North Pole Environmental Observatory

April 13, 2010

A winch at the National Science Foundation's North Pole Environmental Observatory is used to retrieve a mooring that has been collecting oceanographic data from the Arctic Ocean for a year. Photo: Peter West/National Science Foundation

American research teams returned this week to ice station Barneo, a Russian logistics hub floating on sea-ice covering the Arctic Ocean near the North Pole. There, they continue some baseline measurements of oceanic and atmospheric conditions collected since 2000. With National Science Foundation funding, the University of Washington’s Jamie Morison leads the North Pole Environmental Observatory (NPEO) effort, an international collaboration.

“Six personnel flew to Barneo on 10 April over the course of two flights,” wrote Tom Quinn (Polar Field Services), who is now positioned at Longyearbyen, on Norway’s Svalbard Archipelago, through April. Tom in Longyearbyen and Andy Heiberg at Barneo are coordinating NPEO logistics from both locations.

The armchair North Pole scientists among us will recall that the true course of work at ice camp Barneo is always a challenge, and so far, this year is no exception.

“During the evening/early morning a large lead opened up across the runway and through camp,” Tom wrote over the weekend. “The runway was 1.8km in length but it is now unusable. The field staff at Barneo have marked out a new runway and taken several passes on it with a bulldozer to groom it. The field staff are also moving structures such as the galley and berthing tents across the lead to consolidate the camp in one place.”

Over the next two weeks or so, NPEO researchers will pass between the Longyearbyen staging point and the ice camp Barneo, approximately 700 miles away. They will fly to the ice camp via a chartered AN-74, a Russian STOL jet airplane. (The An-74 gets its nickname, Cheburashka, from the large engine intake ducts, which resemble the oversized ears of the popular Russian animated creature with the same name.)

Members of the team will recover an instrumented mooring that has been fixed to the ocean floor some 2.5 below the surface since 2008. The mooring holds instruments that capture baseline measurements—ocean temperature and salinity, current strength and direction, and sea-ice conditions, for example. Other NPEO researchers will fly hydrographic surveys in a Twin Otter, deploying instruments that will collect similar information as they sink slowly through the water column. In addition, a MI-8 helicopter will land near individual instruments previously deployed; researchers will send a radio signal and the instruments will release their data payload, sending atmospheric, weather, sea-ice and upper ocean water column information to the team on the sea ice.


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.


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