Boston — PROJECT Stormfury, an effort to try to tame hurricanes, was born in 1962 as a joint United States Navy-Weather Bureau effort. Six major hurricane landfalls in two years (1954/55) caused more than $6 billion in damage (in 1983 dollars) and killed nearly 400 people. This prompted Congress to establish the National Hurricane Research Project -- now the Hurricane Research Division of NOAA's Atlantic Oceanographic and Meteorological Laboratory in Miami. Part of the program's mission was to look for ways to modify hurricanes.
Project Stormfury scientists thought they had a plan, based on the observation that the tighter the eye-wall circle, the stronger a storm's maximum winds. Stormfury theorists reasoned that, if the eye wall could be moved farther from the storm center, the maximum winds would slow. They believed the eye wall to be unstable. They also thought its clouds held an abundance of supercooled water -- droplets cooled well below their nominal freezing point. Seeding such clouds with silver iodide should induce th e droplets to freeze, releasing their latent heat. This heating should disturb the eye wall, which would then migrate outward. Experimental seeding of Hurricane Esther in September 1961 had seemed to indicate just such an effect.
Stormfury went on to seed hurricanes Beulah (1963), Debbie (1969), and Ginger (1971). Beulah and Debbie behaved as expected; maximum wind speeds slowed and moved farther from the storm center. Seeding had no effect on Ginger. But then the storm was judged to have been a poor candidate for seeding, anyway, because it lacked a well-defined eye.
Seeding ceased after Ginger. Candidate storms were hard to find. The Navy withdrew its support. And efforts to work in the Pacific Ocean, where candidate storms are two to three times more abundant than in the Atlantic, were vetoed by Pacific Basin countries whose permission was considered a diplomatic necessity.
Nevertheless, Stormfury had achieved some apparent successes that begged for further investigation. As such study progressed with more powerful aircraft-based instruments, the illusion of success evaporated. Observations of Hurricanes Anita (1977), David and Frederick (1979), and Allen (1980) showed natural eye wall migrations similar to those attributed to seeding in Stormfury tests. This strengthened the doubts some scientists held about the presumed cause-effect correlation between seeding and eyewal l migration. Also, direct sampling of clouds revealed a lack of the supercooled droplets essential for seeding to work.
Stormfury ended two years ago with the realization that it is futile to try to control hurricanes at this time. Summarizing the two-decade effort in last May's Bulletin of the American Meteorological Society, Hugh E. Willoughby and coworkers at the Hurricane Research Division noted, ``The goal of human control of hurricanes was captivating and seemed to be physically attainable in the beginning.'' They added, however, ``seeding in hurricanes would be ineffective because they contain too little supercool ed water and too much natural ice. Moreover, the expected results of seeding are often indistinguishable from naturally occurring intensity changes.''