CORVALLIS, Ore. - For the past 10 years, Kelly Falkner has studied water circulation patterns in the Arctic Ocean, which acts like a big valve and influences ocean circulation and climate throughout the entire globe.
And during the time she has been observing the Arctic, Falkner has witnessed significant changes, the Oregon State University oceanographer said today at a meeting of the United States Arctic Research Commission on the OSU campus.
"During our 2003 cruise to Nares Strait, we were able to get our ship further into the Petermann Gletscher Fiord (a glacier off northern Greenland) than any ship has ever gone before," Falkner said. "This is because the floating tongues of the continental ice sheet are retreating all around Greenland more than they ever have in recorded human history."
The U.S. Arctic Commission's annual fall meeting is in Corvallis, Ore., this year, where the seven-member group heard reports from more than a dozen Oregon State University scientists involved in Arctic research. The commission, which advises the president and Congress, includes four members from academic or research institutions, two from private industry undertaking commercial activities in the Arctic, and one from the indigenous residents of the Arctic.
Falkner, who is involved in two major Arctic initiatives funded by the National Science Foundation, outlined her research through which she can trace the origins of Arctic waters hundreds of miles from their sources by their naturally occurring chemical signatures.
The ratio of stable oxygen isotopes in water, for example, can tell scientists if the waters in a given part of the Arctic came from river water or melted sea ice. The nutrient levels reveal if sea water originated from the Atlantic or the Pacific Ocean. And whether rivers drain from Eurasia or North America can be traced by their levels of barium and their alkalinity.
Falkner and colleagues in OSU's College of Oceanic and Atmospheric Sciences and elsewhere are mapping the complex circulation patterns of the Arctic Ocean and how they are changing. It is incredibly important work, experts say, because small changes in the Arctic can have large implications.
"Ten percent of the world's river water drains into the Arctic, which represents just 1 percent of the world's ocean volumes," Falkner said. "The water flowing out of the Arctic can have impacts on ocean circulation, and thus climate, throughout the world."
Much of the news media coverage on global warming has focused on the potential for rising sea levels, Falkner said. For sea levels to rise, land-based glaciers or snow would have to melt. Less attention has been paid to the melting of sea ice, which may not raise sea levels but could dramatically affect ocean and atmosphere circulation - and the Earth's heat balance, she pointed out.
Falkner said that since 1978, when satellite measurements of Arctic ice first became available, the overall ice cap has shrunk more than 8 percent each decade. Some scientists feel enough ice has gone to create an "albedo threshold," which means it may not stay cold enough for a long enough period to re-establish the lost ice.
"Sea ice with snow on it reflects up to 90 percent of the energy from the sun," Falkner said. "Water, on the other hand, absorbs 70 percent or more of the incoming sun energy. So when there is a lot of ice, the heat is reflected. Now that the ice is receding rapidly, the water is absorbing more heat, and it becomes that much harder to re-establish that ice."
Falkner began her work in the Arctic during the early 1990s, when she received a Young Investigator Award from the Office of Naval Research to begin sampling Arctic rivers to determine their chemical signatures. One of the goals of that research was to monitor potential spreading of Russian nuclear waste in the post-Soviet Union era.
Now her focus is on understanding Arctic circulation and what drives its variability. Falkner and her colleagues are halfway through a five-year NSF grant to study fresh water fluxes into the North Atlantic east of Greenland in the Nares Strait. That research was stalled this spring when most of the team's equipment was blown away by extraordinarily strong winds.
"There were 80-mile-per-hour-plus winds, equivalent to a category-2 hurricane, that literally blew everything away," Falkner said. "Fortunately, folks managed to hang to one shelter and no one was killed or injured in the fierce cold. We were unable to check the instruments we had moored below the ice, but luckily we put extended batteries in them last year as a contingency.
"People are beginning to think that the Arctic is an accessible place, but it's not," she added. "It is very complex and you always have to have great respect for it."
Falkner and her colleagues have another cruise lined up for August of 2006 to check the instrumentation that will tell them more about the changing currents of the Arctic Ocean.