The Ablation Zone: Where Ice Goes to Die: Understanding Drainage Efficiency of the Greenland Ice Sheet Ablation Zone

July 6th, 2016 by Lincoln Pitcher and Clément Miège
Lake and Rio Behar views from the helicopter. (Photo courtesy Clément Miège.)

Lake and Rio Behar views from the helicopter. Photo by Clément Miège.

This summer, we have the chance to be part of a team of researchers studying the efficiency of the drainage system over the ablation zone of the Greenland ice sheet. This NASA Cryosphere program funded project, titled “Drainage Efficiency of the Greenland Ice Sheet” is studying the production, transport and export of Greenland Ice Sheet meltwater and its importance for global sea level rise. Each summer, a complex yet poorly studied system of thermally eroded meltwater streams forms across the surface of the Greenland Ice Sheet and transports meltwater into the ice sheet via moulins. Meltwater then exits the Greenland Ice Sheet and makes its way to the global ocean via land-based proglacial rivers and buoyant sediment rich plumes. This project intensively maps, monitors and measures both supraglacial and proglacial rivers to improve estimates of Greenland Ice Sheet surface mass balance and its impacts on global sea level rise.

To achieve these objectives this project will:

  • Monitor meltwater outflow through proglacial rivers
  • Study cryo-hydrologic processes on the edge of the Greenland Ice Sheet
  • Intensively monitor a supraglacial hydrologic catchment in the mid ablation zone of the western Greenland Ice Sheet
  • Monitor surface ablation
  • Understand the proprieties of the weathering crust and its links to supraglacial rivers

To do this work, we will be located in the ablation zone of Greenland ice sheet, at about 80 km from Kangerlussuaq (the closest town) and 1200 m elevation. Our study site is located right next to a lake and a river called the Rio Behar. As you can see from the photo above, this part of the ice sheet is covered by lakes and rivers that are transporting meltwater away from the ice sheet throughout this connected system.

To study this area, we have researchers from different universities coming in with different background, therefore bringing various expertise and skills to ensure success of this expeditions.  The two main institutions responsible for this work are UCLA (Project PI Larry Smith, and his students Lincoln Pitcher, Matt Cooper, Sarah Cooley) and Rutgers University (Project Co-I Asa Rennermalm, and her students Rohi Muthyala and Sasha Leidman. They were also able to invite a few additional researchers to complete the field team. Brandon Overstreet comes from the University of Wyoming and will be in charge of the river work to measure river flow and discharge. Johnny Ryan is at Aberystwyth University in the UK and will be flying over the entire catchment area with a fixed-wing drone. Charlie Kershner is based at George Mason University and will lead terrestrial lidar scanner (TLS) measurements to get high-resolution surface topography and deduce melting rates. Finally, Clem Miege is at the University of Utah and will be leading ground-penetrating radar measurements to look at the weathering crust and any englacial features.

Team posing in front of the helicopter that will take us to our ice camp. From left to right we have: Johnny, Charlie, Rohi, Asa, Matt, Clem, Sarah, Larry, Sacha, Brandon and Lincoln.

Team posing in front of the helicopter that will take us to our ice camp. From left to right we have: Johnny, Charlie, Rohi, Asa, Matt, Clem, Sarah, Larry, Sacha, Brandon, and Lincoln.

To complement, the ice camp work which will take place between July 4 and July 14, a few team members will also monitor proglacial rivers and streams near the glacier edge. Matt, Sacha, Sarah and Rohi are leading this effort and invited Charlie and Clem to come over and test their equipment on the ice edge. This test day was great, as you can see from the few photos below.

Charlie is testing his Lidar system at the edge of the ice sheet. Credit: Lincoln Pitcher.

Charlie is testing his Lidar system at the edge of the ice sheet. Photo by Lincoln Pitcher.

Charlie’s Lidar in action at the river bend. Credit: Charlie Kershner.

Charlie’s Lidar in action at the river bend. Photo by Charlie Kershner.

Charlie and Clem are carrying the ground-penetrating radar over the glacier, the surface roughness made it difficult for the radar to operate. Credit: Lincoln Pitcher.

Charlie and Clem are carrying the ground-penetrating radar over the glacier, the surface roughness made it difficult for the radar to operate. Photo by Lincoln Pitcher.

