Rain, Rain, Go Away

A superabsorbent polymer reinvigorates an old dream

By Jennifer Kahn|Sunday, September 01, 2002
RELATED TAGS: GADGETS, NATURAL DISASTERS


A typical tropical storm, such as Hurricane Floyd, seen near Florida in 1999, carries energy equivalent to 10,000 one-megaton hydrogen bombs—a huge challenge for anyone out to control the weather.
Photograph courtesy of NOAA/GOES/NASA Goddard Space Flight Center.

One overcast day last July, a small industrial firm loaded a cargo plane with four tons of absorbent polymer powder and took off from the Florida coast heading east. The plane flew until it was over international waters and above a mile-long cloud formation. Skimming the surface of the formation, the pilot dumped the powder, which drifted into the mist below. Minutes later observers in radar stations saw the cloud evaporate and disappear. Far below, a misty gel rained down into the waves and dissolved. In a very small way, the Dyn-O-Mat company may have changed the weather that day.
    Like telepathy research and antiaging experiments, the dream of controlling the weather on a large scale has never quite disappeared. In 1957 a presidential advisory committee warned that weather modification "could become a more important weapon than the atom bomb." During the Vietnam War, the army mustered nearly 3,000 cloud-seeding missions, dropping silver iodide particles to swell monsoon rains over the Ho Chi Minh trail—all, apparently, to no avail. For the past two decades, researchers at the National Oceanic and Atmospheric Administration have tried to alter fronts and weaken hurricanes, also without success.
    But failure seems unlikely to vanquish hope when it comes to manipulating the weather. Last year, for example, a San Diego company proposed fighting tornadoes by beaming microwaves at them from space. About the same time, a hurricane researcher from the Massachusetts Institute of Technology advised that coating the oceans with a thin layer of oil might stop the evaporation that powers large storms.
    "So far, every experiment showing a statistically significant effect has been discredited," says Hugh Willoughby, a research meteorologist with the Hurricane Research Division of the National Oceanic and Atmospheric Administration. Still, he remains a self-proclaimed "enabler" of weather-modification enthusiasts. "I probably read too many sci-fi books growing up, but I love the idea," he says. "Imagine being able to herd clouds over cropland or stop hurricanes before they hit land."
    Of course, people alter the weather unintentionally all the time: Just by driving automobiles, they create smog that changes rainfall patterns. But focused tinkering is another matter. Weather systems are chaotic and incalculably complex. Turbulent winds, heated by the sun, bounce off mountains and collide with other systems, each of which has its own spiraling, tumbling momentum. Success itself runs the risk of triggering a chain reaction. Rains in a parched region of Africa, say, might trigger a drought in China. Furthermore, weather systems are so powerful, they can absorb almost anything humans throw at them.
    Undaunted, Dyn-O-Mat is forging ahead with a grand experiment—making an entire tropical storm disappear by dumping 300 tons of the company's patented powder into it. This month, if all goes to plan, two Russian planes will coat a five-mile-long wedge on the slow side of a tropical storm's eye. Dyn-O-Mat's president, J. D. Dutton, says the sudden evaporation should disrupt the storm's momentum, causing it to shear off and unravel.
    At Dyn-O-Mat's Riviera Beach offices, there is little evidence of such bold plans. The conference room is stacked with bilge balls and oil booms that evoke the company's main business, selling products to control petrochemical spills. But in the small lab here, a lush plant grows out of what looks like a tub of lumpy pink gelatin. This turns out to be Dyn-O-Moist, which helps lawns stay damp without frequent watering. The company also produces Dyn-O-Fire, a nonflammable gel that clings to leaves; Dyn-O-Drought, which stores morning dew for use by arid-land farmers; and other unusual products, including a sipping straw that changes color if a beverage passing through it has been spiked with Rohypnol, the date-rape drug.
    The star of the weather show is called Dyn-O-Storm. Grainy and white, it looks like powdered laundry detergent. It's made from the same cross-linked polyacrylic acids that fill diapers: long, netlike molecules that unfurl in the presence of water. When sodium ions are added to the formula, they neutralize the acids and form a superabsorbent web. Water molecules have a slightly positive charge at one end and a slightly negative charge at the other, so they normally clump together. But in the presence of Dyn-O-Storm, they separate and stick to the charged ions in the polymer's net. The magnitude of the effect is eerie. Scatter even a few grains of Dyn-O-Storm into a bowl of water and the water congeals instantly into something rubbery and gray. It can then be dissolved in seawater because sodium and calcium ions bond more strongly with the polymer, knocking the water molecules free.
    Chief executive officer and inventor Peter Cordani, a former golf course engineer, got the idea for Dyn-O-Storm three years ago when a small amount of another polymer touched his wet hands, which became instantly dry. Cordani spent the next week mixing together various off-the-shelf polymers. Early blends used round grains that ripped right through clouds like BBs. Cordani consulted Willoughby, who suggested making cereal-flake-shaped particles that would flutter down slowly, absorbing maximal water before exiting.
    These days Cordani is occupied by threats to the success of the impending test of Dyn-O-Storm on a tropical maelstrom. There is a chance that the storm's high winds might simply fling away the 300 tons of powder before it can be effective. Worse, the resulting gel-spew could blow back and smack the seeding airplanes. And the powder itself may pose a minor health risk. "I inhaled a bit by accident and had bronchitis for a week," Willoughby says. "The stuff turns to slime in your lungs."
    Even if Cordani succeeds, he may have trouble proving it. Most storms weaken naturally. Who will know if Dyn-O-Storm works or nature took its course? The same uncertainty haunts Dyn-O-Mat's original test, says Willoughby: "Sure the cloud disappeared, but thunderheads in Florida typically have a very short life. In 10 minutes, that cloud might have evaporated on its own." He was initially supportive of the results, but Willoughby has since distanced himself, calling the experiment "unconvincing."
    If Dyn-O-Storm doesn't prove effective, Cordani will simply move on to some 30 other products his company is developing. One of these—a tea bag filled with an oil-absorbent polymer, called Dyn-O-Trim—promises a different kind of miracle, one aimed at chefs and home cooks. "It takes the fat out of soups and gravies," Cordani says. That sort of wizardry should not be surprising from a company whose CEO likes to say "The sky's the limit."





The National Climatic Data Center's Worldwide Weather and Climate Events site offers a complete record of notable weather disasters: lwf.ncdc.noaa.gov/oa/reports/weather-events.html.


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