Buoys Act as the Arctic's Diary

Contra-Costa Times
Posted June 4, 2003

By Alexandra Witze
ICE CAMP BORNEO, 89 DEGREES NORTH - Some oceanographers take monthlong research cruises in tropical waters. Far fewer go where temperatures plunge below minus 20 degrees, even as spring arrives.

But only here, at the top of the world, can scientists really understand what is happening at the Earth's poles.

Late last month, University of Washington-led researchers journeyed to the center of the Arctic ice pack, just 60 miles from the North Pole.

Here they scurried across the sea ice, stabbing holes to take water samples and plant scientific buoys.

If all goes well, the buoys will drift with the ice pack for the next year, serving as remote scientific sentinels as they radio back information about ocean conditions.

The data -- about the ocean's temperature, saltiness and other factors -- offer a key glimpse into major changes that are occurring in the ocean beneath the North Pole.

"The big picture with the Arctic is that things are warming up, and the ice is getting thinner and melting," says Jim Overland, an oceanographer at the National Oceanographic and Atmospheric Administration's Pacific Marine Environmental Laboratory in Seattle.

"The whole idea of the drifting station is that we build up enough years of data that we can see the changes and how they occur."

Without such information, scientists cannot understand how climate change affects the Arctic.

But it is a lot of work to install a few buoys that will not last more than a year.

First, the scientists must carefully weigh and pack each piece so it survives a rough airplane landing near a floating ice camp named Borneo.

Then they must find the perfect spot to deploy the buoys -- preferably a nice, flat chunk of ice surrounded by a well-developed system of pressure ridges that will accommodate the grinding forces that shear apart the ice pack.

And, of course, the scientists must always carry a rifle in case they run into a polar bear.

The research is worth it, they say. This spring's work marked the fourth consecutive year of a five-year program, the North Pole Environmental Observatory, that's meant to monitor oceanographic changes in the center of the Arctic.

Every bit of data is priceless when so little is known about the region, says Tim Stanton, an oceanographer at the Naval Postgraduate School in Monterey.

"One buoy buys you much more than zero buoys," he says.

• • •

Until the late 1990s, U.S. scientists had another great source of data -- oceanographic information gathered by nuclear submarines that crossed beneath the ice cap.

But those submarines are no longer running, and now scientists are looking for another way to make long-term measurements in the center of the Arctic.

The North Pole Environmental Observatory is one such attempt. For the first time, scientists have been able to consistently observe in the center of the Arctic, says Jamie Morison of the University of Washington, the project's leader.

The observatory combines buoys with a deep-sea cable, laden with instruments and a collection of water samples taken over hundreds of miles.

The goal: to understand the dramatic changes the Arctic Ocean has undergone during the past decade, says Morison.

During that time, atmospheric pressure has substantially dropped over the central Arctic, causing the ocean to circulate more in a counterclockwise direction than its usual clockwise path.

That change causes the ice cover to spread out more, opening up more water. Heat from the sun can then melt ice more rapidly, kicking off a cyclical effect that is hard to stop, says Morison.

• • •

At the same time, Arctic ice is under attack from below. A warm layer of water from the Atlantic Ocean is pushing ever farther into the Arctic, thinning or even destroying a cold, salty layer that acts as insulation for the ice.

Without the cold layer, the ice can melt much more rapidly than before, Morison says.

"That's one of the real signals of change in the Arctic," he says.

How that heat moves through the upper layers of the ocean is the focus of the buoy designed by Stanton.

As installed near Camp Borneo in late April, the buoy rests on the ice, its dome-shaped top keeping snow from accumulating. Beneath it stretches a 16-foot pole, laden with instruments to measure heat, saltiness and momentum created by the movement of the ice pack.

From these factors, Stanton can calculate the heat flux within the ocean -- a quantity that has not been well-measured until now, he says.

"It sounds like minutiae, but to get that stuff right is very important," he says.

The more rapidly water mixes at different depths, the more dramatically heat can flow between the various layers.

And measuring that can help oceanographers better understand how the incursion of warm Atlantic water might affect the cold Arctic Ocean, Stanton says.

If all goes well, the buoy will remain on the same piece of ice for the next year, radioing back measurements to Stanton's laboratory.

Eventually, the floe on which it rests should drift past Greenland, through the Fram Strait, and into the North Atlantic where it will melt and drop the buoy.

But that doesn't bother Stanton as he kneels to adjust the solar panels on his creation.

"It's just a big laboratory for a turbulence geek like me," he says.

• • •

Nearby, oceanographer Sigrid Salo of the Pacific Marine Environmental Laboratory has installed a number of other buoys.

One is a weather station, measuring temperature along a 9-foot-high mast. Two are Webcams, scheduled to broadcast live pictures of the North Pole at www.arctic.noaa.gov.

Two are thermometers that plunge through the ice, measuring how thick the ice grows in winter and how thin it gets in summer. And two are radiometers, small devices that sit on the ice and measure radiation from the sun.

Nobody has ever left radiometers like these unattended on the ice before, says Salo, because frost usually covers them and renders them useless.

But her team designed a set of small heaters and fans, powered by eight 75-watt solar panels, that will constantly blow warm air over the translucent bubbles that receive the sun's radiation.

The heat should keep the devices clear enough of frost to continue working at least until winter, she says.

But neither she nor Stanton has been able to avoid the main problem of buoys -- the danger of their being crushed or sheared apart in the ever-shifting motions of the Arctic ice pack.

In the observatory's second year, several of the buoys were destroyed soon after being installed near the pole.

"You can put the best-made buoy out there and the ice will just crunch it," says Salo.

The fanciest of this year's buoys belongs to a team from the Japan Marine Science and Technology Center in Yokosuka City.

Takashi Kikuchi and Hirokatsu Uno installed a superbuoy that measures temperature and salinity at several depths down to nearly 1,000 feet. It also measures ocean current, atmospheric temperature and pressure, and wind velocity.

The Japanese team took a long helicopter flight from the Borneo camp to reach a site on the other side of the Lomonosov Ridge, an underwater mountain range that runs close to the North Pole.

By setting the buoy on the Pacific side of the ridge, they hope to measure how the ocean currents are deflected by it.

All the buoys are now part of the International Arctic Buoy Program, a network of drifting buoys that has been in place since 1979.

The new research, says Morison, is more than just an adventure trip to the North Pole.

"It really fills a hole in the center of the ocean," he says.

Contra-Costa Times

- Back to News Home -