In light of these experiments, Stormfury faced the same troubling questions: Did eyewalls sometimes widen spontaneously, without human intervention? Meteorologists could not find enough suitable storms near Florida to examine, and in the early 1970s their work ground to a halt. When the scientists tried to revive the project a few years later, political forces worked against them. They tried to shift hurricane seeding to the Pacific Ocean, but China, Japan, and Australia said loud and clear the United States better back off.
Stormfury’s coup de grace came in the early 1980s, when Hugh Willoughby and two other alumni wrote a demoralizing scientific analysis. They concluded that hurricanes did form new eyewalls all the time—with or without seeding. They also showed that the amount of supercooled water in hurricanes—a necessary ingredient for seeding—was orders of magnitude smaller than scientists had assumed. All in all, then, seeding had probably not disrupted a single hurricane, and any observed decreases in wind speed were probably coincidental. In 1983, the Department of Commerce killed Project Stormfury for good.
Weather modification combines two ancient dreams of humankind—flying and controlling the weather—and the hope of joining the two has never quite died. Private companies still seed clouds to bring rain, and China famously seeded Beijing skies to ensure clear weather before the 2008 Olympics. Colorado meteorologist Bill Woodley, a Stormfury veteran running the Homeland Security study, believes computer simulations will bring a new era of sophistication. “The explosive development of numerical models and computers allows us to play God, essentially,” he says, and evaluate scenarios without expensive tests. “In a year or two, we hope to weed out those hypotheses that have real merit.”
Willoughby, however, questions the ability to generate rain that falls all the way to the ground: “Many very smart people spent tubs of money seeding clouds, but I know of no published example of an experiment where one investigator applied a given technique to achieve a statistically significant increase in precipitation and another applied the same technique in a different setting to get the same result.” He adds, “Since replication is the essence of science, one is tempted to say that it was all nonsense.”
Though most scientists remain skeptical about controlling weather, Projects Cirrus and Stormfury still made important contributions to the field of meteorology. The thousands of seeding runs helped scientists piece together how storms behave, work that has produced better forecasts and thus saved innumerable lives: Despite an exploding U.S. coastal population, the likelihood of dying from a hurricane now is 1/100th the likelihood in 1900.
Still, Irving Langmuir would be crushed to see the lowly state of weather modification today. However sophisticated it has grown since 1946, meteorology remains a passive, not active, science. Pilot David Turner remembers his own pangs on Project Stormfury’s demise. “We’d spent a lot of time, and there were a lot of airplanes involved,” he says. “It was disappointing to finally concede we couldn’t really do it. The storms were so big, and we were so small.”
Sam Kean is the author of The Disappearing Spoon (Little, Brown, 2010).