Dangerous ice conditions in Davis Slough off the Tanana River in early December. Ice conditions like this make traveling along rural Alaska’s icy lakes and rivers hazardous. Photos courtesy Knut Kielland

Each winter as the temperatures in Alaska dip well below zero, the frozen rivers and lakes become highways and byways for many rural Alaskans. Just a short distance outside Fairbanks, one of Alaska’s largest cities, the lack of traditional roads and bridges reminds one just how rural and rugged a large part of Alaska is. With few traditional roads, many rural Alaskans navigate the seemingly frozen bodies of water on snowmobiles and dog sleds.  And all too often they come in contact with dangerous ice.

This is something ecologists Knut Kielland and his colleague Bill Schneider, an oral historian, know all too well. Kielland and Schneider, both avid dog mushers and researchers at University of Alaska, Fairbanks (UAF), have been criss-crossing the Alaska countryside along the Tanana River outside of Fairbanks for nearly 25 years. During that time the two have certainly run into their fair share of dangerous ice, but there were several unusual phenomena associated with dangerous ice that piqued their interest.

Knut Kielland came up with the idea to study the phenomena behind dangerous ice while dog mushing. Here he is guiding his team through overflow on the Anaktuvuk River on Alaska’s North Slope.

Degrading Ice

At 584-miles long, the Tanana River is a natural force that cuts through the landscape of central Alaska. During the winter the Tanana River exhibits a wide variety of dangerous ice conditions, ranging from overflow (water on top of the ice surface covered by dry snow) to shell ice (ice with air pockets underneath). “The most insidious ice condition is degrading ice,” Kielland said. “This condition refers to ice that forms normally during freeze-up and represents a safe travel surface in early winter. However, as the name implies, degrading ice exhibits dangerous thinning during mid-winter even at very cold (-30°C) air temperatures. The physical mechanisms behind this phenomenon and the distribution of such ice conditions are a major focus of our project.”

With support from the National Science Foundation, Kielland, Schneider and a multidisciplinary team of researchers set out to study and map the physical conditions behind winter dangerous ice conditions, as well as document local knowledge and observations across a 200-mile study area near the Tanana River. The data from the project will help scientists understand the forces behind dangerous ice, and give rural Alaskans tools that may improve public safety.

A Complex Issue Needs a Complex Approach

Kielland wanted to study dangerous ice from multiple angles, including human interactions with this natural force. To do that, Kielland paired teams of natural scientists with oral historians and ethnographers to take a holistic approach.

“In terms of the multidisciplinary approach, we’re talking about climatology, hydrology and the physics of snow and ice—that’s the natural science part. In terms of the social science, it’s both the science of going about how to collect oral histories and learning about how residents view and experience their environment, and more directly in terms of how they experience the changing winter conditions, particularly in regard to snow and ice conditions,” Kielland explained.

Sam Demientieff of Fairbanks inspects ice degradation in Moe Slough, February, 2010.

Community Involvement

Involving local communities in the study area has been a key part of the dangerous ice project.  Many of the villagers and townspeople have traveled the frozen rivers and lakes for decades and have valuable knowledge and insight that machines and computers simply can’t duplicate.

To gather data on how locals call upon years of experience and training to frame their descriptions and evaluate ice conditions, Kielland looked to his longtime friend and oral historian Bill Schneider to record interviews with locals. Having lived and worked in Alaska for decades, it was relatively easy to tap the wealth of knowledge about rural Alaska’s frozen highways.

Residents of Manley Hot Springs meet to discuss the ice conditions along the river trail between Manley and the village of Tanana. LPictured from left oto right: are, John Dart, Espen Jervsjö, and Frank Gurtler (Manley), and Charlie Wright (Tanana).

“Because we’ve lived here for a while, we have friends and acquaintances—and acquaintances of acquaintances—in a variety of communities. We were very fortunate that we could pretty much come into a community and establish a rapport with them,” Kielland said.

Ice Interviews

The team worked with communities in Fairbanks, Manley and the village of Tanana to gather their observations on the distribution and abundance of dangerous ice phenomena and how they impact  subsistence activities and travel throughout the winter. With help from Karen Brewster, a research associate for the Oral History Program at UAF, the team has hosted several workshops and interviews in the field with river travelers, the results of which are now being posted online.

Research associate Karen Brewster films interviews with Sam Demientieff (left) and Wally Carlo (right) on the Tanana River, March 2011.

“We  do semi-direct interview [s], take a lot of photographs and videotap[e]ing of areas and interviews,” Kielland said.  Interviews and photos from the dangerous ice project are made publicly available through the University of Alaska Fairbanks’ Project Jukebox.

The combination of physical data and recorded oral histories has started to crack some of the mysteries of dangerous ice, shedding new light on the phenomena and how rural Alaskans deal with it.

