Submarine mission to the Arctic.

Climb aboard a nuclear submarine for a chilling scientific cruise-- under the Arctic ice.

Ray Sambrotto is on the cruise of a lifetime. But Sambrotto, an oceanographer, is not basking in warm tropical breezes, piling up his plate at poolside buffets, or sunning himself on deck Instead, he and six other scientists are enduring frigid temperatures, eating canned meals, and barely seeing the light of day.

Their shin is the U. S. S. Pogy, a nuclear-powered Navy submarine. On August 27, they set out from San Diego, California, for a three-month exploration of the Arctic Ocean.

Why sail so far North? Over the past 30 years, oceanographers have mapped the Atlantic, Pacific, and Indian Oceans. They can describe how these oceans formed, how they interact with Earth's atmosphere, and what marine life swims below. "But in the Arctic, we're really at square one," Sambrotto says.

The main reason? The Arctic is covered by a permanent ice sheet that's up to four meters (12 feet) thick. This polar ice cap makes navigation very hazardous.

Other scientists have tried to study the Arctic while camping out on the ice. But brutal winds, sub-zero temperatures, drifting ice, and hungry polar bears pose chilling threats. Others have traveled to the Arctic aboard ice breakers--giant surface ships that smash through the ice. But ice breakers often get stuck.

In a submarine, however, "you can travel under the ice, break through it, and leave quickly" by submerging, says Mark Cook, a North Carolina State University marine electronics technician who's conducting experiments aboard the Pogy.

The scientists are borrowing the Pogy and a crew of 120 from the U. S. Navy. Since the end of the Cold War, the Navy has been looking for new, peaceful uses for its subs. The Pogy used to track potentially hostile ships through the Pacific Ocean.

In their new mission, the crew help with experiments. The plan is to collect data that can help scientists understand the geology of the Arctic, the effects of pollution on Arctic ecosystems, and the ways the Arctic affects the rest of the world.

Why do they care? Because the Arctic Ocean is as important to our world as the ocean water that laps up on U. S. shores, says Sambrotto.

DOWN 'SCOPE

You may think of the Arctic as some faraway, disconnected place. But look at the map on page 17 and you'll notice that the Arctic Ocean is surrounded by familiar continents: Asia, Europe, and North America. Everything that happens on these continents affects the Arctic--and the Arctic affects these lands, too.

For instance, scientists know that the Arctic Ocean floor is made up of shifting slabs of Earth's crust called tectonic plates--just like the rest of Earth's surface. But they don't know exactly how these plates move, or how they affect the surrounding continents.

To gather data, the Pogy scientists are using sonar to scan the seafloor (see SW 11/1/96, p. 10). They hope to map the Arctic's mid-ocean ridges--undersea mountain chains that mark the boundaries between tectonic plates. Understanding how the crust moves there may help scientists predict the consequences--say, future earthquakes or the movement of the continents.

OCEAN POLLUTION

The Arctic explorers are also investigating the impact of human acts--specifically the effects of pollution from nations surrounding the Arctic Ocean.

Four main rivers--the Ob, Yenisey, and Lena rivers in Russia and the Mackenzie River in Canada--flow northward and empty into the Arctic. These rivers carry industrial wastes like heavy metals and radioactive contaminants. Scientists want to know if and how these pollutants damages the Arctic ecosystem--the plants and animals that live there and interact with the environment

To find out, the Pogy scientists are measuring pollutant levels in the ocean water. They're also collecting samples of plankton, microscopic plants and animals that form the basis of the Arctic food web. If these tiny sea creatures are contaminated, the pollutants could travel through the food web to the fish, bears, and other predators--including Arctic-dwelling humans--that depend on the Arctic Ocean for food.

CLIMATE CONNECTION

The Arctic also plays an important role in Earth's climate control, says Gary Brass, executive director of the U. S. Arctic Research Commission, which coordinated the Pogy voyage.

Arctic ice, for example, reflects much of the Sun's heat energy back into space. This albedo effect, Brass says, helps keep our planet cool.

But if Earth's climate warms up due to the "greenhouse effect" (see SW 11/1/96, p. 7), we may be in for a polar meltdown. With the ice melted, the dark sea below will likely absorb heat instead of reflecting it. Presumably, says Brass, the continents surrounding the Arctic will then heat up even more.

To monitor the climate, the submarine crew is breaking through the ice at 15 scheduled stops along the voyage. The scientists climb out onto the ice, drill holes, and lower sampling bottles to depths of 460 to 610 meters (1,500 to 2,000 feet). Instruments on the bottles will provide temperature readings and other measurements.

The scientists will also make use of the submarine's signal ejectors-- small torpedo tubes. These will launch electronic thermometers to track the temperature as the sub cruises along.

It will probably take the Arctic explorers several months to decipher their data. But before they start crunching numbers, they'll make a stop in Pearl Harbor, Hawaii. After three months in the frigid Arctic, they've earned a tropical vacation!

RELATED ARTICLE: LIFE ON A SUB

Forget spacious beds, oak dining tables, and home-cooked meals. The seven scientists and 120 crew aboard the submarine Pogy are sleeping in triple-stacked bunk beds and eating canned and frozen foods in a mess hall smaller than a school bus.

"It's like being packed in a sardine can," says Jay Simpkins, a mechanical engineer on board, who's conducting ocean research for Oregon State University.

Scientists and crew must be constantly on guard for surprise drills. Every day, ship officers test shipmates' readiness for all kinds of disasters--from power loss to toxic gas contamination.

Keeping clean is no sweat. But scientists and crew must conserve water because machines aboard convert only 238 liters (63 gallons) of salt water to fresh water per person per day. That's less than half what the average American uses. The basic shower rules: wet down, turn off water, soap up, rinse.

The sub surfaces almost every day to let in fresh air. But thanks to machines that pull oxygen ([O.sup.2]) out the ocean water ([H.sup.2O]), there's always plenty of oxygen on board.

You can read postcards from the crew at the Navy Web site, http://www.hnl.mrms.navy.mil/ Click on the comsubpac link, then on current news & public information.