growing understanding of scientists working in a range of climate-related disciplines that the earth’s climate was a global and coupled system, of which the ocean was a critical component. Building on this growing awareness, oceanographers and other researchers met in Miami to consider climate change and the oceans. There, Carl Wunsch suggested that in order to understand the ocean’s contribution to the climate, it would be a good idea to at least try to measure the ocean circulation globally.59 And so the stage was set for a new project that brought together two important groups of researchers, whose fates would henceforth be intertwined.60 The project brought together physical oceanographers studying the circulation of the ocean as a problem in ocean dynamics alongside newly christened climate scientists (inheritors to some extent of climatologists’ concern with average temperatures), who wanted to understand the relationship between the ocean and the atmosphere as it related to the uptake of man-made carbon dioxide.61

  Like MODE, the new project was also an experiment—the World Ocean Circulation Experiment (WOCE). Also like MODE, it was a program designed to answer a particular question. It just so happened that the question was a big one: What is the nature of the world ocean circulation? The breadth of the question begged another one: Was WOCE really still an experiment, in the sense of a time- and process-focused singular event? Or, to get anywhere close to an answer about the world ocean, would it be necessary to set up a program on such a scale that WOCE would become a newfangled version of the old-style, observation-rich, theory-poor hydrographic surveys?

  Stommel stayed well clear of WOCE. Though he had always been attuned to the ways in which theoreticians, modelers, and observers related to each other, and emphasized the need for close contact between them, the scale of WOCE was too big for him. With MODE, he felt, the size of the project had worked well. But when it came to larger undertakings such as WOCE, the connections between researchers, he feared, became necessarily more rigid and more problematic. The bigger the model, the more observations it required, and the more organization. The way MODE had functioned—“a loose association of individual investigators to raise the neighbor’s barn” is how Stommel put it—would not be sustainable over the time frames needed to support the longer-scale models. “If you think about joining one of these longer-term, big-scale things, you’re really sort of becoming an employee of a construction company. And that’s not very attractive to many of us. We’re a little bit scared of the long-term commitments that might be involved in programs like this.”62

  It took roughly thirty years from the first planning stages until the data from WOCE had been fully analyzed. In the process, WOCE helped transform oceanography. In 1985, it had been hoped that WOCE would “provide the first comprehensive global perspective of the ocean as an element in the planetary climate system . . . the driving force for attempting a WOCE is the recognition that predicting decadal climate change will depend on accurate calculation of changes in the large scale flow of heat, freshwater and chemicals in the oceans.”63 It had achieved this, enabling a simplified but powerful quantitative estimate of the ocean’s role in transporting heat, which could be combined with that of the atmosphere to offer a model of the earth’s climate at the global scale.

  As impressive as this achievement was, perhaps the greatest legacy of WOCE was to more meaningfully reveal the ignorance of oceanographers and what shape a program meant to ameliorate that ignorance might take. Pondering the future of their discipline in the early 1980s, while planning for WOCE was ongoing, Carl Wunsch and Walter Munk had written that “we can now appreciate the magnitude of the job facing oceanographers who wish to understand how the ocean ‘works,’ and who might one day hope to forecast changes in ocean conditions. The ocean is a global fluid, not unlike the atmosphere, and one wishes to observe the global system on all important space and time scales.”64 Envisioned as a snapshot of the ocean of unprecedented scope, WOCE engendered the felt need for a sustained program of global observation. It wasn’t a return to the old survey days but it was, in its own way, a return to the discipline of sustained looking. The difference was that as a result of rising concerns about climate variability, looking had become monitoring. The oceans could no longer be simply a place to search for knowledge (if they had ever been that). They had become a signal of a changing global climate that had to be monitored.