Cracking the Ice

Some of the initial findings are a bit of a surprise to Kielland and his colleagues. Initially, he hypothesized that dangerous ice occurrences were tied to shallower (< 1 m) portions of the river more susceptible to melting from below due to ground water upwelling. However, that’s not always the case. The team has observed cases of dangerous ice in deeper waters (> 3 m).

Kielland has also documented very localized instances of dangerous ice where, “it’s almost like somebody sat down at the bottom [of the river or lake] with a laser and shot a hole in the ice. Hydrologists on the project are still working to understand the physics behind such localized events.

“We’re learning about the phenomena, about how wide- spread it is, and we’re learning about how people deal with it—though mostly they just want to stay far away from it,” Kielland said. “We don’t know much about how it has changed through time yet, but we hope our conversations with local residents can shed further light on that.”

Although winters in Alaska are getting warmer on the whole, dangerous ice phenomena aren’t necessarily a direct consequence of climate change.

“Winters in Alaska are getting warmer and climate predictions call for more snow. Both of those factors will probably exacerbate the situation, if anything, but we don’t consider this a direct consequence of warming. As I mentioned, we see the phenomenon even when it’s very cold out,” he said.

Lessons Learned

With the second year of the dangerous ice project now coming to a close, Kielland and Schneider hope to extend it for one more year to continue unraveling the mysteries behind dangerous ice.

The lessons learned from this project will not only tell us where dangerous ice is located and it’s potential causes, they will also help rural Alaskans avoid a wintertime problem that claims lives every year.

“We hope that at the end of the day, there will be an improved understanding from both our and their [rural Alaskans’] point of view about the nature of the phenomenon and how it’s distributed along the length of the Tanana that many of them travel,” Kielland said. For more information about the Dangerous Ice project (still under construction), visit: http://jukebox.uaf.edu/dangerice/start.htm. –Alicia Clarke

Comments (1) Dec 05 2011

PolarTREC teacher spent his summer “under this mass of moving ice”

PolarTREC teacher Michael Lampert at the Engabreen Glacier. All photos: Michael Lampert

Buried two hundred meters below Engabreen Glacier, one of a handful of outlet glaciers that drain northern Norway’s Svartisen ice cap, is the Svartisen Subglacial Laboratory, one of the world’s most unique settings for glaciological research.  Just north of the Arctic Circle, the facility came online in conjunction with a new hydro-electric power plant in 1993. An elaborate network of more than 100 km of subglacial tunnels funnels glacial meltwater through the mountain to turbines at the Glumsfjord Kraftverk power station near the glacier base—and allows researchers direct access to the underside of the glacier.

Living quarters and a science lab are housed within barracks-like structures in a tunnel below the surface near the glacier’s origin. The only light is the eerie yellow glow emitted from sodium vapor lamps and headlamps affixed to scientists’ hardhats.

The Svartisen Subglacial Laboratory houses underground labs and living space.

Michael Lampert, a 2011 PolarTREC teacher* from West Salem High School in Salem, Oregon, who joined PI Neal Iverson (Iowa State University) and team on this year’s field expedition, describes his first impression of the lab:

“A helicopter took us up to the top of [the] glacier where we were to enter the tunnel to the Laboratory. I kept looking for a grand entrance, but when we arrived it was just a post with a doorway. We shoveled out a bunch of snow so we could get the door open then walked about 100m through a corrugated pipe that opened into a large room,” Lampert explains.  “It was a little like being in a sewer – dark, drippy, cold, humid air that is very still. You can always hear water rushing through the tunnels. It’s a very odd feeling. There was this unbelievably strange emptiness. I wasn’t expecting it.”

Svartisen's foyer...

Lampert joined Iverson on the latter’s NSF-funded project to understand how, and how fast, Engebreen Glacier moves. During underground stays of up to three weeks at the subglacial lab, the group works at the glacier-bedrock interface, measuring water pressure and microseismicity, tiny earthquakes associated with glacier movement. Data obtained at Svartisen provide fundamental information about variability in glacier movement, information Iverson hopes will translate to long-term predictions about the ice sheets covering Greenland and Antarctica, and their potential contributions to sea-level change.

Lampert mucks out the tunnel.

“The idea here, the overall goal, is to stimulate a rapid glacier movement event by pumping water under the glacier for an hour while measuring the resulting microseismicity,” explains Iverson. “We measure water pressure in pump tests and embed accelerometers in the glacier to monitor ice acceleration. We then correlate these motion data to seismicity measured in the tunnel and on the glacier surface. We manipulate the system to try to understand it better. We are trying to calibrate motion in a very large-scale laboratory so we can apply results to other glaciers.”

Melting last year's ice.

