On Frozen Ground

January 27, 2010

Dr. Vladimir Romanovsky, director of the Permafrost Laboratory at the University of Alaska, Fairbanks, conducts permafrost research on the North Slope of Alaska. Photo: courtesy Dr. Romanovsky

By Marcy Davis

Scientists have long known the importance of permafrost, a layer of frozen soil in circumpolar regions that is one of the first victims of a warming climate. For more than 50 years, researchers have dropped temperature sensors into boreholes at various depths all around the world to track the state of the permafrost. But much of this data remains isolated and unpublished, inaccessible to anyone hoping to track global temperature change.

But if Dr. Vladimir Romanovsky, director of the Permafrost Laboratory at the University of Alaska, Fairbanks, Geophysical Institute, has his way, an international collaboration between the United States and Russia could produce the first international permafrost network. Call it the Cold Cooperation, the scientific opposite of the Cold War.

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As one of 35 National Science Foundation-supported Arctic Observing Network (AON) projects, Romanovsky’s work will integrate 80 Alaskan borehole sites—locations where researchers study permafrost, with about 160 Russian borehole sites. This initial step will provide the baseline temperature estimates necessary to evaluate future rates of change, according to Romanovsky.

“Permafrost data is beneficial to any ecological or carbon cycle study,” said Romanovsky. “Providing our data to other studies is important. In turn, we want to know about ecosystems, and have to be able to take into account hydrology and vegetation changes. Establishing this network will facilitate better communication and data sharing.”

Improved Modeling

In addition, the network will make permafrost data more available to climate modelers, which should improve researchers’ abilities to predict and understand the interaction between permafrost and climate.

Permafrost

Permafrost, defined as any earth material at or below 0°C for two or more consecutive years typically forms in the Arctic, subarctic, Antarctica, and in high alpine regions. It can vary in extent and thickness, and the largest area of continuous permafrost underlies the Tibetan Plateau in China with an area totaling 2.5 million square kilometers, more than twice the size of Alaska. Eastern Siberia holds the record for thickest permafrost at 1400 meters.

Domestically, permafrost in the Rocky Mountains of North America is laterally discontinuous, or patchy, with thicknesses ranging from less than one to several meters. Where temperatures are consistently colder, the permafrost is thicker.

Along Alaska’s North Slope, permafrost is continuous except under big lakes and rivers, which do not freeze completely to the bottom in winter; water acts as a source of heat to the ground below. At Prudhoe Bay, permafrost is 660 m thick. In Alaska’s interior, permafrost is discontinuous, found mostly in stands of black spruce and in low valleys where moss and peat are prevalent; Aspen groves and south-facing slopes rarely have permafrost.

Changes To Frozen Ground

Romanovsky has observed temperature changes in Alaskan permafrost, but added that interpreting those changes is difficult. Natural oscillations that last multiple decades show the same patterns; researchers need more time to understand whether or not their results result from longer-term, global climate change.

“The cycle seems on an upward trend,” he said. “What we see could be global warming, or could just be a longer natural oscillation. What are interesting are the hemispherical similarities between Alaska and Russia. Models can help explain past temperatures and future projections regionally and globally. So, we need to keep making measurements.”

Threats To Permafrost

One of the biggest concerns about warming permafrost is that greenhouse gases such as methane now sequestered in permafrost may be released back into the atmosphere, thereby creating a positive feedback for future climate warming. Another worry stems from the potential impacts of thawing permafrost on the communities, which could include localized but important changes in ecosystems and infrastructure.

Romanovsky says, “We are seeing changes in permafrost, but they are slowly evolving changes. There could be dangers for people who live in permafrost regions so they should be aware of the problem, but should not panic. Instead, we need to focus on mitigation, and working together. We have some ways to tackle these problems, but it takes time and money.”


Surviving the Break-up

January 19, 2010

Scientific and traditional expertise find mutual benefit in sea-ice study

By Marcy Davis

Walk on water: PI Hajo Eicken at the Barrow sea ice mass balance site in June 2008, during the melt season. All photos courtesy Matt Druckenmiller

Unlike most other solids on Earth, ice floats. As water freezes, it expands to include lots of airy pockets, which means that ice is less dense as a solid than as a liquid. Fresh water ice is relatively dense and impervious while sea ice, ice that freezes directly from mineral-rich ocean water, develops interconnected sand-to-finger-sized channels that help control its decay during warm months. Through the Seasonal Ice Zone Observing Network (SIZONET), one of about 35 National Science Foundation-funded projects in the Arctic Observing Network, Hajo Eicken, research associate Chris Petrich, and graduate student Matthew Druckenmiller (all from University of Alaska, Fairbanks, UAF), study the small-scale properties contributing to the formation and disintegration of arctic coastal sea ice. In addition to gaining a better understanding of the role of sea ice in the global climate system, Eicken’s team hopes to help coastal communities which rely on sea ice–like Barrow, Alaska–by forecasting break-up, the time of year when seasonal ice begins to melt.

