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Archive for the ‘Alden Adolph’ Category

You never know what you might come across in the tundra of Kangerlussuaq – particularly if you know where to look! Keeping with the IGERT tradition, Cohort 4 spent one of our evenings in the field on a treasure hunt set out by the cohorts that came before us.

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Setting out on our adventure – shovel at the ready!

With a combination of challenges that tested our orienteering, our knowledge of Grateful Dead and Greenland, and our digging endurance, we wandered around Seahorse Lake on a quest for treasure and glory.

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Ruth makes a crucial discovery – to the rock turtle!

It was fun to follow in the footsteps of the cohorts that came before us as we paced our way from clue to clue.

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Creating our plan of attack to get to the next clue.

As we came to the final clue and had found our buried treasure site, we furiously dug through the organic layer and the down into the soil. When we hit the frozen soil with no signs of treasure, we thought something may have gone awry, but we persevered. After all, Cohort 3 warned us, “We hope you are buff, ‘cause this might be tough,” and how could we turn down such a challenge? After over an hour of chipping away at the icy ground, the treasure was revealed!

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Zak chips away at the frozen soil as we eagerly await the big reveal!

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Celebrating the fruits of our labor as we all stand in the hole at the site of our buried treasure!

Many, many thanks to Cohorts 1, 2 and 3 for preparing this fun adventure for us! Y’all are awesome!

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Feeling the IGERT love!

Photos by Jess Trout-Haney.

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What’s cooler: snow pits or soil pits? Among the IGERT group, that could be a bit of a loaded question. I may be just a tad biased, so I will diplomatically bow out of answering that question directly, and instead present the facts that I’ve gathered about snow and soil and what we can learn from them.

Creating the pit

Digging is digging is digging. If you want a hole in the ground, you’ve found the right group! We love it so much that we have even created a dance move to celebrate digging.

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Whether in the tundra or on the ice, the IGERT crew can conquer any digging challenge.

Layers and Horizons

One feature shared between both soils and snow is their tendency to form stratigraphic layers. In snow, these layers can be seasonal or from particular storm events. As more snow accumulates every year, and the layers remain frozen even through the summer, the layers continuously build on top of one another. In soils, the layers are referred to as “horizons.”   The uppermost horizon is known as the O-horizon, which is an organic rich layer, followed by the A, B and C horizons. Proceeding downwards, the horizons become decreasingly organic and increasingly mineral rich until you reach the parent material beneath the soil.

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Stratigraphy in the snow and firn at Summit (left) and in the Sandflugtdalen of Kangerlussuaq (right).

Dating

In both soil and snow pits, isotopes can be used to estimate the age of the horizon. In high snow accumulation areas, the snow layers show seasonal trends in oxygen isotopes. Counting back from the surface allows researchers to determine the age of layers. In soils, any remaining organic material in the soils can be dated by analyzing the isotopes of carbon. Histories can be unraveled in both snow and soil by tying the age of the horizons to other properties. In soils, this could be an investigation of what types of plants were growing at a time in the past. In snow, this could be a study of how carbon dioxide in the atmosphere has changed over time. In either case, the story needs a timeline and isotopes provide the tick marks for us.

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Though I was skeptical at first, Ross’s module on soil horizons won me over!

Density

In seems that across many disciplines, density measurements are used as a simple way to characterize a material. We found ourselves measuring density along snow pit walls at Summit and in deflation zone scarps in Kangerlussuaq.  Not surprisingly, the least dense loess sample in our soil studies was far denser than even the ice samples that we measured at Summit.

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Ruth and Kristin measure snow density at Summit (left), and Zak measures loess density in a deflation zone scarp (right).

Little known perks

We’ve also managed to explore some of the lesser known perks of soil and snow pits. We have found that covered snow pits create a perfect venue for puppet shows. And though it’s a bit of an acquired taste, Zak has found sandy soils to be quite a delicacy!

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Zak tests the grit of the soil against his teeth.

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Deflation patches are everywhere! Well, more accurately, they are often on south facing slopes and relatively close to the ice sheet. Ruth, our resident deflation patch expert, has been taking Cohort 4 around to lots of deflation patches so that we can measure how much vegetation is present in and around the patches. Deflation patches are easy to identify- they are areas of exposed rock and loess (sediment deposited by wind) in an otherwise vegetated ground cover, with a ‘scarp’ on the uphill edge of the patch.

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deflation patches and their furry friends

Deflation patches expand when wind digs away at the loess and the surface vegetation no longer has anything under it; so, the presence of a scarp, or wind-eroded cliff, can often be the tell-tale sign of a deflation patch.deflationpatch2These patches can vary in size from a few feet to hundreds of feet across. Judging from all of the satellite and airborne imagery that we have attained, the deflation patches have not expanded noticeably in the last 70 years!

