Computer simulations of the forces at work in the most violent storms have shown that even small changes in cloud temperature can affect their paths – enabling them to be diverted from major cities.
IN THEORY, THE IDEA IS simple: Lower the temperature of the clouds, and scientists could weaken a hurricane or even alter its path. In one scenario, airplanes would spread a layer of soot into the icy clouds at the top of a storm system, cooling them further and slowing the winds. Cut those wind speeds even a little, scientists say, and the devastating power of a storm surge could be drastically cut, perhaps saving lives and property.
Hurricane Katrina has sparked renewed interest in weather and atmospheric modification, a discipline that has been around for more than a half century and is used to stop hail in North Dakota and western Canada and to change rain patterns in many countries. China plans to use weather modification to keep rain away from the Olympics this summer.
Now, the Department of Homeland Security’s Science and Technology Directorate, which helps agencies from the Federal Emergency Management Agency to Immigration and Customs Enforcement, is expressing an interest in the science of hurricane modification. “It sounds kind of crazy and science fiction-ish, but it’s really the direction we need to go in,” Chris Doyle, head of DHS’s science and technology research division, told a conference of the American Meteorological Society last month.
Enter hurricane researcher Joseph Golden, a veteran of Project Stormfury, the federal government’s last foray into weather modification, which began in the 1960s. Golden organized a meeting of scientists at the conference to discuss weather modification and was surprised to find the topic far less controversial than during the Stormfury days. “I expected a far more contentious discussion,” he says. “But there are still major issues that were never resolved, like what about the unintended consequences.” Where, for instance, would scientists direct a storm? Toward a less populated area? What about the impact on other nations? Mexico, for instance, relies on hurricanes for a significant portion of its annual rainfall. And who would be accountable if something went wrong?
While it failed to knock out hurricanes as intended, the original Project Stormfury, run through the National Oceanic and Atmospheric Administration, did contribute much to scientists’ understanding of major storms, particularly about how their structures change. The project also tried “seeding clouds,” particularly with silver oxide crystals, to super-cool the clouds and, hopefully, weaken hurricanes. Tests on several Atlantic hurricanes revealed that the structure of the storms was not what the team had theorized and that small-scale cloud seeding was ineffective.
Now, with far more sophisticated computer modeling and more advanced aircraft, weakening storms seems closer, if researchers can only get funding to test their theories. Several million dollars in seed money from DHS could fund some studies, according to scientists on the AMS panel. Workable tests could be far more expensive.