Donning rubber boots and suits to protect them from mud and water, researchers worked to free instruments left in the glacier ice last summer for maintenance and repairs. To get at the equipment, the team first had to melt free a steel door separating the tunnel from the glacier. Using relatively hot water (sixty degrees) from a fire hose directed at the door for an hour, Lampert , who has a background in physics, got his first up-close glimpse of the Engabreen’s underbelly. In a May 2 PolarTREC journal entry he wrote:

“The very bottom of the glacier is a mix of sediment and debris but there is a sudden line of clear glacier ice, often you see lines like this on icebergs that have calved into the ocean. The blue ice has a magical appearance when illuminated with a flood light.”

The glacier's base is mixture of ice and sediment.

Next, the team melted horizontal and vertical shafts through the ice to expose boreholes in the rock through which instrumentation, cables, and wiring pass from instruments embedded in the glacier to lab computers. During the year, the holes become clogged with ice that must be removed periodically. It’s a constant fight against moving ice, which can close off passageways at rates of 1-2 meters a day.

“Ice [that is] under 200 meters of pressure oozes like toothpaste. [It’s] not brittle like the ice in your freezer,” explains Lampert. “Once the sensors are in the glacier and we stop melting, the ice moves back in. The glacier is moving so the ice will ooze around you in the course of a day. You can see a difference within an hour. It’s kind of creepy. Sometimes I would sit in a space in the ice and close my eyes. I would think about just exactly where I was – under this mass of moving ice and that really put me in touch with Earth’s geology. That was one of the coolest things ever!”

Enjoying the view from outside the lab entrance.

Instrumentation includes a friction plate, a granite-topped metal disc about a foot in diameter and loaded with sensors that measure the force of the glacier as it slides over bedrock. The plate, the only one of its kind, also contains a water pressure sensor and an acoustic sensor that ‘listens’ to the glacier’s sounds as it moves past. Other sensors include accelerometers in palm-sized capsules that monitor ice motion.

“Some accelerometers have cable tethers that are fed through boreholes in the underlying rock to lab computers.  Some transmit wirelessly through the tunnel. Both types have advantages and disadvantages. There is lots of screwing around with electrical stuff in conditions a degree above freezing and 100% humidity,” Iverson says.

Accelerometer maintenance is serious business.

Once instrumentation is tested and reinstalled, the shafts are left alone so that the ice “heals.” Then water is pumped through the tunnel at the base of the glacier and the team waits for data.

“We know for certain that moving ice produces seismicity and the character of our data seem to indicate motion of ice as opposed water, “ explains Iverson. “We are still working out what our data mean. The signals look like we are recording the basal motion of the glacier as it slides over rock, but we are working through the details as the data can be very noisy.”

Other sampling efforts include ice coring, sediment and geologic analyses.

Miriam Jackson takes an ice sample.

As for Lampert, he’ll bring lots of stories back to his community and classroom this fall.

“The whole thing was out of the world – so totally surrealistic! These scientists are getting at the real fundamentals of science. I want my students to really understand that applying science in the field is the best part. Then there’s the living in a tunnel – there’s a psychological effect with it that I didn’t expect. When we finally walked out from this place of 24 hours of darkness into the 24-hour day of the polar summer, it was wild…quite a metaphor to walk out of total darkness into light, from nothingness to life.”—Marcy Davis

PolarTREC (Polar Teachers and Researchers Exploring and Collaborating) is funded by the National Science Foundation’s Office of Polar Programs and managed by the Arctic Research Consortium of the United States, or ARCUS. The program aims to give teachers professional development experiences conducting research in the polar regions with career scientists to boost the teachers’ content knowledge and to give them hands-on experience in scientific inquiry. ARCUS is accepting applications through the end of September from teachers and researchers interested in participating in the PolarTREC program during the 2012-2013 research season. Visit the ARCUS PolarTREC website for more information: http://www.polartrec.com/

Comments (1) Sep 16 2011

Katey Walter Anthony (UAF) smiles after a good day of field work. Photo: Valera Fedoseev

In terms of carbon footprint, though one hears a lot about carbon dioxide, it’s methane that wears the size 12 clodhopper. Methane is more effective at trapping heat in earth’s atmosphere than carbon dioxide and also contributes to the degradation of the ozone layer. When permafrost thaws, release of methane into the atmosphere from anaerobic decomposition contributes to climate warming, which subsequently causes more permafrost thaw – thus acting as an important feedback loop in global climate. Katey Walter Anthony (University of Alaska, Fairbanks) and an international team of colleagues are studying permafrost and thermokarst lakes to better understand how thawing permafrost and the subsequent release of methane is contributing to climate warming. Since 2008 Anthony and colleagues have worked on the interdisciplinary study in Cherskii and Yakutsk, Russia, all over Alaska, in western Canada, Greenland and Sweden describing the distribution of permafrost and the process of landscape evolution and gas escape as permafrost thaws.

