UB's "Ice Man" Takes Time From Classroom to Study Lake Freeze, Thaw Dates As Indicators of Climate Change

BUFFALO, N.Y. -- At the University at Buffalo, the "ice man" cometh with an ice auger, an ice spud, a meter stick and a couple of screwdrivers that hang from a string around his neck.

Kenton Stewart, Ph.D., professor of biological sciences in the UB College of Arts and Sciences, is UB's iceman. He teaches limnology, the science of bodies of fresh water. One of his research projects involves studying the freeze and thaw dates of lake ice as an indicator of global climate change.

In fact, he may have the largest scientific inventory of lake-ice dates in North America, covering more than 250 lakes in New York State alone and several hundred in other states.

His work has led him to develop skills in determining whether or not a lake's ice cover is safe to walk on; at UB, he has performed this sometimes risky service almost every winter for the past 20 years.

On a recent expedition to test the ice on Lake LaSalle on UB's North (Amherst) Campus, he strode quickly out onto the middle of the lake.

"I'm not worried about the ice on this part of the lake," he said, noting that just a few days before, he had measured 10 inches of cover on the lake.

Thirty paces out, Stewart decided to take his first measurement. He brushed the snow away from the lake's surface, then plunked down the ice auger and began drilling a hole into the frozen floor. He turned the handle, going deeper and deeper, then pulled it free. Just inches from his feet, a small spring of water gurgled to the surface.

Stewart stuck his meterstick down into the water: 29.5 centimeters -- or about 12 inches --of ice.

"This is twice as thick as the maximum amount of ice we had all last year," Stewart noted. Last year, he added, the lake was thick enough to walk on for only one week and there were 54 days of ice cover, the fewest number of days since 1975.

He pointed out that last year also was a strong El Nino year, a phenomenon that reflects differences in sea-surface pressure between the eastern and western Pacific Ocean. When those differences are especially pronounced, that spells an unusually mild winter for parts of North America.

This winter, on the other hand, is La Nina, the winter that follows El Nino, and is usually characterized by colder weather with more precipitation, which Buffalonians came to know all too well earlier this winter.

"El Nino events vary in their impact and do not affect all parts of the globe equally," he said. "The biggest unknown is what the effect is regionally."

To examine how different regions are impacted by El Nino, Stewart monitors more than 250 lakes throughout New York State and hundreds of others in other states, primarily Maine, Wisconsin and Minnesota.

"I do these long-term studies to see whether lake-ice dates can serve as proxy indicators for climate change," he said.

Strictly a grass-roots effort, the project began around 1970 when Stewart was looking at a few of the Finger Lakes in New York State. From there it escalated.

Stewart obtains data from a vast network of volunteers he has recruited who live near the lakes he monitors. Through phone calls or postcards, the observers let him know when their lakes freeze over in winter and break up in the spring.

According to Stewart, over the years, some of the lakes have begun to show one sign of global climate change: an earlier break-up of ice in the spring. He presented some of his results last summer at a meeting of the International Limnology Society in Dublin.

Stewart said his work sometimes is challenging.

When conditions on Lake LaSalle aren't good, for example, he makes sure to take along a life jacket and a toboggan, which he can pull up to the edge of the ice. That's also why he always carries screwdrivers, so he can "claw out" if he falls in. Luckily, he hasn't had an accident since he was a graduate student.

"It's strenuous work and can be a little nerve-wracking at times," he conceded. "But it's the most direct way to get this information. That's part of the lure of science."