radar advances as ice retreats

''Two summers ago, we lost a glacier in the Atlin region - a whole mountain glacier was gone," says Stephen Mooney, director of Cold Climate Innovation at the Yukon Research Centre at Yukon College.

by Erling Friis-Baastad

‘‘Two summers ago, we lost a glacier in the Atlin region – a whole mountain glacier was gone,” says Stephen Mooney, director of Cold Climate Innovation at the Yukon Research Centre at Yukon College.

“It was a reality check,” he adds, pointing to the significance of losing a long-time feature and water source in the headwaters of the Yukon River.

“We found out last year that 16 per cent of the water in the Yukon River was from glaciers – so if glaciers start leaving us, it could have an effect on the Yukon River and hydro generation,” says Mooney.

Such an ice disappearance is no anomaly. Roughly “90 to 95 per cent of glaciers in the Northern Hemisphere are in retreat, and most of them have been since the late 1800s,” says Mooney’s colleague, University of Alberta glaciologist Jeffrey Kavanaugh. What we’re seeing, Kavanaugh explains, are changes to climatic regimes, which in turn affect water sources that power cities, make agriculture possible and provide transportation routes.

“But change is one of the few constants in the world,” says Kavanaugh. People may argue about the cause – or causes – of record-breaking heat waves, ice-field disappearances and freak mega-storms, but for now it would be a better use of our energy and skills to monitor those changes and research potential consequences, he says.

That’s exactly what Mooney, Kavanaugh and other scientists and engineers associated with the Cold Climate Innovation Centre and Northern Climate Exchange are doing, with the help of dual frequency ice-penetrating radar. It’s a Yukon research project funded by the college with money from the Yukon government’s Department of Economic Development, using Yukon-built technology that’s being tested in the territory itself.

Not only will the radar help us understand, and work to cope with, changes to our hydrological health, but the efficient new technology could benefit jurisdictions throughout a thirsty planet now waking up to climatic changes and threats to essential water sources. Whitehorse residents are not alone in their worries about the health of a river.

Ice-penetrating radar has been around, in more basic forms, since the 1960s, says Laurent Mingo, an engineer who specializes in data acquisition systems. Mingo’s Vancouver company, Blue System Integration Ltd., is working closely with Yukon’s Icefield Tools Corp. to perfect a portable ice-penetrating radar system whose transmitting component is made in the territory.

With the transmitter, radar waves are pulsed down into the glacier. These bounce back to reveal the glacier’s bed and depth. Eventually, the entire glacier’s volume and shape can be reconstructed. This is essential for modeling ice masses, their balance and their flow dynamics, says Mingo. But the process was originally slower and more expensive, as it could only use a single frequency at a time.

The dual-frequency radar equipment consists of a transmitter and receiver on a ski-mounted platform, dragging a 10-metre tail-like antenna. Because the system, pulled across the ice by researchers, works on two frequencies simultaneously, it can reveal internal glacier characteristics that would require several passes, or transects, to reveal if working at a single frequency.

With critical support from the Kluane Lake Research Station last spring, a team conducted a successful test of the system on a 10-square-kilometre valley glacier in the Donjek Range. Even severe weather challenges helped prove the new technology’s worth, says Mingo. Researchers encountered blizzards, which made moving around on the glacier difficult. “We had to wait for visibility and reasonable travelling conditions. We were hoping we’d have five to seven days of actual survey time,” he says. The team only got three, but working with two frequencies at once helped speed the work up to fit within the truncated time frame.

Asked if he “invented” the dual system, Mingo says, “It would be an overstatement to call it an invention. It is rather the result of a continuum of improvements made at many technological levels, such as electronics miniaturization, a computing platform of reduced size and power, and especially software.”

And the improvements are definitely ongoing. Mingo says he will be devoting much of this winter to expanding the radar’s frequency range and, consequently, its ability to probe different strata of ice.

With the right technology, researchers could employ frequencies “anywhere from the megahertz range to the low gigahertz range,” says Mingo. “We’ve been working with frequencies from 5 to 70 megahertz,” he adds, “but working at much higher frequencies will require new hardware.”

He likens this to transportation technology: “A pickup truck may be fine for basic hauling on back roads, but doing high-speed racing, for instance, would require a much different vehicle.”

Our society, which hasn’t been around all that long geologically or even biologically speaking, has been built around the rather stable climate “that we’ve been enjoying,” says Kavanaugh. And we have often taken for granted balanced systems that make our way of life comfortable, and even possible.

Consider the basics of how alpine glaciers work. Snow falls in higher elevations and the major part of that snow remains more than a year. “As more snow is piled on top, it is compacted as ice,” says Kavanaugh. That ice further compacts under its own weight and moves slowly downhill into a warmer elevation.

“In a stable climate a glacier will come to an equilibrium where the amount of water that melts each summer balances the water input each winter,” he says.

In an unstable climate – well, we’re in the process of discovering the effects. “The biggest and most direct impact and the one that is most likely to finally inspire people to take this seriously and adjust to it will be the economic impact,” says Kavanaugh.

The mandate of the Cold Climate Innovation Centre “is to stimulate economic development through cold climate innovation technology,” says project manager Mooney. In helping develop a device that allows people to monitor loss of ice and hydro health (the tipping of a balance in an ever-more power-hungry world) CCI is surely living up to its promise.

This column is co-ordinated by the Yukon Research Centre (YRC) at Yukon College with major financial support from Environment Yukon and YRC. The articles are archived at http://yukoncollege.yk.ca/research/publications/newslatters_articles

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