“We have a pan-Arctic focus with the goal of understanding carbon release from permafrost. Not only are we describing the extent of thermokarst in Siberia, Alaska, western Canada and other regions of the Arctic, we’re looking at how thermokarst lakes develop and release methane in particular,” says Anthony.

Permafrost, soil at or below the freezing point of water for at least two years, is common at high latitudes. As the climate warms, however, permafrost thaws and forms an irregular landscape called thermokarst (the pitted nature of the surface resembles those developed in karst areas of limestone). In surface depressions, lakes form where massive ground ice melted. Permafrost contains vast reserves of carbon stored within a frozen framework that is released when permafrost thaws.

Anthony and colleagues are interested in yedoma, a specific type of permafrost that is particularly high in carbon and supersaturated with ice, about 50-90% by volume. Formed in unglaciated continental areas during the last ice age, yedoma is most prevalent in northeastern Siberia where it may be tens of meters thick. Thawing yedoma yields a significant source of atmospheric methane.

“Thermokarst lakes formed from the thawing of yedoma are very efficient at releasing carbon, in the form of methane, into the atmosphere,” Anthony explains. “As the ice melts, water and 46,000 year-old methane, CH₄, are released. We are trying to quantify how much carbon is released as well as the variability in different regions.”

When headed to the field, Anthony and her co-investigator, Guido Grosse, first identify likely areas of permafrost exposures using satellite imagery. Ideal locations are usually along rivers where cut banks have excavated steep exposures that may be up to 50 m tall.

Researchers survey permafrost-laden soils at the Arctic Coast north of Cherskii, Northeast Siberia. Soils rich in ground ice also have high organic matter content. When this permafrost thaws, formerly frozen carbon becomes available which produce carbon dioxide and methane. Photo: G. Grosse

“These are the best places to work because we can see 60,000 years of history all at once. You can see the whole layered cake of ice and frozen soil in cross section! We can tease out a lot of information about past permafrost and climate,” Anthony says. “We have to be very careful when we sample to find a fresh cut that has not thawed in the recent past. The first part is just moving dirt with shovels and scrapers so we have to be very careful. We have to work quickly because the permafrost can thaw very quickly. We sample and describe different units with a focus on the amount of ice and carbon in representative layers. We can scale up. Studying broad exposures has some big advantages over permafrost coring, where our interpretation of an area is otherwise limited to what we find in 4cm diameter cores.”

Anthony does much of her methane field work during winter. And, while she says it’s no fun to wake up in -30 degree temperatures at field camps, winter work is easier in some ways. Lake ice provides an opportunity to map methane bubbles on thermokarst lakes. Coring permafrost requires the use of a permafrost drill, a gas-powered auger with a core barrel and drill bit at the end. Anthony says permafrost coring is often most easily accomplished in winter conditions when the permafrost is frozen solid. Samples can be quickly acquired from a snowmobile and there’s less chance of the core casing freezing up during the coring since it’s already cold.

Anthony and then graduate adviser, Terry Chapin (UAF), engage in a tug of war to separate a tube containing lake sediments from the core head. Photo: M. Chapin

Anthony’s team also prefers coring thermokarst lake sediments in the winter because they can use lake ice as a stable platform for field work. Sediments from the bottom of a lake can tell Anthony how old the lake is–some lakes developed at the end of the last ice age nearly 12,000 years ago, while others developed much later and have been expanding since.

Sometimes lake coring in summer is necessary. “Summer lake coring requires a huge amount of work. It’s very dirty. There are lots of mosquitoes. I have spent hours hammering a core barrel into the lake bed from a raft just to have nothing come up. It’s much easier in the winter when we can do it from the ice covering the lake. Then it requires much less gear and it’s stable,” says Anthony.

Methane bubbles rising from the lake bottom are trapped by winter ice. Photo: K. Walter Anthony

Anthony also maps lake methane bubbles during winter. Methane formed by microbes from thawing permafrost is released from lake bottoms in the form of bubbles all year long. In summer, bubbles rise to the top of the lake and burst, releasing almost pure methane into the atmosphere, but in the winter, lake ice forms a lid that traps methane bubbles.

“We use shovels to remove any fresh snow from the lake ice surface. What we find is really neat–the ice looks black and had beautiful white bubbles stacked on top of each other in place to place–much like the stars scattered across the night sky,” Anthony explains. “We map the distribution of the bubbles which get trapped, forming tall columns of methane. We can tell where the gas is coming from, how it clusters. We get a good spatial data set.”