That is about it for now as we are finishing sorting through our equipment before getting to our ice camp.

In the coming posts, we will send updates on how the work is going on the ice sheet and also describe the different components of this multi-disciplinary work in more details. I hope you will enjoy reading about this exciting research project.

Thanks and best wishes,

Clem and Lincoln

Arctic-Boreal Vulnerability Experiment (ABoVE): ABoVE and beyond the call of duty: the value of a great field team

June 24th, 2016 by Brendan Rogers

As our 2016 field campaign comes to an end, I find myself proud of all the great data we collected. Our primary objective was to sample enough sites of different ages, land use, and species composition to be able to say something meaningful about changing fire regimes and the interactions between wildfire and timber harvest. I’m confident we accomplished this. In a way though, the work has just begun. Now we must conduct laboratory tests on many coolers worth of soil, count hundreds of tree rings, pour over the data, interpret the results, and write it up for publication. But none of this would be possible without collecting the amount of high-quality field data we did.

Catherine Dieleman, preparing to dig a soil core.

Catherine Dieleman, preparing to dig a soil core.

In fact, none of this would be possible without something much more fundamental: an amazing team. We came from Massachusetts, California, Ontario, and Belgium. We are at varying stages of our careers but were all excited to be there, with our hands in the dirt collecting data. We woke up early and got home late. Our bodies were sore. There were any number of cuts, scrapes, and bruises. We were always dirty, especially the days sampling burned forests when everything you touch is covered in soot and char. Bogs and rain made for wet boots and wet socks. Oh and the bugs. When the black flies and mosquitos began to relent they were replaced by deer and horse flies.

Each team member had their personal battles, their moments and days of drudgery. But they all found a way to power through. The only complaining I heard was in jest, to lighten the mood and make for a few laughs. And we had a lot of laughs. We thoroughly enjoyed each other’s company. Given the situation, having to work hard and spend every minute of the day together, I think that is a rare and wonderful thing.

Liz Wiggins and Jocelyne LaFlamme, packed up and ready to walk to the next field site.

Liz Wiggins and Jocelyne LaFlamme, packed up and ready to walk to the next field site.

Someday soon our plots will be boiled down to points on a map, or included in a model. Some will read and cite our papers, or use a figure in a presentation. Hopefully we will have made a valuable contribution to science, and to NASA’s ABoVE campaign. But only we know what each one of those plots felt like. The young pine forests thick with prickly brush. The old-growth pine and spruce that felt so majestic in comparison. The failed plots that never were. And that one where the ‘forest chicken’ attacked us. Or was it a mini-ostrich? Hard to say. (It was a grouse.)

Someone wise once told me you can teach science and you can teach methods. But you can’t teach attitude. A positive attitude will keep you afloat through the tough times and make you appreciate the good. A bad attitude will make everything difficult. Attitude is the primary quality I look for in team members, and boy did I luck out with this crew.

Thank you to my team for making this field campaign such a great success. Thank you Jill Johnstone and her crew for all their good will and hard work. Thank you Saskatchewan for being such a lovely host. And thank you NASA for giving us this opportunity.

Until next time. Rogers field team – over and out.

Brendan Rogers is a project lead with the ABoVE campaign, and an assistant scientist at the Woods Hole Research Center in Massachusetts.

Arctic-Boreal Vulnerability Experiment (ABoVE): ABoVE: Burned boreal forests — Come along to measure carbon

June 20th, 2016 by Elizabeth Wiggins

As part of our field work to measure carbon emissions in burned areas, we often have to hike through an obstacle course of fallen trees to reach our research sites. I took some video with a GoPro to give a sense of what this is like, as well as how we extract soil to take measurements and how we find the perfect sites.

 

Elizabeth Wiggins is a PhD student in the department of Earth System Science at the University of California, Irvine.

Arctic-Boreal Vulnerability Experiment (ABoVE): ABoVE: Burned boreal forest — Site-seeking struggles

June 14th, 2016 by Jocelyne Laflamme

In the field, collecting the data is a big job – but our work starts long before we start taking measurements, with the task of finding desired sites within the landscape.