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Ruth explaining deflation patches- my “Ah ha” moment!

A lot of our work on deflation patches has been to go out to many randomly chosen locations within Ruth’s study areas and simply record what we see (Ruth will later compare these observations to her satellite imagery). So out we all go with Ruth, hiking up and down the rolling hills of Kangerlussuaq with a 0.5 m by 0.5 m PVC quadrant in hand. We lay down the quadrant and estimate a percentage of vegetation cover for that location. Next, Ruth types in a new survey location and the GPS leads us off into the hills again. We have over 100 randomly chosen locations to visit during our stay at Sea Horse Lake.

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Ruth and Zak estimating vegetation cover

Since the airborne imagery of this area is fairly recent, and deflation patches expand slowly, we need some other way to determine the age of these patches. Enter lichenometry! Lichens are capable of existing in some of the harshest environments on Earth- out here in Greenland they come in many varieties and colors, but all seem to enjoy growing on rocks. A few characteristics of lichen make them useful for dating: 1. They need the sun to grow and 2. They expand at a predictable rate. By measuring the width of lichen on rocks within the deflation patches, we can determine when the loess that covered them was removed. Ruth, to date, has already measured over 3,000 lichens!

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A triumphant Ruth after recording her last ‘percent vegetation cover’ measurement!

Being out here in Kangerlussuaq with Ruth, I was finally able to see the deflation patches and lichen she’s been writing proposals and talking about for the last year- it’s incredible to see everything finally coming together! Cohort 4 has had lots of fun going on deflation patch hikes and estimating vegetation cover during our time at Sea Horse Lake- be sure to check back in and see all the other science we’re doing up here!

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How Many IGERTeers Does It Take To Haul 1,000 Pounds of Water?

When I applied to graduate school, I had my heart set on studying how pesticides bio-accumulate in squid after being carried from one side of Costa Rica to the other via the seasonal trade winds. After many false starts and dead-ends (and almost five years later) the focus of my dissertation is on the effects of altered flowering phenology on plant-pollinator interactions and plant reproduction. To say I changed course would be a major understatement. Would my squid idea have worked out?  Probably not.  Had I done any research into the topic?  Pfft, of course not! It just sounded like a fun idea. So how did I go from a crazy, squid-based research idea to a more interesting, practical, and basic-science oriented question?  Through a lot of trial-and-error and helpful advice from my committee and advisor.  Thanks, guys! But chasing kooky, quixotic ideas and getting pulled back to earth is all part of the graduate school experience. And it’s a healthy experience, I think.  I have to admit it is satisfying to look back and see the progress that I have made, and it is equally satisfying to see the progress that the other members of my cohort have made.

Julia Bradley-Cook teaches us about carbon in soils and the atmosphere near her field sites in Kangerlussuaq, Greenland

Julia Bradley-Cook teaches us about carbon in soils and the atmosphere near her field sites in Kangerlussuaq, Greenland

Julia Bradley-Cook, a friend and fellow IGERTeer, has just wrapped up a field season here in Greenland.  We were lucky enough to spend some time with her in the field before she finished what will likely be the last field season of her dissertation. It was an amazing experience for me because Julia and I are in the same cohort in the Ecology and Evolutionary Biology (EEB) program at Dartmouth, and I have seen her research develop over the past four years through her talks and presentations at Dartmouth. But this was my first time seeing Julia’s science first hand, in the field. And while my research dramatically changed directions (several times) during my first couple years as a graduate student, Julia is literally doing the polar opposite of what she had initially set out to study.

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Julia laughs as Ross breathes into the infrared gas analyzer, increasing the CO2 levels.

I clearly remember Julia’s first talk at Dartmouth, in which she proposed studying soil carbon flux in the dry valleys of Antarctica. She went to Antarctica, tried out her ideas, and like most graduate students failed to generate data that would turn into a dissertation.  Sad, but true.  Then she decided to follow a similar line of research in an environment that was better matched to her research question: in the arctic rather than the Antarctic. Julia’s current work focuses on how arctic soil respiration will respond to an increase in precipitation.  She explained to us that the atmosphere contains about 750 gigatons carbon. Soils, on the other hand, have about 3,200 gigatons globally.  That means that soils hold over four times as much carbon as the atmosphere! Mind blowing.  What’s more, about half of all that carbon is in arctic soils, if you include boreal forests.  Climate change models predict that precipitation in Greenland will increase by 15% by 2050 and by 50% by 2100. How are the arctic soils going to respond to this increase in precipitation?  That is one of the main focuses of Julia’s dissertation, and to investigate the question she is adding water to 18 plots, each paired with a control plot, and then measuring soil respiration using an infrared gas analyzer.

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Alden takes some soil respiration data!

