Modifying the weather

Minot DN
Posted: 2008-01-07 11:40:22

Weather modification activities have been going on in North Dakota more than 50 years, but an element of the population remains skeptical about the benefits of altering an approaching storm.

Six counties in the state currently have weather modification, or cloud seeding programs, and all six are planning to implement the program in 2008, according to Weather Modification Inc., the agency that contracts with Bowman, Slope, McKenzie, Williams, Mountrail and Ward counties.

Hans Ahlness is the vice president of operations for Weather Modification. He said it’s often hard to convince skeptics that weather modification is providing a benefit even though it’s costing more in local taxes.

He said people will sometimes ask him to prove their individual farm received more rain than it did the year before because of cloud seeding. Ahlness said the system can’t be dissected in such a way to provide information that specific.

“It’s an operational program and there’s no research being done here,” Ahlness said. “It’s supported by taxes and in farming areas, people aren’t convinced it’s doing any good and they’re still paying taxes.”

Last year, the participating counties provided two-thirds of the funding while the state chipped in one-third, according to Weather Modification’s final operations report for 2007.

Darin Langerud is the director of the North Dakota Atmospheric Resource Board in Bismarck. He said weather modification is more about reducing hail damage than it is increasing rainfall.

“Though western North Dakota is a semi-arid climate, we get the sense from the county sponsors that hail suppression is their primary concern, followed closely by rainfall enhancement,” Langerud said. “I don’t doubt there are different opinions on which of the two goals is more important, but operationally, both go hand-in-hand. There is no dramatic difference in how each is accomplished as far as seeding operations go.”

Both hail suppression and rain enhancement utilize silver iodide as the primary catalyst. These microscopic particles are either disbursed in the updrafts directly below the base of developing cumulus clouds, according to Langerud, or are deposited directly into clouds through aircraft penetration.

“Either way, the primary goal of the silver iodide, or dry ice pellets, which is another method used, is to encourage development of precipitation, in this case, ice crystals, in clouds earlier than would occur naturally,” he said. “This makes more efficient use of the water in the seeded cloud to produce rainfall and it leaves less for making hailstones.”

According to Ahlness, one thing the general public doesn’t realize is that pilots aren’t creating clouds full of precipitation. They’re only modifying the potential that already exists.

He said since weather generally moves west to east in North Dakota, radar and maps are studied to determine the best approach to the storm and the safest approach for the pilots.

Ahlness added the program has improved dramatically since those experimental days of cloud seeding in 1951 and since Weather Modification began operations in 1961.

That, in turn, helps producers with planting and crop insurance decisions.

“There’s better coverage and better methods,” he said. “That’s a risk management tool.”

According to Langerud, long-term studies have shown that rainfall has increased approximately 10 percent, while crop-hail damage has been reduced dramatically, by 45 percent.

“Another study found that wheat yields in the “seeded” areas were approximately 5.9 percent higher, on average, versus adjacent areas where no (cloud) seeding was done,” he said. “Economic studies done by North Dakota State University have found the program’s overall benefit-to-cost ratio is around 35 to 1.”

According to Ahlness, there will always be people who consider cloud seeding to be witchcraft. To dispell that branding, Ahlness said Weather Modification is the largest agency of its kind in the world and is known around the world for the work it does in several countries.

The company’s Web site lists projects in North Dakota, Idaho, Utah, Nevada, Alberta, Morocco, Argentina, Greece, the United Arab Emerites and Indonesia. He said the company got its start in Bowman in the early ‘60s and moved to Fargo in 1993.

The current, six-county target area in North Dakota covers 10,321 square miles, some 6.6 million acres, or nearly 15 percent of the state’s area.

Weather Modification operated in 2007 in the state with eight aircraft, 10 pilots, nine intern pilots and five meteorologists.

Langerud and Ahlness both agree that five counties are fairly solid in their commitment to weather modification as those county boards understand the economic benefit.

But in Slope County, there are only seven of 34 townships (those along the Bowman County line) that contract with WMI. Ahlness said most of the rest of the county is in grazing land and those producers don’t want to pay an additional tax to receive the service.

The program has been up and down over the years and in the mid-1970s, there were 17 counties participating in the program. Benson, Nelson and Griggs counties were the most recent to bow out in 1981 and Williams has become the most recent add-on county.

Ahlness said it’s possible that producers farming large amounts of cropland may buy into the program without public funds, but it’s unlikely since localized areas can’t be targeted as well as entire counties.

But, he added, the seven townships in Slope County that are participating are evidence that smaller areas of property can be targeted.

New counties may also join the weather modification program if they feel they need reduced hail or increased rainfall, according to Ahlness. But it’s a bit more complicated than picking up the telephone and calling.

“The county has to want to get it going, take the initiative and set up the authority to get it going,” Ahlness said. “Somebody has to take a leadership role and get it going.”