Jocelyne coring a tree to determine the age of the forest (Credit: Sander Veraverbeke)

Jocelyne coring a tree to determine the age of the forest (Credit: Sander Veraverbeke)

As our time in Saskatchewan progresses, choosing and finding the right places to collect data becomes progressively more difficult. We are looking for a wide range of forest ages and species composition. This becomes more and more challenging as the time passes, since we now need to find sites with the particular characteristics that we are missing. To find these places, we look at maps that show when and where fires have occurred, and combine this information with maps from logging companies that show location and dates of timber projects.

Every day, we head out to several sites that we identified the night before. We usually drive an hour or so on gravel roads, and hike several hundred meters into the forest. We check for the right species composition at the site, and use a tool called a tree borer to extract a thin cylinder from a nearby tree trunk. From this tree core, we can count the number of rings and determine the approximate age of the forest. If the forest age and species composition meet our expectations, we finally begin our data collection. If not, we return to the car and attempt another location.

It can be challenging when we don’t find what we expected, which can result from inaccuracies in the map layers we use. At times this can be frustrating, but thanks to our team’s stamina, we always eventually manage to find what we need. With only a couple days left in the field, all the gaps in our data will soon be filled.

Jocelyne Laflamme is an undergraduate student in Wildlife Biology and Conservation at the University of Guelph in Canada.

Arctic-Boreal Vulnerability Experiment (ABoVE): ABoVE: Fires in recently logged forests

June 10th, 2016 by Kylen Solvik

Since our last post, our team has moved an hour south to the small village of Weyakwin, where the Philion fire burned last year. There is a lot of logging Weyakwin, and we are very interested in the interactions between fires and logging. We are comparing burned forests that grew back after people cut trees, to those that grew back after an earlier forest fire.

 Sampling a young harvested site that burned last year. It was harvested only a year or two before it burned. (Credit: Solvik)


Sampling a young harvested site that burned last year. It was harvested only a year or two before it burned. (Credit: Solvik)

We believe there could be differences between the two in burn severity and the amount of carbon released by the fire. When a plot is harvested for lumber, the logs are removed but the soil remains. This is the opposite of burned areas, where fire burns into the soils but a lot of the trees remain standing, albeit charred. To study these differences, we are searching for areas of burn and harvest origin that are about the same age. We have seen some very young burned sites, many were less than 10 years old when they burned. This is surprising since forests in boreal regions typically burn when they are 50 to 100 years old. We were shocked to find a burned plot that had been harvested only a year or two earlier. Even without any significant trees or shrubs to carry the flames, the soil was able to sustain the fire.

At the sample sites, my job is to help characterize and quantify the aboveground biomass. This includes trees, shrubs, and dead trees that have fallen over, called “coarse woody debris.” I work with Brendan Rogers, our team leader, to measure every tree within a 2-by-30 meter sampling area. We identify the tree species, rate the amount of the canopy consumption, and measure the diameter. We will use these numbers to estimate how much carbon was released when that tree burned. Most of these tasks are fairly straightforward — although it can sometimes be tricky to differentiate between similar tree species after they have burned. We can measure individual trees pretty quickly, but it can still take one or even two hours to work through an entire site. At one site, we counted over 350 trees, measuring the diameter and estimating the canopy consumption for each and every one!

Our team and Rita. From left to right: Kylen Solvik, Liz Wiggins, Rita, Brendan Rogers, Sander Veraverbeke, and Jocelyne Laflamme. Missing: Catherine Dieleman, who had to fly home early for a friend’s wedding. (Credit: Solvik)

Our team and Rita. From left to right: Kylen Solvik, Liz Wiggins, Rita, Brendan Rogers, Sander Veraverbeke, and Jocelyne Laflamme. Missing: Catherine Dieleman, who had to fly home early for a friend’s wedding. (Credit: Solvik)

In Weyakwin, we are staying at a small bed & breakfast. Our host, a wonderful lady named Rita, takes great care of us. She cooks us breakfast and dinner, and she even packs us brown bag lunches for us to grab on our way out. After going out for dinner every night at our previous lodging in La Ronge, it has been a great change of pace eating home-cooked meals. We will be staying with Rita for the next week, and then we will be returning to Saskatoon to fly back to our respective homes. One of our team members, Catherine Dieleman, left early for her friend’s wedding. We will miss her and her soil expertise dearly.

But there are a lot more sites to sample before we are done!

 

Kylen Solvik is a research assistant at Woods Hole Research Center in Falmouth, Massachusetts.

Notes from the Field