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  Stommel had hoped that WOCE would be the best of both worlds, a blend of the traditional and novel, between the comprehensive and the specific: a compromise between geographically oriented surveys and process-oriented experiments designed to test key physical hypotheses. “Perhaps,” he wrote in a heartfelt 1989 essay, WOCE “isn’t really Big Science at all—just an assemblage of the miscellaneous smaller projects that people would have wanted to do anyway.”65 This sounds like a man trying very hard to convince himself of something. He sounded more convincing when he considered the unknown scientists yet to come, young people who would challenge the accepted notions of his generation, who would risk their own predictions and who might once again remake the oceans in a new image. Whatever form science might take in the future, whatever organizations were deemed necessary to answer the questions scientists seek to pose, Stommel still believed that for any one individual who seeks to do science, it was the personal endeavor, the “wrestling match with some aspect of the universe,” that was the main challenge and central reward. “All alone, one confronts the unknown and divines some meaning from it. We sort the pieces and arrange them in new patterns.” In the ocean, as Stommel knew better than anyone, the pieces are innumerable, the patterns more infinite still.66

  Given the depth of his feeling for what the personal experience of oceanography could be, it is more than a little jarring to listen to Stommel, in a recording made in 1989, sharing his thoughts on the relationship between science and faith. Rather than providing answers to questions that had previously been unthinkable, Stommel here describes science as limited in its scope. “It seems to me that science,” he says, “is really very restricted in what it can tell us about the world, how it can meet our needs, the things that we desperately want to know.” Just three years before his own death at the age of seventy-two, Stommel describes a visit to the deathbed of his friend and mentor Ray Montgomery (the man who had suggested to him back in 1947 that it might be worth considering why streamlines crowd on the west). Stommel asked Montgomery his thoughts on the meaning and wonder of life and what he thought it all added up to. Montgomery replied that his mind was closed on the subject. He offered neither Stommel nor himself any solace in the face of death, remaining steadfast in his refusal to seek the comforts of spirituality. The exchange made a deep and disquieting impression on Stommel.

  If he did not himself reject spiritual values, Stommel was rigorous in separating them from his scientific activity. Though he had spent his life wrestling with—and finding great joy in—the mysteries of the universe as manifest in the ocean, at the end of his life he was adamant that it was dishonest to arrogate to science the kind of wonder long associated with religion. “We have ideas of reverence,” he said, referring to the way people sometimes thought of science as a kind of religion. “We get a great thrill out of going into Westminster Abbey and seeing Newton’s grave and Kelvin’s grave. I regard the library here [at Woods Hole] as some kind of a te
mple. Now what in the world do words like beauty and reverence and temple have to do with science as we know it?” he asked. “I don’t have an answer to that,” he replied, pausing before adding, “This is a subject which troubles me a good deal.”

  By the end of his life, it seems that Stommel’s own desire for wonder had far outstripped his sense that science had any claim to provide it. There are echoes here of Tyndall’s compulsive revisiting of the idea that science produced wondrous things—including the human capacity for wonder—for no reason at all. But while Tyndall never failed to be satisfied with the wonder that his appreciation of nature produced, in Stommel’s remarks there is a sense that his frustration at the limits of science has outstripped his awe at the productions of nature.

  Stommel was in agreement with Tyndall on this materialist point. Science was, he clarified, “like the instructions on a microwave oven.” It was “awfully dry and dead and unkind,” devoid of any of the moral and emotional value that gave human life meaning. The problem was not that science couldn’t deliver these things, but that we made the mistake of expecting it to. Science dazzles us with its successes, Stommel explained, “and then all of our hopes and wishes and anxieties somehow diffuse into it and then we talk about the beauty of science and our love of it and our reverence for it, and there isn’t anything like that in it at all as far as I can see.”

  He hoped that the new limits to what science could hope to know—limits that he himself had helped uncover in the turbulence that lay within the very machinery of the ocean—might help recalibrate the place of science in our emotional landscape. Maybe, in other words, we could learn with time to expect not more but less from science, and to be better off as a result. “My own feeling about science is that for me it’s been useful as a diversion from more important things. It has been a measure of relief from getting crushed by wonder and anxiety. It’s a form of whistling in the dark.”67