Fixing the Sky (30 page)

5.3 Project Cirrus hurricane-seeding experiment and the subsequent path of Hurricane King in 1947 (
solid line
), compared with the path of a 1906 hurricane (
dashed line
) that also had turned suddenly. A retrospective study by the weather bureau showed that upper-level steering currents, not seeding with dry ice, had likely caused the storm to veer suddenly. (SCHAEFER PAPERS)

No one held the “hurricane busters” officially liable, but that would certainly not be the case today. The storm's unexpected turnaround following—if not necessarily because of—seeding dampened GE's hopes of making grandiose claims about storm control. Schaefer participated in a press conference at which evading questions was the order of the day, and he wrote in his official report: “Change in plans of the publicity angles to the project caused considerable delay and should be completely eliminated. This should be done by the assignment of a [public relations officer] to the project if it's again tried.”
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An unrepentant Langmuir admitted, “The main thing we learned from this flight is that we need to know enormously more than we do at present about hurricanes.”
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Langmuir was already looking ahead to future hurricane seasons—he hoped that the Project Cirrus team could intercept hurricanes far out at sea, fly multiple tracks through them, “and see if we cannot, by seeding them, in some way modify or shift their positions.... The stakes are large and, with increased knowledge, I think we should be able to abolish the evil effects of these hurricanes” (185).

Six decades later, the case of Hurricane King might serve as a warning to the Department of Homeland Security, which, as of 2008, wants to fund a new wave of research aimed at weakening the strength of tropical storms and steering them “off course.” But, of course, hurricanes do not run on tracks or on a schedule, so
everyone
damaged by a modified hurricane could sue for damages—unless the government tried to place an embargo on such lawsuits.
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The exciting news from GE about weather control took another step in January 1947 when physical chemist Bernard Vonnegut discovered that molecules of silver iodide act as artificial nuclei and can “fool” cloud water droplets into crystallizing.
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During World War II, Vonnegut worked in the Department of Chemical Engineering at MIT on projects related to gas warfare and with the Department of Meteorology on problems of aircraft icing. He moved to GE in 1945 and worked closely with Langmuir and Schaefer. His brother, the famous writer Kurt Vonnegut, also worked at GE as a publicist.

Following Schaefer's cold box discovery, Langmuir asked Vonnegut to do quantitative work “on the number of ice crystals produced by dry ice.” This led Vonnegut to search for other agents that might initiate ice phase processes in a cloud. As he told the story five years later, “It occurred to me that if I could get something that was awfully close to ice in its crystal structure that might do the job, and I looked up in the handbook to find out what substances were close. I
came across ... lead iodide, antimony, and silver iodide.”
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Powdered lead iodide produced “a reasonable number of crystals” in Schaefer's cold box, a phenomenon that Schaefer attributed to the hexagonal shape of the molecules, but still they could not get a good result: “Well, I couldn't figure this out; so I was just puttering around and I decided to see just what happened when I put metal smoke in there [from silver]. I was amazed—the ice box was just swimming with ice crystals—colossal numbers.... Then I remembered silver iodide and made smoke.... Vaporizing silver iodide worked like a charm.” Vonnegut's laboratory notebook indicates that he had identified lead iodide as an artificial nucleating agent by November 6, 1946. After numerous trials, he finally got iodine vapor and metallic silver to work on November 14: “Hallelujah! the nucleation was even more wonderful.” By November 18, just four days after Schaefer's outdoor experiment, Vonnegut had found out that it was the silver iodide that did the job. Because of its hexagonal structure, silver iodide imitates ice condensation nuclei, causing “explosive ice growth” in supercooled clouds.
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Vonnegut soon started seeding experiments with ground-based silver iodide generators, but found it hard to tell where the smoke was going and what effect it was having. He did some inconclusive aircraft tests in December 1947, but “felt” that the experiments he conducted with GE meteorologist Ray Falconer with a silver iodide generator on the summit of Mount Washington were the most satisfying : “I feel darn sure we got some nice results ... we caused quite a nice snow squall downwind from the generator on air as it goes up over the mountain.”
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He had yet to develop reliable techniques for following the particles and measuring their concentrations. The General Electric News Bureau, however, was quick to claim credit:

