Burning Questions

May 17, 2010

Scientists Seek Information from the Anaktuvuk River Fire

By Emily Stone

Journalists visited the site of the Anaktuvuk River Fire last summer. The charred tussocks were still visible beneath the blooming cottongrass. Photo: Lisa Jarvis

Gaius Shaver has been traveling to Toolik Field Station for 34 summers to study how tundra ecosystems react to small environmental changes. One of his experiments involves building greenhouses over 8-by-16 foot plots of land to gauge how plants react to warmer soil.

His research has yielded interesting results over the years, but there’s always been a question of how well that data would translate over large tracks of land.

Suddenly, Mother Nature gave Shaver and many other Toolik scientists a way to find out.

A massive fire burned about 400 square miles of tundra along the Anaktuvuk River from July to October 2007. It was the largest tundra fire ever recorded on Alaska’s North Slope. Now the scientists are studying how the area, which is roughly the size of Cape Cod, responds. In addition to examining the warming soil and plant changes, the group is looking at how much carbon was lost in the fire, the ongoing exchange of carbon between the land and air, and how melting permafrost is affecting rivers and streams. They’re finding that the fire has had a significant impact in all these areas. And given that continued warming in the Arctic will likely lead to more lightning which will lead to more fires, these are important questions to answer.

The 2007 Anaktuvuk River Fire burned a Cape Cod-sized section of the North Slope. Scientists are interested in how long it will take the area's plants and soil to recover. Photo: Adrian Rocha

“There’s a lot going on,” said Shaver, a senior scientist at the Marine Biological Laboratory who is leading the National Science Foundation-funded, three-year study that includes nine senior collaborators and a couple dozen other researchers. “It’s very exciting.”

The group calculated that the fire burned more than two million tons of carbon that had been stored in the soil, or roughly 25 years worth. This equals about 10 percent of the annual carbon emissions for the city of Boston. The fire also burned between 300 and 1,000 years worth of nitrogen.

The group is also interested in the continued changes in carbon exchange between the soil and atmosphere. Using instruments set up on three towers in the burn site, they’re measuring the exchange of carbon during the summers. If plants photosynthesize more than they and the soils in which they grow respire, then the net result is carbon being removed from the atmosphere. If there’s more respiration than photosynthesis, then the opposite is true.

Overall, the burned areas have a net carbon loss from the soil, meaning more carbon is being released into the atmosphere than at unburned spots. The researchers calculated that in 2008, the fire accounted for a minimum 2.8 percent reduction in the amount of carbon being taken out of the atmosphere across the North Slope even though the Anaktuvuk River Burn accounts for only 0.55 percent of the North Slope’s area.

The researchers know from older fires and erosion scars that shrubs tend to dominate the landscape after a disturbance at the expense of mounds of tussock grasses, which cover much of the North Slope. This seems to be playing out at the Anaktuvuk River Burn. Although shrubs were knocked back dramatically by the fire — even more than the tussocks — they are recovering rapidly even in severely burned areas and may soon exceed the grasses in the amount of ground they cover. 

Undisturbed tundra tends to keep its plants in pretty consistent ratios as they compete for limited resources in the soil. “A disturbance shakes up those relationships among species,” Shaver said. This is important because shrubs tend to insulate the soil in the winter, keeping it warmer, and also hold less carbon below ground than tussocks do, both of which can further change the landscape.

Another striking discovery is the change in albedo, meaning the percent of the sun’s radiation that is reflected away from the ground. In the first summer after the fire unburned portions of the burn site had a 17 percent albedo while severely burned sections had a 3.5 to 4 percent albedo. That means an additional 13 percent of the sun’s radiation was being absorbed in those areas. And that heat has to go somewhere, often warming the soil to higher temperatures and permeating deeper than normal. This difference was less in 2009 than in 2008, and Shaver said it will eventually return to the level of unburned tundra. 

