by Sarah Dry
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Ever on the lookout for opportunities to do more observations, Malkus quickly realized that hurricane studies could be a continuation of her cloud studies by other means. A new opportunity presented itself in the wake of a series of natural disasters. In 1954 and 1955, a series of harsh hurricanes pummeled the East Coast of the United States. In quick succession, hurricanes Carol, Edna, Hazel, Connie, and Ione battered the coast, destroying more than six billion dollars’ worth of property (in 1983 dollars) and killing nearly 400 people. In response, Congress appropriated funds for a National Hurricane Research Project (NHRP), to be headed by Robert Simpson, a meteorologist who had been a forecaster during the war and had helped set up a wartime weather school in Panama. Intervention was written into the plans for this government laboratory just as it had been for the first supercomputers.54 The mission was explicitly tasked with studying how to modify hurricanes artificially, along with more basic research into the formation, the structure and dynamics, and the means of improvement of forecasts of hurricanes. The new funds meant airplanes and airplanes meant government scientists could now, for the first time, do in situ cloud studies on tropical clouds that stretched from the surface of the ocean all the way up to the troposphere.
Malkus saw that the NHRP could be a platform for a more genuinely experimental research program into the link between cloud and atmospheric dynamics she had been hoping to pursue. In 1956, she flew to Miami, where she met Bob Simpson for the first time. Here, finally, was a chance to help turn meteorology into an unambiguously experimental field science, with the rigor and attention to documentation and control that had been missing from most previous cloud-seeding projects.
While the NHRP was established in an attempt to distinguish hurricane research from the seat-of-the-pants, under-theorized, and overhyped work done by Schaefer, it was impossible to start with a clean slate. The memory of the hurricane that had slammed into Georgia possibly as a result of intervention was fresh, and when it came time to draw the boundaries within the Atlantic where hurricanes would be fair game for intervention, an excess of caution was applied. The result was that only one or two hurricanes a season passed through the area in which seeding was allowed.
Still, the chance to use the new instrumented aircraft funded by the NHRP was too good for Malkus to pass up, and while she had focused on clouds up until that point, she didn’t see the sense in making distinctions between what were obviously related phenomena. “So I thought, well gee, I’d better get into this too. Hurricanes are, after all, systems of tropical clouds. Systems of tropical clouds that somehow get together and run wild. Why did they happen in that way?”55 She started reading up on hurricanes, and soon she had come up with an idea that linked the hot-tower hypothesis she and Riehl had developed with the formation of hurricanes.
She was fascinated in particular by the “calm central eye, surrounded by furious winds.” What, she wondered, explained this phenomenon? Relatively little was known about hurricanes, because radiosonde and aircraft sounding were scant. She pored over the data there was, including a film made by MIT which pioneered the use of weather radar to probe the eyewall of the 1954 hurricane Edna. Looking carefully at the film, she realized that most of the air in the hurricane eye came from the cloudy eyewall.56 With Riehl, she developed a model of how a hurricane develops which emphasized the importance of the ocean as an “extra” heat source.57
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At the same time that Malkus was using hot towers to think about hurricane formation, Robert Simpson had begun developing his own theory about how to modify hurricanes. He thought that if you could seed certain key clouds (equivalent to hot towers) in the eyewall, then you could force it to re-form farther out in the storm, thereby reducing the intensity of the wind and weakening the storm. On September 16, 1961, Robert Simpson was able to test his theory when a naval aircraft dropped eight canisters of silver iodide into the eyewall of Hurricane Esther. Instead of continuing to grow as it had been, the storm maintained a constant intensity. Thanks to the coordinated observations of crew aboard six airplanes monitoring the storm, the response of the storm to the seeding was recorded in great detail. These synchronous radar observations showed that kinetic energy had been somewhat reduced in the eyewall. The next day, another load of canisters was dropped, but they missed the eyewall. Subsequent observations indicated that the storm had retained the same intensity it had after seeding the day before. From the difference in the storm’s evolution in response to seeding and no seeding on successive days, they deduced that the seeding had been successful. In an article for Scientific American, the two researchers wrote with no small measure of pride that instead of “merely observing” the formation of a hurricane, they had attempted to “interfere in a critical area with the delicately balanced forces that sustain a mature hurricane.” They took some pains to point out the novelty of the work, noting that their experiments were among the few “ever performed on an atmospheric phenomenon larger than a single cumulus cloud.” Despite the potential risks, there were good reasons to experiment with hurricanes, not all of which involved modification. Better forecasting seemed an almost guaranteed outcome once hurricane research had graduated from an “observational discipline to an experimental one.”