Anthony and Dragos Vas (UAF) check the volume of gas collected in under-ice bubble traps on a thermokarst lake in Fairbanks. Photo: M. Grimes

Back in the lab Anthony sub-samples permafrost and lake cores for radiocarbon dates, a method that helps her and colleagues understand the history of permafrost formation across northern Siberia and Alaska.

In 2011, Anthony’s team, along with students and post doctoral candidates from the University of Alaska, Fairbanks, returned to Seward Peninsula and interior Alaska field sites to recover time-lapse cameras, temperature data loggers, and bubble traps, which record the rate of gas release. The team also worked in Cherskii, Russia. During that expedition, Anthony worked with three students and a postdoc who have sub-projects studying permafrost and peat along the Kolyma River.—Marcy Davis

Katey Walter Anthony’s research is funded, in part, by NSF, NASA, and the Department of Energy

Comments (0) Sep 08 2011

Act I of NSF’s Greenland Research  Season

Clément Miège and Evan Burgess arrive in Kangerlussuaq. Photo: Byrd Polar Research Center, OSU

Like spring flowers, science teams funded by the U.S. National Science Foundation are popping up all over the Arctic as we head into the research season. CPS staff recently began our March/April migration to Kangerlussuaq, the program’s logistics hub in Greenland.  In addition to opening our office and warehouse spaces and preparing for the influx of research teams coming later this month, we assisted an early bird Arctic Circle Traverse (ACT) team going in to the field for Principal Investigators Rick Forster (U of Utah) and Jason Box (Ohio State U).

The ACT research aims to improve our understanding of the Greenland ice sheet’s mass balance by providing data on how much snow accumulates in areas where little information exists now.  Scientists can tell us about the ice sheet’s mass balance by measuring how much snow and ice is lost through melting (a lot these days) and comparing it to how much is gained through precipitation.

Loading ice core boxes in the Twin Otter. Photo: Polar Field Services

The Forster/Box team of four—researchers Evan Burgess and Clément Miège (U of Utah), driller Terry Gacke and mountaineer Brian Ballard—flew to Raven Camp out on the ice sheet and mounted a ~350-mile snowmachine traverse from there a few days ago. Each day the team rides the ice sheet, towing a ground-penetrating radar on a sled that collects information on snow accumulation in the top 50 meters of the ice sheet. They also stop to drill ice cores that help them verify the radar data. They leave the cores in boxes for later retrieval and shipment to U.S. research labs for analysis.

As we’ve said many times, polar field work is not for the faint-of-heart. The ACT team is camping out on the ice sheet.  In tents.  In temperatures that fall into the minus 30s and 40s at night. Strong winds pinned them at kilometer marker 48 yesterday, but the forecast suggests they can get an early start tomorrow and make tracks before a new storm arrives. We keep a close eye on them, through daily check-ins and “bread crumb” GPS tracking devices affixed to their snowmachines that tell us exactly where they are in real time. You can keep an eye on them too. Visit:  http://www.datatransport.org/act/monitor to view the tracker.  And visit the Ohio State University ACT page at: http://bprc.osu.edu/wiki/ACT to keep up on the team’s activities via their online journal.–Kip Rithner

Comments (0) Apr 08 2011

Melt lakes on Greenland's ice sheet. Photo: Ed Stockard (http://www.flickr.com/photos/coastaleddy/)

Click this link to watch a short movie.

This movie, produced by the Cryospheric Processes Laboratory, consists of stills and video collected during 2009 and 2010. Meltwater is the theme. The vocal is a Shaman Inuit Chant.

Greenland experienced a record amount of melting in 2010.

New records were set during the year for surface melting, runoff of water, the number of days when bare ice was exposed due to melting snow, and the decrease in the total mass of Greenland’s ice sheets, according to a paper published recently in Environment Research Letters.

NOAA is also out with its annual Arctic report card for 2010, which among other things summarizes what was observed in Greenland this past year:

Greenland climate in 2010 is marked by record-setting high air temperatures, ice loss by melting, and marine-terminating glacier area loss. Summer seasonal average (June-August) air temperatures around Greenland were 0.6 to 2.4°C above the 1971-2000 baseline and were highest in the west. A combination of a warm and dry 2009-2010 winter and the very warm summer resulted in the highest melt rate since at least 1958 and an area and duration of ice sheet melting that was above any previous year on record since at least 1978. The largest recorded glacier area loss observed in Greenland occurred this summer at Petermann Glacier, where 290 km2 of ice broke away. The rate of area loss in marine-terminating glaciers this year (419 km2) was 3.4 times that of the previous 8 years, when regular observations are available. There is now clear evidence that the ice area loss rate of the past decade (averaging 120 km2/year) is greater than loss rates pre-2000.

