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Atop world, scientists ask why ice cap is melting
Monday, April 26, 1999 By Michael Woods, Post-Gazette Washington Bureau
ON THE BEAUFORT SEA -- A vast wasteland of ice stretches from horizon to horizon as the DeHavilland DHC-6 "Twin Otter" aircraft pushes north, hundreds of miles above the Arctic Circle. Barrow, Alaska, northernmost city on the continent, is just a memory.
Pressure ridges formed by the collision of miles-wide sheets of ice scar the surface at the top of the world. Inky-black ribbons of open water fissure the ice, reflecting the bright sunlight of an early arctic spring, where surface temperatures stand at minus 27 degrees Fahrenheit.
Fall under imagination's spell, and the ice camp materializing in the distance could be some lost way station in the exploits of Robert E. Peary or Frederick A. Cook. Ninety years ago this month, both explorers staked competing claims as the first to reach the North Pole.
"There it is," Navy Lt. Steve Mavica yelled through the roar of the Otter's engines. "That's APLIS, the ice station."
The Applied Physics Laboratory Ice Station is base camp for a research project called Arctic Ocean Science from Submarines -- SCICEX -- that is helping to answer critical questions about global warming. SCICEX is sponsored by the National Science Foundation and the Navy's Office of Naval Research.
SCICEX and other arctic research projects are hunting for explanations for a mysterious series of events that have unfolded at the top of the world.
During the last decade:
Are the changes part of a short-term natural cycle that persists for about 10 years and then swings back in the other direction?
Or are they omens of greenhouse warming, caused by human activity, that will persist and perhaps intensify?
Scientists say huge gaps in knowledge about arctic climate, ice cover and ocean circulation make it impossible to answer such questions.
"We know relatively little about the natural climate variations in the arctic compared to other regions of the globe," said arctic researcher Richard E. Moritz, of the University of Washington.
That's where research stations such as APLIS become critical.
On this recent trip, the Otter approached the station by circling a ramshackle clutch of tents and plywood huts as wind-whipped smoke rose from their sheet-metal chimneys. The plane then landed on the six-foot-thick shell of ice -- all that separated APLIS from 9,000 feet of water.
Capt. Jeffrey A. Fischbeck of Edgewood, officer in command of SCICEX, described it as a key element in a new scientific effort to use the arctic regions as a vast scientific research laboratory.
"The research done here may have a bearing on the lives of people everywhere in the 21st century," said Fischbeck, who directs the Navy's Arctic Submarine Laboratory in San Diego. "This is a new era in our interaction with the arctic regions."
Replacing past arctic heroes such as Peary and Cook are a new generation of explorers -- oceanographers, climatologists, geophysicists, glaciologists and other experts.
Scientists regard the arctic as one of the best places on Earth to study climate change.
"Global climate models have predicted that the arctic may be very sensitive to climate change," said Dr. Taneil Uttal of the National Oceanic and Atmospheric Administration. "It may be the region of the planet where climate change will happen first, as well as the region where changes may be most extreme."
SCICEX is a major part of the effort to seek answers to several vital questions: Will severe global warming occur in the 21st century? How will it affect society? Will the effects justify proposals that the United States and other industrialized countries take a major economic hit and sharply reduce use of gasoline, coal and oil to avert global warming?
When burned, these fuels release carbon dioxide. Carbon dioxide has been building up in the atmosphere, where it traps heat somewhat like the panes of glass in a greenhouse. Climate models, which are elaborate computer programs, have predicted that Earth's temperature could rise by about 2 degrees Fahrenheit in the 21st century as a result of emissions of carbon dioxide and other gases. The potential consequences include flooding of coastal areas and possible loss of agricultural production in the American breadbasket.
Since SCICEX began in 1995, Navy nuclear submarines have swapped some of their armaments for scientific instruments for several weeks each year. Patrolling under the arctic ice sheet, they have used sonar and other sensors to monitor the depth of the arctic ice sheet, water temperature, saltiness and other conditions.