But forecasting was only the start. Hurricanes were the perfect place to test assumptions about weather and climate triggers. Precisely because they are so massive, any attempt to modify one will fail unless it is precisely targeted. Failure to modify, then, would prove a theory’s limitations, while successful modification would mean the theory was likely correct. For this reason, attempts at hurricane modification seemed like ideal tests of hurricane theory, with the bonus that if the theory proved good enough and a hurricane could be precisely targeted, truly staggering amounts of energy would be within human control. In practice, it was extremely difficult to know if in fact an intervention had been successful. If you don’t know what it would have done otherwise, how can you know if you have changed a hurricane’s behavior?
There was a paradox here. Successful intervention required precisely the advanced understanding of hurricanes that such an intervention was designed to help generate. Despite this limitation, those in charge of government funding deemed the seeding of Hurricane Esther a success. Soon after, a new project was established which was explicitly, and solely, aimed at modifying hurricanes: Project Stormfury, founded in 1962 as a joint undertaking of the U.S. Navy and Department of Commerce. Malkus’s numerical cloud models were critical to the justification of the project, providing a tool for testing assumptions and generating predictions against which modification attempts could be checked.
Malkus herself had mixed feelings about weather modification. Though she was attracted by the research possibilities and the more distant potential for humanitarian applications, she was also wary of the corners that were often cut when it came to cloud seeding. Asked in 1961 to comment on the potential for hurricanes to be diverted, she said, “I wouldn’t say we’re on the threshold, but weather control is not a totally ludicrous idea.”58 The problem was that interventions were often staged “with too many claims, with an underestimation of the enormous natural variability of the system, and with impatience on the part of the management to get a positive result in a short period of time.”59
Despite her doubts, two things convinced her to come on board as an advisor. The project was relatively inexpensive and had potentially huge benefits to humanity. And, just as importantly, Stormfury offered a way to improve her models and learn more about hurricanes. “I believed the Stormfury Project would be the only way I could do the experiments on cumulus clouds which I had been thinking about for some time.”60 Rather than trying to seed hurricanes in order to modify their courses, Simpson saw seeding as a tool for doing experiments in the atmosphere. “People should be placing their emphasis on weather modification as atmospheric experiments and I’ve said so all along.” While it was feasib
le to change the development of individual clouds with seeding, the modification of hurricanes with the intention of benefiting humankind was, she thought, always a “very long shot.”
With this in mind, Malkus signed on to Project Stormfury. The plan was to bend the practical goals of project to her own scientific aims—to make of modification both a scientific tool and a practical intervention. She would never otherwise be able to muster the number of aircraft necessary to monitor an experiment well enough to determine if it had been successful.61 In 1963, she got exactly what she wanted, when she carried out a seeding experiment that “changed my life and that of many others.”62 Stationed in Puerto Rico in mid-August of that year, Malkus and the rest of the Stormfury team were waiting for Hurricane Beulah to develop an eye well-formed enough to be modifiable. In the lull before the storm, Malkus saw a chance to test her ideas about cloud growth.63
During the experiment, a total of six aircraft and several dozen technicians enabled Malkus to make successful measurements on eleven non-hurricane clouds, of which six were seeded and five were controls. “When that first cloud exploded,” she remembered, “I was never more excited in my life.”64 The scientists and crew of the several aircraft also broke into wild celebrations on seeing the growth. All save one of the seeded clouds grew explosively, while the control clouds did not. The results were just as Malkus’s model had predicted. She had managed to do what she had long hoped for—to use seeding as a tool for atmospheric experimentation, and to get the full force of the navy’s aircraft backing her as she did so.