Comments (0) Jan 30 2011

PolarTREC teacher Jim Pottinger does the hokey-pokey at Summit Station. All photos: Jim Pottinger

“Sleeping in a tent in the Arctic was a new experience for me. Temperatures dipped below 0°F and the winds were consistently blowing against the tent.”– Jim Pottinger, 2010 PolarTREC teacher

Jim Pottinger enjoys cold weather, so living at Summit Station’s Tent City on the Greenland ice cap for a week was fine by him. Camping atop 3200 meters of ice was one of several new experiences for the Pennsylvania native who travelled to Greenland last summer as part of the PolarTREC Program. Pottinger’s team, which is led by PI Konrad Steffen (CIRES), travelled to Summit to maintain instrumentation for the NSF-funded BSRN – Compatible Irradiance Measurements and the Stable Boundary Layer

At Summit Station, Pottinger worked with Karl Schroff and Hansjoerg Frei (from the Swiss Federal Institute of Technology) and Nikko Bayou (UC Boulder).

After a long day of shoveling snow Nikko Bayou reaches the APTU at last.

Their first task was to locate and retrieve an Automated Temperature Profiling Unit (APTU), which started its mission recording high altitude weather data in 2007.

“After a four-mile bone-chilling [snowmobile] ride, we arrived at the site. It was a beautiful location in the middle of the Greenland ice sheet. The sky was blue, the terrain was white and there was nothing as far as the eye could see,” Pottinger wrote in his August 14 journal.

They located the unit by GPS. Only two feet of the ten-foot tall APTU tripod was sticking up out of the snow. It took six hours and digging down about twenty feet before they freed the tripod and data logger using snowmobiles and ropes.

Elevating the Automatic Weather Station - turns out it looks tougher than it is.

The team’s next task was to elevate Summit’s AWS, one of eighteen such stations in Greenland. First, the scientists attached cable extensions to accommodate the station’s new height. Next, they erected a tripod over the station, attached a rope to the top of the AWS, and lifted the station ten feet while inserting an extension tube to the base. Once the station was secure, they removed the tripod and later verified data transmission. The entire data transmission process only took one hour!

Next, they dug a 140-centimeter deep snow pit next to the AWS. Pottinger recorded the pit’s snow structure, making notes of density, snow crystal shape and size, layer thickness and volume  every ten centimeters. These measurements will help ground-truth the AWS and ensure that sensors were working properly over the two previous years.

Pottinger becomes an old hand at snow pit measurements.

Pottinger also assisted in elevating and calibrating BSRN instrumentation and learned about ongoing NOAA weather experiments.

Pottinger’s visit coincided with Summit’s transition between seasonal crews. This meant a busy couple of days while winter preparations were made. Following a great end of season dinner, Pottinger spent his last night in the Big House and flew out with a jubilant summer crew the next morning.

Summer crew kicks back at the end of the season party at Lake Fergueson.

Pottinger, who has a background in geology, coordinates the GATE (Gifted and Talented Education) program at Gateway High School in Monroeville, Pennsylvania. He acts as an academic advisor, making sure students are on an academic path consistent with their post-secondary goals, and as a science teacher, giving periodic guest lectures in science classes.

Pottinger hopes to return to Greenland’s Swiss Camp next May with Steffen. He will again be involved in systems maintenance and hopes to learn more about how the collected data is being used in various science projects. In the meantime, he’s keeping busy sharing his experience with students, teachers and community. Pottinger hopes he can begin to correct some of the misconceptions people have about climate change, the Arctic, and the people who live there.—Marcy Davis

Comments (0) Jan 20 2011

Last week the National Oceanic and Atmospheric Administration (NOAA) issued its 2010 Arctic Report Card, which reported that so far this year Greenland has experienced record-setting high air temperatures, ice loss, and marine-terminating glacier area loss. Summer seasonal average (June-August) air temperatures around Greenland were 0.6 to 2.4°C above the 1971-2000 baseline, and temperatures were highest in the western part of the country.

The hot summer followed a warm and dry winter, resulting in the highest melt rate since at least 1958. The area and duration of ice sheet melting was higher than any previous year on record since at least 1978.

Scientists observed large glacier area loss, particularly at the Petermann Glacier, where 290 km² of ice broke away. The rate of area loss in marine-terminating glaciers this year (419 km²) was 3.4 times that of the previous 8 years, when regular observations are available. There is now clear evidence that the ice area loss rate of the past decade (averaging 120 km²/year) is greater than loss rates pre-2000.

CH2M HILL Polar Services supports much of the science and research that contributed to the Arctic Report Card.  —Rachel Walker

Comments (0) Oct 25 2010

From hat tricks to the Helheim glacier—a young David Holland spent much of his childhood on ice before studying the matter full time. Photo: Denise Holland

Addicted to Ice

Growing up in Newfoundland and Labrador, Canada, meant David Holland was well acquainted with ice in nearly every form from a young age. Years later, as a mathematics professor at New York University (NYU) and director of the university’s Center for Atmosphere Ocean Science he’s still surrounded by ice.