Vonnegut, who was less sanguine, pointed out that silver iodide has its own problems. It is persistent in the environment and can activate long after its release in clouds of proper temperature; dry ice, though, works immediately and then sublimates. He recalled in an interview, “This is bad, I think, for commercial cloud-seeding operations, because I think they're playing with fire releasing this stuff all over the place and I think it's a shame they haven't shown any sense of
public responsibility particularly when they deny it has any large scale effect ... to stink up the atmosphere for hundreds or thousands of miles down wind producing God knows what effect is a dangerous thing.”
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Nevertheless, Langmuir touted chemical seeding agents as being superior to natural ice nuclei because they act at higher temperatures, they do not melt or evaporate, and they can be spewed into the atmosphere over widespread areas to remain active until it snows. He echoed the GE News Bureau in making unsubstantiated claims that the chemical might eliminate severe aircraft icing, suppress hailstorms, and perhaps, since by his estimates only 200 pounds of silver iodide would be needed to seed the entire atmosphere of the United States, could result in large-scale weather or even climatic changes.
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Project Cirrus was operating in Socorro, New Mexico, in July 1949, with Vonnegut running a test burner on the ground while the military air crews, with Langmuir and Schaefer as observers, seeded clouds aloft with dry ice. One day, one of Vonnegut's cumulus clouds “really whooped it up, and the first thing I knew there was lightning, and it was all very exciting, and I thought, ‘Gee, I wonder if I'm responsible for it.'”
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When his colleagues returned that evening with no results to report, Vonnegut ventured the suggestion that perhaps his ground generators had glaciated all the clouds, so the dry ice seeding planes could not find any for their experiments.

Noting that widespread rains were reported downwind on this day, Langmuir ordered seeding to be done periodically, once a week for eighty-two weeks, from December 1949 to July 1951. Then, even before the data were collected and other possibilities explored, he proceeded to make the outrageous claim that large-scale seven-day periodicities in the nation's weather were being caused by Vonnegut's single ground-based silver iodide generator located in New Mexico. Langmuir supported his claim by noting that the Midwest and East were moister than normal during this period, while the Southwest was drier than normal—conditions that occur naturally on a regular basis, although he did have to admit, sheepishly, that in the weeks when the generators were not operating, “rains were about forty percent greater than the other weeks.”
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Nevertheless, Langmuir went so far as to claim that severe flooding in the Midwest and the Ohio Valley, accompanied by widespread property damage and loss of life, was the result of these experiments. He apparently “proved” his result using unconventional statistical methods of his own devising.

In his insightful autobiographical memoir, Sverre Petterssen, a leader in the field of weather analysis and forecasting, reviewed his involvement with Langmuir in the 1950s. Petterssen was trained in the Bergen School of meteorology, chaired the Department of Meteorology at MIT, and served in Norwegian uniform in World War II, preparing forecasts for bombing raids by the British Royal Air Force, the Anzio landing, and, notably, the D-day invasion of Normandy. After World War II, Petterssen served as head of the Norwegian Forecasting Service, scientific director for the U.S. Air Force Weather Service, and professor and chair of the Department of Meteorology (later Geophysics) at the University of Chicago. He explained the situation:

Langmuir was unable to accept the criticism of Petterssen or the analysis of weather bureau statistician Glenn Brier that the atmosphere frequently exhibits a
natural
seven-day periodicity.
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After the New Mexico incident, Suits again warned Langmuir that his field experiments and unsupported claims might put Project Cirrus at risk and expose the lab to litigation. He pointed out that Schaefer and Vonnegut were “a great deal less certain” about the interpretation of the New Mexico results than he was, and that ground-based seeding would again raise legal questions for General Electric: “If the [cloud seeding] program develops in such a direction as to subject the Company to serious hazards from a liability standpoint, it may very well become impossible for us to continue with this work.” In a long letter to Langmuir, with carbon copies to Schaefer and Vonnegut, Suits reminded the team that “there has been no recent change in the law which makes it less necessary at present for General Electric personnel to be cognizant of the hazards from the standpoint of legal liability than when the agreement referred to above was reached.” Suits again reminded the team that GE employees were to serve only as advisers to the government: “GE personnel
must not
engage directly or indirectly in seeding experiments which might lead to harmful weather phenomena. They
may
engage in laboratory experiments which they consider advisable and in very small scale weather experiments for confirming laboratory tests with actual meteorological conditions.” Suits could not approve their publications that reported the results of large-scale modification. He issued a similar embargo on technical talks, claiming that GE was doing the experiments for the sake of humankind and was earning no profits from the activity: “I do not believe that our obligation extends to the taking of exceptional risks of damage suits as a result of any work which we may do in this field.”
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