Off the village of Barrow, BASC employee Michael Donovan navigates a boat to a grounded ice foe in July 2008 so that Matt Druckenmiller can take an ice core.

Off the village of Barrow, BASC employee Michael Donovan navigates a boat to a grounded ice foe in July 2008 so that Matt Druckenmiller can take an ice core.

“Sea ice provides many animals, humans included, a surface on which to live, travel, and hunt. We want to understand how sea ice decays from a materials perspective,” explains Eicken. “We also want this information to be useful to local communities for whom break-up is important for hunting and whaling. We spend time trying to understand how people in Barrow use the sea ice in their daily life so that we can define and redefine our models and projections for how the ice will behave.”

Eicken’s group studies the seasonal sea-ice zone, which includes land-fast ice (ice that freezes to the coastal shoreline) and drift ice (ice that floats on the water surface). In contrast to multiyear ice, which does not melt in the summer, seasonal ice builds up during winter months and melts in summer months. This means that seasonal ice is far less stable. From a human perspective, then, break-up can be dangerous because how the ice melts varies from year to year and progresses over the season.

UAF sea ice team conducting ice thickness measurements and ridge surveys in the landfast ice near Barrow in June 2007.

Break-up begins with melting on the sea-ice surface. If the meltwater is retained, it pools on the surface. Because of the darker color, the ice surface ponds absorb heat and create a positive feedback for even more melting.

“We study seasonal ice rather than multiyear ice because we understand far less about seasonal ice. The forces which control breakup are highly variable – sunshine and warmer temperatures, tides, and storms all contribute, but to what degree remains less clear. But from a Search and Rescue perspective, it is very important to the Barrow community to have as much information as possible during break-up, especially since the coastal land-fast ice and ice drifts have become much more unstable over the last 20 years,” Eicken says.

Chris Petrich and BASC Bear Guard Herman Ahsoak measuring level ice thickness near a grounded ridge in June 2007.

Eicken, Petrich and Druckenmiller use satellite data to map ice conditions along the coastline near Barrow where locals use established ice trails for hunting and whaling during break-up. Although satellite data provides a decent regional picture, the relatively low resolution equates to substantial real-life discrepancy. In addition to field campaigns aimed at measuring temperature and albedo of ice surface ponds and ice thickness, indigenous ice expert and ex whaling captain Joe Levitt provides daily ice observations to help integrate and ground-truth satellite and field data or break-up forecasts.

These are especially useful to local communities during spring whaling season, when hunters establish camps on the sea ice. “Matt [Druckenmiller] created maps showing ice thickness along whaling trails on the land-fast ice off Barrow. These maps have proven useful for the community who might have as many as 200 people spread out over a 20-mile area or more during whaling season. This is a big safety issue for them,” says Eicken. “We’re posting satellite and radar images along with sea ice trail maps on the Internet and holding workshops with folks in Barrow both to educate them about how to use these data as well as to help us refine our forecasting models.”

The sea ice trail maps give Barrow-area whalers important information about ice thickness around their sea-ice trails.


A Caribou View

August 19, 2009
 “We stopped to take some pictures and this caribou crossed right in front of us,” reported Brad Stefano (CH2M HILL safety manager), who snapped these shots.

PFS' Jay Burnside exchanges glances with a large caribou. Pictures by Brad Stefano

Last week a group from the National Science Foundation and CPS visited Toolik Field Station (the University of Alaska’s research outpost on the north slope of the Brooks Range).  Because you can’t get there from here, we flew to Prudhoe Bay up on Alaska’s northern coast, borrowed CH2M HILL vehicles, and drove to and from Toolik on the Dalton Highway, which parallels the trans-Alaska oil pipeline.

Toolik is a bit over 100 miles south of Prudhoe Bay, but it’s a bumpy three-hour drive over the so-called Haul Road, which was built to carry oil workers up to the fields in Prudhoe Bay. But what the Haul Road lacks in comfort it makes up for in scenery, and last week was no exception. Our group was treated to a caribou feast—for the eyes, that is—as multitudes could be seen alongside the road on their seasonal migration.  

“We stopped to take some pictures and this caribou crossed right in front of us,” reported Brad Stefano (CH2M HILL safety manager).

“We must have seen hundreds of caribou,” he continued. “We were traveling in a convoy of three trucks, but they didn’t seem to care about us—they weren’t afraid at all. That seemed a little ironic because there were also a lot of bow hunters around.”