Now, his days are spent traveling the world studying ice-ocean interactions and developing computer models that explain how the world’s ice and oceans may fare in a changing climate.

“In the late 1990s, it was noticed that glaciers change a lot faster than people thought—they were much more dynamic. My background is in ocean science, so I was curious about this speed up and the ocean’s contributions,” Holland said. “So I became interested in studying and modeling this. I guess you can say I’m addicted to ice in a lot of ways,” he laughed.

Studying Ice Around The World

David Holland’s love of studying and modeling ice has taken him from the top of the planet to the bottom, and lots of places in between. Here he is all smiles in Antarctica. Photo: Denise Holland

Holland’s fascination with ice has led to some interesting jobs throughout his career and has taken him on adventures spanning the globe.

While still in Newfoundland, he worked as a research engineer to determine ways to move icebergs in order to prevent collisions with ships.

“This technology really never panned out. In Newfoundland and Labrador and Greenland there are icebergs all over the place. We tried to blow them up, cut them in half and melt them, and what not. Really large icebergs are a challenge to move and really the easiest thing is to just get out of their way,” Holland explained.

South Of The Equator

After leaving Canada, Holland headed 10,000 miles south to Australia for a postdoctorate fellowship at the Australia Bureau of Meteorology. While there he worked on coupled modeling—pairing global ocean models with atmospheric models. It was an exciting time because he worked with a group of modelers who had just started to include sea ice in global climate models.

“As we were doing that in the 1990s, nobody had the vaguest thought sea ice in the Arctic would change the way it has today. We now know in the summer sea ice reaches half the extent it used to. That was something no one even remotely believed in the 1990s. Today those models still work pretty well, but they aren’t good enough to project the kind of sea ice behavior we’re actually observing,” he said.

Launching Career

After finishing his postdoctoral work in Australia and the United Kingdom, Holland was a research scientist at Columbia University’s Lamont-Doherty Earth Observatory. In 1998, he joined NYU as a professor where he lectures, develops computer models and plans research missions. His most recent mission supports an ongoing National Science Foundation-funded project in Greenland.

Field Work in Greenland

David Holland (far right), Denise Holland, and graduate student Carl Gladish pose at the calving front of the Helheim glacier during this summer’s field effort in the fjords of Greenland. Photo: Denise Holland

This July and August Holland was busy studying ocean and ice sheet interactions at the Ilulissat and Helheim glaciers in the fjords of Greenland. The work is part of a five-year (2009-2013) effort to improve the understanding of how warm, deep ocean waters are influencing ice sheet retreat.

Holland and a team of graduate students recorded meteorological observations and collected water temperature, salinity, oxygen, suspended sediment and current measurements using CTDs.

In sea-ice-covered areas, the team used a helicopter to first break up the sea ice before lowering an expendable CTD (XCTD) into the water column. An XCTD is an expendable probe that can be dropped from moving ships or aircraft. Data from the probe are transmitted by wire. For areas with less sea ice, the samples were collected by ship using a traditional CTD lowered off the side of the ship by winch.

Help From The Locals

This bearded seal may not realize it, but it’s playing a critical role in helping scientists study ice-ocean interactions. This summer, David Holland and colleagues attached CTDs with transmitters to the backs of two seals in Greenland. The CTDs will collect data as the animals swim through the water. The devices will fall off after 12 months when the seals molt. Photo: Aqqalu Rosing-Asvid

Holland also looked to the local population of seals to help collect water column data in the fjords. He attached small CTDs with telephone transmitters on the backs of two seals. “I have two seals swimming around now and they email me every four or five hours with profile temperatures and salinity. Then I can look at a map and see where they are,” he said.

The CTDs will stay on for roughly 12 months and will fall off when the seals molt in the spring. Holland points out that every effort was made to meet animal welfare guidelines and ensure that no harm comes to the animals as a result of the CTD attachment.

Water column data collected by both humans and seals alike will be combined with the meteorological observations and used to develop a coupled ocean-ice sheet model. Ultimately, the data and the resulting model will help researchers quantify how the water from the melting ice sheet may change global sea level in the future.

Climate and Future Modeling

In the future, Holland plans to tackle a very tricky climate-related question: which changes in climate are occurring naturally and which are influenced by human activities? He will collaborate with others to make long-term observations in both Greenland and Antarctica to try to answer these questions.

He also hopes to develop models that will give us a better idea of how sea level may change in the future. “It’s going to take a long time to get that sorted out correctly, if at all, but the climate model may tell us about future sea level changes due to glaciers,” Holland said.