Malkus and Simpson published the results of their cloud-seeding efforts in Science, and the magazine put a dramatic series of pictures of the exploding clouds on its cover in the summer of 1964. The response from the public was instant and intense. It was, in Malkus’s words, “an immense storm” for which neither of them was prepared. The “intensely interesting effects” that had been produced in the seeded clouds stoked hopes and fears that the time for weather control had finally arrived. Some greeted the arrival of a hoped-for utopia of weather control, while others saw a repeat of the hubristic meddling with nature that had led to the bomb.
FIG. 5.9. Cover of Science for August 7, 1964, illustrating the results of Joanne Malkus and Robert Simpson’s cloud-seeding experiment.
As exciting as it had been to watch the seeded clouds surge upward, Malkus and Simpson were careful to make it clear that the most significant outcome of the experiment was not the explosive growth but the demonstration that the experiment itself was possible. They wrote an article for Scientific American explaining the nature of the cloud-seeding experiments and trying to pin down the meaning of control. On the one hand, the seeding had shown that “now a real atmospheric phenomenon is at last subject to a relatively controlled and theoretically modelled experiment.” It was true, they thought, that clouds could finally be turned into experimental subjects. But the kind of control needed for scientific experiment was preliminary to—and less complete than—that needed to be able to manipulate hurricanes to human ends. That kind of control—what Malkus and Simpson called “real control”—would be longer in coming. Rather than a giant leap forward, they cautioned that “here meteorology is taking the first small steps toward becoming an experimental science, which it must become if man is ever to exert real control on this atmosphere.”65
The navy and the Department of Commerce were not interested in theoretical models but in modifying real hurricanes. The same weather system that had enabled Malkus and Simpson to test their model using cloud seeding also proved amenable to more practically oriented interventions. Just a few days after the successful cloud seeding, Hurricane Beulah had obligingly developed a more mature eyewall. The entire hurricane—not just a nearby cloud—was now ready for seeding. Using many more aircraft and significantly more silver iodide to massively seed the eyewall, the navy pulled out the stops to see if modification was possible. On the first day that seeding was attempted, the special silver iodide bombs missed the eyewall and no effects were seen. The next day conditions for seeding had improved, and this time the bombs hit their target. Measurements of the core of the storm showed that the pressure dropped precipitously following the second seeding and the cloud pattern of the storm changed dramatically, with the eyewall dissipating and forming ten miles farther away from the center of the storm, much as Malkus and Simpson had predicted.
Despite the seeming success, it was impossible to say on the basis of one modification attempt whether the seeding had definitely caused the changes to the hurricane. The natural fluctuations of hurricanes were so big, and the nature of cloud patterns so little understood, that much remained unknown. Repeating the experiment was one way to test the hypothesis, but given how much these storms varied naturally, it could take centuries to “separate statistically the man-made changes from the large natural fluctuations.”66
In 1964, the National Academy of Science (NAS) convened a panel on weather modification to provide advice on how best to proceed in an area that was both scientifically and ethically challenging. Malkus was a member of the panel, along with Jule Charney, Ed Teller, Ed Lorenz, Joe Smagorinsky, and others. The panel cautioned against haste and noted that evidence to support the efficacy of seeding remained thin. There was as yet no data to suggest, for example, that so-called winter orographic storms, such as those in Colorado which were the subject of great interest on the part of farmers and ranchers in the state, could be made to produce significantly more rain, nor that hurricanes could be steered, nor that black dust or other surface coverings could produce rain. The evidence did not exist to support a leap into weather modification on an operational basis. Most present efforts were characterized by a “seed first, analyze later” approach from which very little reliable information could be gleaned. Patience, counseled the panel, was needed. It could take decades, not years, before the physics was well-enough understood to support widespread weather control. A split developed between research scientists and state legislators of arid states, some of whom accused the scientists of being more interested in producing papers than water.67 Much remained unresolved, even as experts like Malkus gave good reasons to proceed cautiously. In the same year that the NAS panel advised restraint, Congress passed a special resolution appropriating $1 million for operational weather modification programs.
