On a morning in July it is clear and hot in Bismarck, North Dakota, and only slightly cooler in Bruce Boe’s office. The office, packed tight with computer data tapes, books, documents, and pamphlets about weather, sits in an old brick building separated by a parking lot and a green from the stark concrete tower that serves as the state’s capitol.
The buzz of an old air conditioner nearly drowns out normal conversation, but Boe, a strapping 6 foot 5 native of Montana dressed in jeans and cowboy boots, ignores the noise as he rushes through some paperwork. He’s trying to order a yellow chemical compound called silver iodide. Boe needs the substance, a salt, to accomplish a feat long promised by assorted hustlers, hucksters, and mystics, yet long viewed by skeptical scientists as impossible. Using this chemical, Boe says, he will make reluctant clouds rain. At the same time he will rob fierce hailstorms of their power
A cloud physicist and executive director of the North Dakota Atmospheric Resource Board, Boe heads one of the country’s longest-running programs to modify daily weather, a program in operation since 1961. Each summer, whenever angry storm clouds roll across western North Dakota, a small air force takes off from rural landing strips. When one of the planes reaches the base of a threatening thundercloud, the pilot flips a switch to release plumes of microscopic silver iodide particles. And when the particles meet cool moisture in the cloud, they--in theory--trigger the formation of welcome raindrops or tiny hailstones that fall from the sky before they have time to grow into large flying rocks of ice.
In this part of the country walnut-size hailstones are as destructive as a swarm of locusts. A hailstorm can turn a healthy wheat field into a useless mat of green pulp in less time than it takes a farmer to fill out a crop-insurance form.
The flying cloud seeders’ objective has been to break storms before such damage is done. But for most of the last 30 years, they couldn’t prove they were doing their job. One of the criticisms that’s always been leveled at modification people is, ‘You really don’t know what you’re doing,’ explains Boe, who has headed the seeding program since 1988. You go seed a cloud and it rains and the critics may say, ‘Well, you don’t know that you caused it. Maybe it was going to rain anyway.’ The problems went beyond proving cause and effect--sometimes the seeded clouds didn’t do anything.