A Family Affair

Month-long trips in remote areas like Greenland require a tremendous amount of effort and teamwork. Data collection success is dependent on detailed planning done months in advance. And Holland’s wife Denise is always more than happy to lend a helping hand by taking on much of the logistics planning and coordination.

Denise is also an artist currently studying at NYU. She often joins him in the field to document the trips through photos and videos. “The trips take about a month or so and it’s nice to have family around to help,” Holland said.

Holland’s graduate students also play a critical role in the success of the missions. In addition to teaching two graduate-level courses, he always takes graduate students on missions to help with data collection and to gain valuable field research experience.

“It’s [field work] extremely valuable both to me and to them. The graduate students are very, very, capable, hard working and creative about coming up with solutions. It’s an all-around victory,” he said.

To learn more about David Holland and his ice-ocean interaction research, visit: http://efdl.cims.nyu.edu/ —Alicia Clarke

Comments (1) Oct 12 2010

The slip of water separating Greenland's northwestern coast from Canada's Ellesmere Island is called the Nares Strait. The giant iceberg that calved from Greenland's Petermann Glacier in August has broken in two and entered the strait. Map courtesy Arctic Portal (http://www.arcticportal.org/)

The enormous iceberg that calved off Greenland’s Petermann Glacier Aug. 4 has split in two during its trip through the Nares Strait. Andreas Muenchow, an associate professor at the University of Delaware who has been tracking the berg via satellite images, told CNN that it broke after repeatedly running into a small rocky island called Joe Island west of Greenland. 

“The forces of the ocean currents and the winds wiggling it on and off the island were too much,” Muenchow said.

The larger piece is about 152 square kilometers (59 square miles) or roughly 2.5 times the size of Manhattan. The smaller piece is about 84 kilometers (32 square miles). Muenchow and colleagues looked at historical records dating back to 1876 and determined that the original berg was the biggest to have calved off Petermann in that time.

Image courtesy Andreas Muenchow, University of Delaware

The iceberg entered the Nares Strait, which runs between Greenland and Ellesmere Island, at the beginning of the month. A European Space Agency satellite captured its progress and the agency created this animation of the berg’s travels:

Petermann Glacier iceberg progress toward Nares Strait

Meanwhile, Ohio State University Professor Jason Box has been thwarted in his attempts to reach the glacier to retrieve data from instruments he left last year at the site of the break. These include two time-lapse cameras that should have recorded the calving event.

He raced off last month to Greenland with colleagues in hopes of reaching the glacier and equipment. But the group was unable to arrange for a safe helicopter flight to the remote location and Box has returned home.

“Needless to say, it was difficult to turn south without the data,” he wrote Monday on his blog.  He’s hoping that a flight can be arranged for one of his colleagues before mid-October when daylight becomes too scarce for such a long trip. If that proves impossible, they’ll plan on a trip in March, he said.

­­– Emily Stone

Comments (0) Sep 14 2010

An artist's rendering of the ICESat satellite. Credit: NASA

NASA’s Ice, Cloud and land Elevation satellite (ICESat), which for seven years gathered data about ice sheets and sea ice at Earth’s poles, was guided out of orbit and plunged into the Barents Sea on Aug. 30, the agency reported.

NASA launched ICESat in January 2003 as the first mission dedicated to specifically studying the polar regions using a space-based laser altimeter. It was intended to transmit data for only five years.  However, ICESat’s lasers lasted until February. Flight controllers started lowering its orbit in June until it reached 200 km (125 miles) above the Earth. At that point, its orbit naturally lowered until it mostly burned up on re-entry into the Earth’s atmosphere with the few remaining chunks landing in the Barents Sea.

The satellite has helped scientists better measure changes in the mass of the ice sheets in Antarctica and Greenland, sea ice thickness at both poles, vegetation height and the height of clouds and aerosols. In the Arctic, for example, researchers used ICESat to watch as thin, seasonal sea ice replaced thick, older sea ice. In Antarctica, scientists were able to identify the network of lakes underneath the ice sheet that actively drain or fill.

“ICESat has been a tremendous scientific success,” said Jay Zwally, ICESat’s project scientist at NASA’s Goddard Space Flight Center, in a statement on NASA’s website.  “It has provided detailed information on how the Earth’s polar ice masses are changing with climate warming, as needed for government policy decisions.”

NASA has begun designing ICESat-2, which it intends to launch in late 2015. In the meantime, the agency’s Operation Ice Bridge has been underway since last year to bridge the gap in polar data in between ICESat missions. Operation Ice Bridge uses NASA aircraft to target areas of rapid change at either pole to get 3-D views of ice sheets, ice shelves and sea ice. It’s the largest ever aircraft-based survey of Earth’s polar ice.

– Emily Stone

Comments (0) Sep 01 2010