The first small steps toward “real control” of the weather which Malkus and Simpson described in 1964 are today reminiscent of those taken most famously by Neil Armstrong five years later as he stepped onto the moon. But it was to another momentous speech that the scientists may have been referring. That speech, given by President John F. Kennedy on July 26, 1963, occurred just weeks before the cloud-seeding experiments were carried out. In the televised address, Kennedy, speaking in a measured voice in a tone of somber hope, announced the partial ban on nuclear tests in the atmosphere, ocean, and outer space that he and Soviet statesman Nikita Khrushchev had been able to engineer after years of difficult negotiations. Kennedy called the agreement a “shaft of light” in a time otherwise characterized by suspicion and tension, and “an important first step—a step toward peace—a step toward reason—a step away from war.” He reiterated the metaphor in the closing lines of his speech, ending with what felt like an audacious hope: “and if that journey is a thousand miles, or even more, let history record that we, in this land, at this time, took the first step.”68
For Malkus, life changed dramatically in 1965. She had left Woods Hole in 1961 to take a position at the University of California, Los Angeles. That same year, she gave birth to Karen, her daughter with Willem. In the meantime, her relationship with Bob Simpson, which had developed over the course of the shared work at the NHRP and on Project Stormfury, turned into something deeper. The cloud-seeding experiments and the modification of Beulah gave rise to what Malkus called the “Malkus/Simpson collaboration and increasing close friendship.”69 In 1964, Malkus divorced Willem Malkus and left he
r tenured position at UCLA for a research position at the U.S. Weather Bureau. That career move, an unlikely one at first glance, was necessary because nepotism laws prevented a husband and wife from working at the same institution. On January 6, 1965, Joanne and Bob Simpson were married. With the wedding, Joanne took the name of Joanne Simpson and the directorship of Project Stormfury, at the Weather Bureau. Thus began what she called her second great love, and a partnership of mind and spirit that would last until her death.
If Joanne Simpson had finally found contentment in her personal life, the controversy over weather modification raged on. In 1963, she had celebrated in the skies above Puerto Rico as she watched the seeded clouds explode upward, and shared in the sense that hurricane modification was possible when Beulah seemed to respond to seeding. The Stormfury hypothesis that seeding the supercooled water around the eyewall of a hurricane could cause it to release latent heat and migrate outward, weakening the storm, seemed to be correct. These early days of optimism and excitement turned out to be misplaced. Circumstances would conspire to make it impossible to carry out the research necessary to determine whether the hypothesis was, indeed, correct. As difficult as it was to coordinate six or even ten aircraft flying through a hurricane, it turned out to be much more difficult to create a statistically powerful enough program of experiments to tame the natural variability of these great storms. Hurricanes are extremely variable objects. In order to understand their motions—both natural and modified—it is necessary to study a lot of them. This is always an expensive undertaking, and sometimes an impossible one. From 1963 until 1968, no eligible storms passed through the experimental area. Meanwhile, the controversy over weather modification continued. By 1967, Joanne Simpson, no longer willing to put up with the tension surrounding the program, resigned. Stormfury continued, with uneven but ultimately unconvincing results. When, in 1969, Hurricane Debbie finally obliged the researchers and five seeding runs were made, the results were deemed consistent with a revised Stormfury hypothesis (which required less instability in the eyewall and deployed massive, repeated seeding just outside the eyewall instead). But eligible hurricanes that passed through the safe zone remained frustratingly rare, making it impossible to further verify the eyewall hypothesis. Over the course of the 1970s, research into hurricane modification tailed off, and when eventually the project was canceled in 1983, it was deemed a failure.