Data show that burn scars absorb more of the sun's radiation than unburned tundra, increasing soil temperatures. Photo: Adrian Rocha

In the meantime, increased heat flux into the ground can cause thermokarst failures, which occur when the ice that’s normally frozen solid in permafrost melts and the land above it collapses like a soufflé. Last summer the group noticed more and more of these depressions as the season continued. When thermokarst erosion happens near streams and lakes, it dumps extra nutrients into the water, giving microbes, plants and fish access to more food and thus changing the aquatic ecosystems. 

“We can’t make a treaty to stop thermokarst and fires,” said Syndonia Bret-Harte, an associate professor at the University of Alaska Fairbanks, who is heading up the plant studies at the burn.

Bret-Harte, who is also Toolik’s associate science director, was at the station in 2007 while the fire was burning about 25 miles away and at times could see a wall of smoke in the distance.

“It was awesome and beautiful, but disturbing at the same time,” she said.

Once the scientists realized how big the fire was, Shaver applied for an NSF grant for the following summer, knowing how valuable the natural experiment would be for the scientists at Toolik, many of whom are part of an ongoing Long Term Ecological Research Project, one of 26 in the U.S. LTER network.

The group is adding a component to this summer’s research by visiting the sites of two large fires from 1993 to see how they’re recovering in hopes of predicting how the Anaktuvuk River Burn will fare in the coming years. They’ll take measurements to see, for example, how much soil has accumulated above the char level and what the diversity of plant species is like.

All of this is crucial information to have as more and more disturbances like lightning-driven fires and thermokarst occur across the Arctic.

“Overall climate change is gradual and the overall response to this change is gradual,” Shaver said. “But then we have these patches of intense change and the patches may be changing so intensely that from the perspective of the whole North Slope, they actually dominate the overall changes.”

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Of Course! The Thing!

May 17, 2010

Congratulations and a $15 iTunes gift card to Kelly Brunt, post-doc at the Institute of Geophysics and Planetary Physics at Scripps Institution of Oceanography. Kelly was the first to point out that Brad Stefano’s photo (shown below) is evocative of the campy horror classic.

Thanks for playing!

Summer staff arrive at Summit in early April. Photo: Brad Stefano


To Inuit, Sea Ice Means “Freedom”

May 13, 2010

  

At the edge of the sea ice, a Barrow resident awaits the return of a seal-skin whaling boat. Photo: Faustine Mercer

Here’s a really interesting story on Shari Gearheard’s NSF-funded people and sea-ice study. Gearheard, a glaciologist from U Colorado’s National Snow and Ice Data Center, combined scientific sea-ice studies with the traditional knowledge of Inuit collaboraters who’ve spent their lives on or near the ice.  The aim: to gain a better understanding of how sea ice is changing in the Arctic–and how community lifeways around the Arctic may be changing in response.  

Gearheard and her collaborators speak extensively in the piece, and what they have to say about the changes they’ve seen in sea-ice conditions is compelling.   

“‘I’m a scientist so when I look at sea ice I see what its properties are. How dense it is. But I remember sitting with the hunters when we were all in Qaanaaq. They looked at the sea ice and the first thing they said they saw was ‘freedom’.  

‘(Sea ice) meant they could hunt for food. It meant they could travel to see relatives on the other side of the water, that they hadn’t seen all year.  

‘That was a very powerful thing for me as a person, not just as a scientist.'”–Shari Gearheard  

* * *

“‘When I was a boy, the ice used to hover around Barrow all year,’ 51-year-old Leavitt said. ‘Now when the ice takes off it doesn’t want to come back. So our hunting is very limited.'”–Joe Leavitt, Barrow resident and whaling captain  

* * *

“‘We used to live as nomads in those days,” Sanguya continued. “After Christmas, when there was enough snow, we’d go out on the sea ice and make igloos.  

‘In those days I didn’t have any math or measurements … or anything like that. But I remember looking down through seal breathing holes and the ice was so thick, they looked like they were tapering away.  

‘Today you don’t see that very much. You’ll probably see 4 feet or 5 feet (down) and that’s it.'”–Joelie Sanguya, Elder and hunter, Clyde River, Nunavut

Hunters in Qaanaaq, Greenland traditionally travel over the sea ice on dog-powered sledges like these. Photo: Hans Jensen


All Photos by Swing Boss!