As a finale to the project, the 1999 SCICEX expedition, last in the program, was expanded to include APLIS, which was built in March by the University of Washington's Applied Physics Laboratory. Dozens of scientists and support personnel have worked at the station, braving rustic living conditions and wind chills of minus 70 degrees that freeze exposed skin in seconds.
Among the challenges: No water for bathing, unheated outhouses where clients dare not tarry, and hungry polar bears that make a high-powered rifle mandatory equipment when walking to nearby research sites.
"This year's ice station substantially increased SCICEX's capabilities," said Jeffrey L. Gossett, head of operations at the submarine laboratory. "It allowed us to move scientific teams to and from the submarine without requiring them to make a long commitment to full voyages as in the past."
How does a 5,000-ton nuclear attack submarine patrolling under six feet of ice transfer passengers? Scientists and guests at APLIS got a dramatic demonstration early one morning when the Hawkbill arrived to swap chief scientists.
Technicians lowered a sonar buoy through the ice about a half mile from the ice station to guide the sub, which inched upward until the top of its "sail," or conning tower, just touched the ice's undersurface. Then the sub blew water from its ballast tanks and partially surfaced. Its great heave thrust the ice upward as the Hawkbill's black sail, gleaming with a sheen of water, pushed through the ice.
APLIS workers then spent a half-hour with a chain saw cutting a hole through the ice so the Hawkbill's hatch could open.
After three hours waiting in wind chills of minus 85 degrees, observers who gathered for the surfacing eagerly scrambled down the hatch into the blessed warmth. In the sub's humid air, steam rolled off their frozen, heavily clad bodies, and instantly a thick layer of frost formed on eyeglasses and cameras.
Part of the SCICEX mission is to help determine whether the changes being seen in the arctic are coming from natural causes.
Dennis Conlon, who manages an arctic research program for the Office of Naval Research, said one possible cause of the ice thickness and temperature changes could be a phenomenon called the North Atlantic Oscillation (NAO).
NAO is a north-south contrast in atmospheric pressure in the North Atlantic Basin. It occurs when atmospheric pressure is lower than normal in the northern part of the basin near Greenland and higher than normal in the subtropics near the Azores.
The pressure differences then flip, or oscillate, with higher pressure in the north and lower pressure in the south.
The oscillations affect temperatures, storminess and other weather conditions over eastern North America and Western Europe.
Conlon said the NAO runs on roughly a 10-year cycle. The cycle is about due to reverse, and the shift could mean a return of colder, saltier water and thicker, more extensive ice cover.
"If the warmer conditions continue this year, it could be a very definite sign of global warming," Conlon said. "We'd have to seriously ask if there is a tendency now toward melting of the ice pack and rising sea levels."
Moritz and other scientists say they may need years of additional data analysis to distinguish natural trends from any due to human activity.
"The single most important set of observations needed at present are observations of ice thickness in the Arctic Ocean on a regular basis such as those made from SCICEX," said Judith Curry, of the University of Colorado.
Where will future measurements come from?
SCICEX is at the end of its planned five-year program, and there is uncertainty how much global warming research the American fleet of attack submarines can accommodate in the future, because scores of the vessels are scheduled to be decommissioned over the next few years.
Conlon said the National Science Foundation was conducting a feasibility study on acquiring a Sturgeon-class sub for use as an oceanographic research vessel. But several scientists expressed concern that costs would be excessive.
Another possibility involves expanded use of automated instruments that constantly monitor changes in Arctic Ocean temperatures and extent of ice cover. The United States and Russia have agreed to cooperate on one such effort that will deploy a network of underwater sensors in the Arctic Ocean. Linked to the shore with fiber optic cables, the sensors will build a long-term database of information.
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The layer of year-round sea ice that covers much of the Arctic Ocean has become an average of 10 inches thinner.