Eyes upon the global ice Navigational needs: From a modest building in Prince George's County, hard data about cold waters keep mariners from finding themselves on the rocks.

February 15, 1996|By Will Englund | Will Englund,SUN STAFF

SUITLAND -- A collection of overheated little windowless offices here may be the best place in the world for getting a grasp on just how much of the globe is really, truly, icily cold.

Here in Prince George's County, in a bland federal of fice building across the street from a carpet store and a strip of fast-food joints, is the nerve center of the ice-bound world -- or at least the navigable part of it. From the Bering Strait to the Weddell Sea, from the Gulf of Bothnia to Baffin Bay, from Sault Ste. Marie to Havre de Grace, if it's iced up, the people here know about it.

And their job is to pass on what they learn to mariners throughout the colder parts of the world.

This is the National Ice Center. Passersby often assume it's some acronymic agency: the Interagency Committee on the Economy, perhaps, or the Intelligence Coordinating Entity. Hard to believe, but it's just plain old I-C-E -- the stuff that, if you're not careful, can seize a ship in no time and delay it, dent it or dispatch it to the bottom.

There are different ways of looking at ice: From a satellite, by radar, from the deck of a ship, from the cockpit of a plane.

Analysts at the National Ice Center, jointly run by the Navy, the Coast Guard and the National Oceanic and Atmospheric Administration, use them all -- or, at least, they use whatever sources of information are available for any particular part of the world. They sift the evidence and plot ice charts for any mariner who wants them -- thrice weekly for the Great Lakes, weekly for the Arctic and Antarctic -- as well as periodic forecasts and other special bulletins.

To put the incoming pieces of information together into a useful chart, said Lt. Cmdr. Steven J. Rutherford, "requires a little bit of art and a lot of experience."

And they're not just worrying about where the ice is, but how thick it is, what kind it is, and how old it is. All of these factors affect the strength of the ice, and thus a ship's ability to smash through it. Seriously, are we looking at frazil, shuga, nilas, brash, ice breccia, pancake, hummocked or maybe sastrugi? Is that a small floe or a bergy bit? Is that a flaw polynya, or only a blind lead?

Multiple sources

But as the raw information flows into Suitland, no single source can give a complete picture. Bad weather and inaccessibility are constant problems.

Satellite imagery provides a satisfying overview of the world's ice sheets, but it's lacking in what the people here call "ground truth." You want ground truth? You send a Navy aerographer's mate out in a plane and fly it at 500 feet over the ice edge. That gives you a feel for what you've got that you just can't get from out in space somewhere.

There are six men in the ground truth squad, out of 80 total staffers at the center. They spend most of the winters rotating in and out of Traverse City, Mich., where the center's reconnaissance planes are based. From there, they follow the ups and downs of ice throughout the Great Lakes.

In the spring and summer, when the temperatures in Suitland reach into the 90s, they send periodic expeditions to bases in Greenland and Labrador from which to monitor the Arctic. But the Arctic is so vast that aerial reconnaissance can do little more than provide a sampling.

Last week Ed Cobb, a chief petty officer, did a reconnaissance flight over the upper Chesapeake, at the Coast Guard's request. He found rotten, puddled and flooded floes and no threat of ice jams -- all in all, pretty ho-hum.

Out in Michigan, on the other hand, where it had been 20 below the week before -- that was something. There had been open water, but it didn't last long in those conditions.

"When the wind died down you could practically watch it freeze," he said.

Open water on the Great Lakes in the depth of winter is not the usual order of business. But last summer was so hot that the lakes stored up more heat than usual and have taken longer to freeze over. The result: Winter storms crossing the unfrozen lakes picked up so much more moisture that Buffalo has been experiencing record-breaking snowfalls.

Right now, said Lt. Stephen Martin, ice breakers are working in Green Bay, Wis., so that iron ore from Minnesota can be trucked there and loaded onto ore carriers that will head down Lake Michigan for Indiana. Later this spring, the ice on Lake Superior will break up and the ore boats can go back to Duluth.

The ice center analysts send advice to ships' captains about the best routes for avoiding bad ice. This is especially important for the supply ships that make the run up to the U.S. Air Force base in Thule, Greenland, and to those that stop in at military installations in northern Alaska.

One who didn't recently, because he wanted to save time, managed to punch a hole in his ship's hull and was set back a month waiting for repairs.

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