May 11, 2010

Willow Fitzgerald pulls up at the GrIT camp in the Tucker.

Robin Davies hops out of the Tucker. We can't say who took this photo, but it wasn't Robin.

Flashback to last week, during the storm.  Remember how Robin Davies and Willow Fitzgerald drove Allan Delaney the 70 miles back down to Thule Air Base last week in the Tucker in the storm?  Allan was to be extracted from the traverse via helicopter, but of course weather fouled that plan and so the team reverted to Plan B, an overland return–remember?So Robin and Willow were pinned in Thule overnight as the storm raged on. They managed to avoid a second overnight at the base when they scooted out of town during a momentary break in the weather. Up on the ice sheet, the storm continued, but the two were able to navigate using the Garmen 695 GPS units NSF purchased for moments just like these. 

We don’t have any pictures of this portion of the adventure because Robin forgot to bring his camera with him–an uncharacteristic moment of forgetfulness for the GrIT photographer. But all’s well that ends well, because the Swing Boss was ready with Robin’s camera when the heroes returned. He took all of the pictures in this post. Who is he? Ask the Swing Boss. 

Nice weather. The Tucker arrives at the GrIT camp.

The Greenland Inland Traverse is funded by the National Science Foundation (NSF). CH2M HILL Polar Services and Cold Regions Research and Engineering Laboratories are working together with the NSF to develop the traverse infrastructure and route. The 2010 spring traverse has several foci: find a safe overland route to Summit Station to help reduce logistical costs and environmental impacts of conducting research there; provide a research platform for scientists conducting field work in Greenland; optimize mobility by focusing on the sled/snow interface.  For more field notes coverage of GrIT, click hereGrIT contact: 

Allen Cornelison, Polar Field Services, CH2M HILL Polar Services
GrIT project manager
allen at polarfield.com

GoNorth!+GrIT=GrITGo’N!

May 10, 2010
Two Become One
All Photos: Robin Davies

Some gorgeous and well-mannered Polar Huskies wait for the humans to transfer the GoNorth! load to GrIT.

Adapt or fail: this may be the first rule of successful polar exploration, as countless stories from the age of the great adventurers (and from our own research clients) will attest. Over the weekend, while many of us celebrated Mother’s Day, there was a marriage of sorts on the Greenland ice sheet. The two traverse teams we’ve been following—GoNorth!’s Polar Husky-powered education effort, and GrIT’s tractor-towed operational effort—combined forces to get everyone back on schedule after last week’s stormy weather delayed progress.  

Mille Porsild, dog handler-in-chief, settles the canine team atop some GrIT cargo totes. Mille prefers to ride up on the totes with her pack, though there's room for her in the warm camping wannigan.

NEEM is the North Eemian drilling camp, an international research collaboration whose main goal is to harvest an ice core (for climate studies) that reaches all the way through the ice sheet. While the University of Copenhagen has overall management of NEEM and operates the camp, the National Science Foundation supports U.S. researchers (U Colorado’s Jim White leads this effort) and provides the heavy air lift as well. Air National Guard LC-130 planes fly between Kangerlussuaq and NEEM every ten days to two weeks—weather permitting, of course.  

So if the three miss this flight, they could be auxiliary NEEM staff for two weeks waiting for the next flight—an unhappy possibility given teaching and research commitments. (Some of us would pay good money to be stranded at the storied NEEM camp for a week or so with the likes of Danish polar research legends like Dorthe Dahl-Jensen and JP Steffensen, but that’s a tale for another post.)  

“With the loads reconfigured (once they passed through the crevassed zone with its steep inclines), the GrIT is moving forward at a decent clip. The goal is to make at least 40 miles per day,” Allen explained. “Over the past few days, they have been achieving their goal even with some soft snow.”  

Settled down and ready to make tracks.

While GrIT machines can continue plowing ahead in most storm conditions, the GoNorth! dogs, though incredibly strong and courageous, must at some point hunker down and wait for the worst weather to clear–they are not made of metal. The risk that the GoNorth! team might be delayed again by a good blow was considered too great, and so all have joined the GrIT traverse. That’s an additional 23 dogs, four people, sleds and gear.  