Dude, act like you don't see the truck. Or the hunters.

Dude, act like you don't see the truck. Or the hunters.

The group watched a dozen or so bow hunters dragging a felled caribou along the road.  As an aside, guns are illegal near the trans-Alaska oil pipeline, which runs about 800 miles from the southern coast of Alaska at Valdez to Prudhoe Bay where the oil fields are.


Where in Alaska is Matt Irinaga?

April 29, 2009

Alaska staffer Matt Irinaga has spent much of this spring out of the Fairbanks office helping NSF-funded researchers mount field efforts all over Alaska.

In late March, Matt headed to Nome and Shishmaref to help put in a field camp at nearby Cape Espenberg on the northern Seward Peninsula for (U Alaska) Katey Walter’s methane study. The entire field plan was slowed by the untimely eruption of Mt. Redoubt to the southeast on the Kenai Peninsula. One volcanic volley on March 26 forced the cancellation of cargo flights packed with camp and science gear.

An aerial view of Alaska's Mt. Redoubt eruption, which began on March 22, 2009.

An aerial view of Alaska's Mt. Redoubt eruption, which began on March 22, 2009.

Still, after a short delay, and with the volcano still rumbling, Matt, Tim Tannenbaum (CPS field camp manager) and the advance team arrived at the field site and got the camp established.

The full Walter research team arrived a few days later and began daily excursions from the camp for lake sediment coring, GPS and landscape feature surveys, sediment and biogeochemical sampling, and more. The team extracted lake sediments and permafrost samples, which are being shipped to the University in Fairbanks, the Alfred Wegner Institute in Germany and the LacCore facility in Minnesota for storage and later analysis.  For an on-the-ground view of Walter’s research, read and watch a Los Angeles Times Story written by a journalist who visited the researcher in the field last fall.

 

Guido Grosse (left) and Ben Jones take a break from extracting sediment cores as part of the Walter research project.

Guido Grosse (left) and Ben Jones take a break from extracting sediment cores as part of the Walter research project.

After establishing the Walter camp, Matt Irinaga met University of Alaska permafrost outreach troubadour Kenji Yoshikawa in Kotzebue. The two then flew to Point Hope to install permafrost monitoring instruments near village schools.

 

Welome to Point Hope,one of the remote villages where Kenji Yoshikawa installed permafrost monitoring instruments this spring.

Welome to Point Hope,one of the remote villages where Kenji Yoshikawa installed permafrost monitoring instruments this spring.

Yoshikawa draws children and their teachers into his work by showing them how to maintain and store data collected from the stations—and by appealing to their love of superheroes with his Tunnel Man alter ego.

Kenji Yoshikawa reviews with a student how to interpret data from the permafrost monitoring station.

Kenji Yoshikawa reviews with a student how to interpret data from the permafrost monitoring station.

One may sense his legendary, indefatigable spirit by viewing the Tunnel Man videos, available via Yoshikawa’s permafrost outreach Web site.

From Kotzebue, Matt traveled with seasonal CPS staffer Erik Lund to Deadhorse. There, the two established a laboratory for polar bear researcher, U of Wyoming’s Hank Harlow. Harlow’s team is working with the United States Geological Survey this spring and summer to monitor polar bears living on the sea-ice offshore from Prudhoe. Harlow leads an effort to understand how loss of sea ice might be impacting polar bears that use the ice as a hunting platform. His group is in Deadhorse locating, capturing, tagging, examining and taking samples from polar bears; they will return this summer and in the fall to recapture some of the bears, repeating the examinations and measurements for comparison with the earlier data. Harlow hypothesizes that bears having difficulty finding food due to loss of access to prey as a result of sea-ice loss may enter a state of “walking hibernation.”

To round out the spring, Matt traveled to Bethel and met up with Mandy Van Dellen and her assistants working with U of Nevada’s Jim Sedinger on his long-term study of reproductive strategies in Black Brant Geese.  

Mandy Van Dellen digs out camp.

Mandy Van Dellen digs out camp.

The group staged at Chevak for their snowmachine put-in to a site along the Tutakoke River on the Bering Sea coast.

Kids in Chevak greet Matt and crew.

Kids in Chevak greet Matt and crew.

Sedinger’s long-term study tracks how reproduction impacts the overall health and survivability of the parent—and how that, in turn, impacts productivity and survival in subsequent years. The team will be in the field until late July closely monitoring a population of banded birds, from nest building through fledging processes.

Dan Honne, Howie Singer, Mandy Van Dellen, Matt Irinaga, and Adam Stewart in the field.

Dan Honne, Howie Singer, Mandy Van Dellen, Matt Irinaga, and Adam Stewart in the field.

 


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