Polar energy

Two biologists walk from the icebreaker Des Groseilliers toward their lab. Scientists work in more than a dozen huts and tents on the ice. Following carefully laid plans, the icebreaker was frozen into place in the Arctic Ocean, and left there for a year.

  Floating frozen data factory
Our first reaction was that it didn't sound like history's most brilliant plan: deliberately freezing a good, working ship into the Arctic ice pack, it's not the titanicand then leaving it for a year to drift with the slow-moving polar ice cap.

But last October a big group of polar researchers left the ship in an icy embrace a few hundred kilometers from the North Pole anyway. They think it's such a great idea that they are actually seeking publicity for the project they call SHEBA, for the Surface Heat Budget of the Arctic Ocean. The project is the National Science Foundation's largest-ever Arctic science program.

Braving eternal darkness, frozen fingers and the occasional polar bear, these researchers are tending a zoo of scientific instruments in the Arctic Ocean. Their base is the icebreaker Des Groseilliers, a Canadian ship that has been part of the polar icecap since last fall.

14 OCT 1998. The Canadian icebreaker Des Groseilliers has left the ice floe it's called home for more than a year and is expected in Prudhoe Bay, Alaska, later this , concluding the field work phase of a monumental study of the Arctic environment. "We've observed the ice, the atmosphere and the ocean over a full annual cycle covering the physical variables in all three systems. We've seen it all: melting, freezing, heating, cooling, ridges, cracks, leads, melt ponds and all kinds of different formations of ice and snow," said Richard Moritz, polar scientist with the University of Washington's Applied Physics Laboratory and director of the SHEBA project office.


One major houseboat
The ship serves as the floating base for an elaborate, expensive effort to find out how heat moves between air, water and ice. When it's done, SHEBA's dozens of scientific projects should fill in a blind spot in computer models that predict climate change. These models predict that accumulating greenhouse gases will warm the globe by an average of between 2 and 6 degrees Fahrenheit over the next century. (The Why Files covered the tools of the global warming debate.)

These computer models are the best way to predict how greenhouse gases could affect climate, but they have problems. For example, there's little information about how heat leaves the Earth at the poles. This is important because Earth's atmosphere and oceans act as a big heat engine. The power comes from sunlight, which primarily warms the tropics. Much of this heat energy is moved through the oceans and atmosphere toward the poles where it radiates back to space. So to know how much heat will remain on Earth as greenhouse gas concentrations increase, you have to know how it moves around. And that takes data.

Researchers regularly brush ice crystals from instruments on this 20-meter tower on the ice near their ship. These instruments measure temperature, relative humidity and wind speed and direction.
Photos: University of Washington.

stand back It's easy enough to set up a monitoring station in the tropics -- it's one part meteorology, and one part Mexican margarita. But the poles are a different story -- a story that SHEBA is trying to fill in. In the Arctic Ocean, an ice-covered region larger than the United States, temperatures reach 60 degrees below zero (Fahrenheit), the sun is absent for months at a time, and we don't even want to think about the wind chill.

Suffice it to say that researchers get cold and dumb. They call the syndrome Dreaded Arctic Brain Fuzz, and you don't want that when you encounter ice coating a precious instrument or when a hungry polar bear encounters you.

Headin' west: the iceboat started at the blue spot last October and has gradually drifted west. It's now 450 miles north of Barrow, Alaska. Courtesy of SHEBA.
All these obstacles are just in another day's work for SHEBA's researchers. (Or at least, for the over-winter crew. Most of the scientists abandoned ship soon after they set up their equipment last fall and they now monitor proceedings from the comfort of their university laboratories. A group of about a dozen technicians had the fun of tending the instruments through the Arctic winter.)

That's MY parking spot!
The Des Groseilliers was put in place last October, when it followed a larger icebreaker that smashed through the ice pack to a parking place in an ice floe 300 miles north of Barrow, Alaska. As the temperature fell, the Des Groseilliers froze into place. The ship's rounded hull is supposed to slip out of an icy embrace that would crush an ordinary ship.

The site was chosen for easy -- relatively speaking -- access from airfields in Alaska, and because the ice is not expected to grow too thick to extricate the ship. "We didn't want it to get so frozen in place that we couldn't get it out," says Michael Ledbetter, director of NSF's arctic system science program. In late March, 1998, Ledbetter says the ice is about 2.8 meters thick around the ship.

slip sliding awayHe says that's not enough to worry about, but the Canadian Coast Guard, proud owner of the Des Groseilliers, doesn't want to take any chances with its ship. "The original idea was to steam out on its own power," says Ledbetter. But the Coast Guard wants to play it safe, so it will send in the bigger icebreaker for an extrication ceremony next October. Already, about half-way through the mission, the Des Groseilliers has drifted with the icecap about 400 miles west of its original parking spot, Ledbetter says.

The constantly shifting ice has caused its share of problems -- open water has developed quite near the ship, forcing the on-ice scientific camp to be moved. Although nobody has fallen through the ice, one snowmobile has -- it's presumed to be lying on the ocean floor, 11,000 feet below the ice.

So what about the science?
The mission has two kinds of objectives, says Ledbetter. First, to measure the sea-ice reflectance, which changes through the year, and second, to examine the role of clouds in reflecting heat back to the Earth.

In their quest, scientists are employing thermometers, wind gauges, humidity gauges and energy flow meters. The various instruments are mounted on the ice, on airplanes and on balloons. Occasionally, a U.S. Navy submarine will prowl beneath the ice to measure ice thickness. And satellites overhead will also spew out data on surface and atmospheric conditions. The goal is to get complete data on energy flow in a column of water, ice, and air extending from the mid-ocean depths to the stratosphere.

Ledbetter expects the project to produce a mountain of data. Since essentially none has been analyzed yet, the real benefits from the huge project are still to come as scientists warm their frost-bitten toes and get down to the serious analytical work. After four or five years, SHEBA's vast store of results should be playing a role in ever-more-accurate computer models for predicting the climate.

Exclusive: First photos of seals feeding under the Antarctic ice!

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