In short, a parade.  

  

“With firm snow, the Case has been able to hold 6th gear with little slippage,” Cornelison continued. “Ruts are between four and six inches. The Tucker has been holding second gear and keeping up with the Case though towing multiple sleds and the 3,000-gallon fuel bladder, which they have been fueling from. I believe that the Tucker load is about 120 feet long now.”  

“The weather has been cooperating nicely with unlimited visibility, sunny skies, light winds and temperatures between -4 and +10F.”  

“The teams camped Sunday night 110 miles from NEEM. They should arrive at NEEM mid-day on the 12th.”   

 
 
 
 

Robin writes, "The Case has a Greenlandic name, Qimuttuuaraq. It's a name that's often given to a small dog that pulls hard for its weight. A rough translation would be 'Small dog with big heart'." We think the same could be said of all souls on the traverse, four- and two-legged alike.

The Greenland Inland Traverse is funded by the National Science Foundation (NSF). CH2M HILL Polar Services and Cold Regions Research and Engineering Laboratories are working together with the NSF to develop the traverse infrastructure and route. The 2010 spring traverse has several foci: find a safe overland route to Summit Station to help reduce logistical costs and environmental impacts of conducting research there; provide a research platform for scientists conducting field work in Greenland; optimize mobility by focusing on the sled/snow interface.  For more field notes coverage of GrIT, click here 

GrIT contact:
Allen Cornelison, Polar Field Services, CH2M HILL Polar Services
GrIT project manager
allen at polarfield.com

 


Delivering Boardwalk

May 10, 2010

PFSers Larry Gullingsrud and Annelisa Neely deliver boardwalk to Mike Weintraub's tundra plots at Imnavait Creek. Researchers will use the dark material in the background to artificially warm some of the tundra plots. Photo: Jason Neely

University of Toledo’s Mike Weintraub returned to Imnavait Creek near Toolik Field Station last week for the first full season of tundra plot studies supported by his recent NSF grant.  The project is one of a group of new research to be fielded at/near Toolik this year to study changing seasonality in the Arctic (CSAS).  Specifically, Weintraub’s team is looking at how altered timing of seasonal events—earlier spring thaw and later fall freeze, for example—may affect nitrogen cycling in the soil, and how that in turn impacts tundra plant and microbe growth.

Polar Field Services staff returned to Toolik in late April for spring science support and station facilities projects. Among the larger science efforts, Jason Neely’s team placed about 3000 linear feet of boardwalk out on Imnavait Creek tundra manipulation plots for Weintraub’s CSAS soil nutrient experiment.   The boardwalk protects the fragile, slow-growing tundra from the many footsteps of researchers visiting the plots to collect plants, data and/or to manipulate the conditions.  The Weintraub team will continue working on the CSAS project for the length of the summer season at Toolik Field Station, departing in late August.

Weintraub heads an interdisciplinary collaboration composed of four other PIs:  Paddy Sullivan (U Alaska), Josh Schimel (U California), Edward Rastetter (Marine Biological Laboratory), and Heidi Steltzer (Colorado State U).

Researchers will manipulate the timing of seasonally driven processes in tussock tundra ecosystems by advancing the timing of snowmelt with radiation-absorbing fabric placed over the snowpack in the late spring and by using open-top warming chambers in concert with advanced snowmelt. They will follow how seasonally driven plant and soil dynamics are affected by changes in the timing of snowmelt and warming.


GrIT: Circumzenithal Arc

May 7, 2010

Parahelia with circumzenithal arc. Greenland ice sheet, May 6, 2010. Photo: Robin Davies

From Robin’s email:

“I got this shot yesterday afternoon, as we reconfigured the Tucker load (which is why the outhouse is in the frame). As the cloud thinned and the sky got bluer, the sun halo and sun dogs that had been coming and going for some time  suddenly developed a Circumzenithal Arc (the inverted rainbow above the sun), which sent me scrambling for my camera.

“I’ve been trying to get a good shot of one of these ever since I’ve been coming to Greenland and now I’ve got one with an outhouse in it!”