The U.S. agency that explores outer space is also probing another frontier -- the rapidly warming climate in Alaska and other parts of the Far North.
NASA has launched three Alaska-based projects to better understand how warming is changing the size and behavior of glaciers, the release of carbon gases from thawing permafrost and the interplay between sea ice, clouds and weather in and above the Arctic Ocean.
At a teleconferenced briefing on Tuesday, scientists working on the three NASA projects explained why changes on this part of the planet Earth are important to the space agency.
The polar regions are particularly important to NASA for many reasons, said Tom Wagner, cryospheric sciences program manager at the space agency's Washington, D.C. headquarters.
"One, they are a critical part of the Earth's climate system that we are only beginning to understand," Wagner said in the news conference. "Two, they are changing, and they're changing rapidly. And three, we know and we are learning more every day about the dramatic implications the change there has for the rest of the planet."
One project, being carried out by University of Alaska Fairbanks researchers, is using repeated flights and a laser altimeter to precisely measure glaciers in the state and monitor them for ice gains or losses. The project is part of NASA's larger Operation IceBridge, a multiyear campaign that uses aircraft to measure changes on the landscape and sea ice in both the Arctic and Antarctic.
Although each Alaska glacier has its own idiosyncrasies, as a whole they are noticeably affected by the warming climate, said Evan Burgess, University of Alaska Fairbanks scientist and member of the IceBridge Alaska team.
"Glaciers in Alaska are actually more closely tied and more sensitive to climate than we previously thought," Burgess said in the teleconference.
Relatively high-altitude glaciers away from tidewater are thinning fairly rapidly, Burgess said. "We have yet to find a single one that is actually growing," he said. "When we look at the collective group of them, they are all shrinking much quicker than we had thought."
Do not expect Alaska tidewater glaciers to continue dumping large amounts of ice at a furious rate into the sea, however. Those glaciers, for the most part, have already retreated so far inland that there is not much frozen volume left to fall off into the water, Burgess said. "They're kind of on the cusp of tidewater glaciers-slash-being not quite being a tidewater glacier, and that kind of is helping them be more stable," he said.
Even the much-studied Columbia Glacier, famous for shedding blue-white ice chunks into Prince William Sound and responsible for 1 millimeter of sea level rise in the past 20 years, will not continue its massive iceberg production. "That's probably going to stop in the next 20 years or so," he said.
Another project is examining permafrost and the extent to which carbon gases are escaping from it. The project, called CARVE -- for Carbon in Arctic Reservoirs Vulnerability Experiment -- is using aircraft to take measurements of carbon dioxide and methane at varying elevations above the permafrost.
Findings show that carbon dioxide and methane levels are very closely correlated with each other, and higher than would be expected in an unpolluted area of the world, said principal CARVE investigator Charles Miller, a scientist at NASA's Jet Propulsion Laboratory in California.
A separate project is studying sea ice, clouds and the atmospheric conditions and weather produced by the interaction. That project, called ARISE -- for Arctic Radiation-IceBridge Sea and Ice Experiment -- is testing out some complex theories about effects of dwindling sea ice on larger weather patterns.
"We have some expectation that less sea ice cover over the Arctic Ocean could lead to more clouds," Bill Smith, the principal ARISE investigator and a scientist stationed at NASA's Langley Research Center in Hampton, Virginia.
If so, that leaves questions: Will the increased cloud cover have a cooling effect by reflecting solar heat, or a warming effect by trapping heat from the surface below? "The data we're collecting from the C-130 are intended to help sort this out," Smith said.
Still looming are questions about the sea-ice melt and potential effects on climate and weather in latitudes far to the south.
"We have a tough time tying the changes that occur in the Arctic specifically to the changes in the rest of the atmosphere, because they're such large areas and making those teleconnections is difficult to do," Wagner said. For example, over the past winter, there was much attention paid to the unusual meanderings of the jet stream and the resulting unusual weather in much of North America.
Scientists have tried to correlate events, but also recognize that other factors in the Pacific and Atlantic oceans affect lower-latitude changes, he said.
"Whenever you read those studies in detail and what was said, people say, 'Look, this is the cutting edge of research, and it's going to take some time,'" Wagner said. "What I will say is that it's not the kind of thing where we can just throw up our hands and say, 'Oh, there's no influence.' We understand a lot about atmospheric circulation and we have every reason to believe that the changes in the Arctic are already affecting us right now."
Arctic sea ice coverage is currently approaching what is likely to be the sixth-lowest annual minimum on satellite record, according to the National Snow and Ice Data Center. This year, ice is particularly sparse north of Alaska and eastern Siberia, but heavier off of eastern Canada and Greenland.