So far she has been adding 6 liters of water to each plot, which reflects a realistic increase in precipitation over the next 90(ish) years.  Her results have been quite interesting thus far, although some could argue that the results are a bit ambiguous.  So she decided that she needed to take a sledgehammer approach: add an enormous amount of water, and see how soil respiration is affected. That way there would be no ambiguity as to the response to water itself, and then she could use those data to help interpret her more realistic water additions. For the sledgehammer approach, she decided to add 24 liters of water to each plot over the course of a very short period of time and then take soil respiration measurements every ~12 hours over the following few days. 24 liters of water * 18 plots = 432 liters of water total.  Remember that 1 ml of water has a mass of 1 gram, so 432 liters of water has a mass of 432 kilograms.  What’s more, the water needed to be hiked up to her sites from a lake.  Woof.  That’s a lot of work. And it would have been nearly impossible for Julia and her hard working assistant Leehi to have done it by themselves. Luckily, IGERT cohort 4 (later named “Totally Awesome Cohort” by Ross) was there to help!

I practice the spraying technique.  If I do it right, 12 pumps = 1 liter of water!

I practice the spraying technique. If I do it right, 12 pumps = 1 liter of water! photo by Leehi Yona

Once we hiked up to the sites carrying a backpack filled with five gallons of water, we needed to get the water onto the plots.  We used two techniques for this, one slightly higher tech than the other.  The first was to dump the water, one liter at a time, through a colander.  The colander helped to spread the water out as it fell, much like a sprinkler.  The second approach was to use a backpack with a pump-sprayer attached.  I have used similar backpacks before, but this was a new design for me.  Apparently the one we were using is made for firefighters.  I have to say, I feel bad for those firefighters.  The backpack would leak about a third of its water down the back of the wearer, and using the pump spraying was surprisingly draining! But technical difficulties aside, we managed to haul all the water up and apply the treatments to her plots. The next few days were an insane push for Julia to take all of the necessary measurements and prepare for her departure, but she managed to pull it off. Congratulations, Julia, on wrapping up another field season, we can’t wait to see how the data turn out!

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Bombus!”  Kristin sounds the alarm, pointing toward the large buzzing bumblebee attracted to her white baseball cap.  Immediately, Christine, armed at all times with her insect net, springs into action.  I’ve never seen someone run so quickly across the tundra – Christine running after a Bombus is truly an amazing sight.

Christine poses with her ever-present net.

Christine poses with her ever-present net.

“Wham!” Christine’s net hits the ground.  Success again!  Trapped inside her net is a surprisingly large (at least the size of two Hershey kisses) bumblebee, buzzing in anger and confusion.  With no hesitation, Christine expertly slips a vial into the net, taps the bee into the vial, and there – another sample caught!

Ivalu holds one of captured bees while Kristin skeptically looks on.

Ivalu holds one of captured bees while Kristin skeptically looks on.

In Greenland, there are two bumblebee species: Bombus polaris and Bombus hyperboreusB. hyperboreus is a parasitic bee – that is, the queens will take over a B. polaris nest and trick the worker bees, who never realize they aren’t working for their own queen.  Not many people have studied bumblebees in the Arctic, so with each Bombus capture, Christine added valuable information to what we know.  A good reason to celebrate each new sample!

A bumblebee visits Niviarsiaq, the national flower of Greenland.

A bumblebee visits Niviarsiaq, the national flower of Greenland.

From our pollination experts Christine and Zak, we also learned that arctic plants are often pollen limited.  If the flowers are given additional pollen, they are able to produce more seeds.  In order to get more pollen, plants compete for pollinators, putting on showy displays and enticing insects with yummy nectar.  To test just how pollen limited arctic plants are, Christine had us set up a simple experiment using Niviarsiaq (the national flower of Greenland).  On some plants, we tied mesh bags around flowers to exclude pollinators.

Mesh bag placed around Niviarsiaq flowers to exclude pollinators.

Mesh bag placed around Niviarsiaq flowers to exclude pollinators.

On other plants, we added pollen by hand, mimicking the role of a bumblebee.   A third set of plants we identified as controls.  Later this summer, Christine will collect the seedpods from all of the plants and compare how many seeds each plant was able to produce.  If the hypothesis is correct, and the plants are pollen limited, the hand-pollinated plants should be the most successful!

Last year, after living in the tundra for six full weeks, I hadn’t given pollination a thought.  I vaguely remembered seeing what might have been a bumblebee.  This year, however, my perspective has completely changed.  Whenever I hear the frequent buzz of Bombus, my head immediately turns and I think, “Go, Christine, go get it!”  Many thanks, Christine and Zak, for teaching us the art of Bombus-ing!

The Bombus itch spreads -- Alden catches her first bumblebee!

The Bombus itch spreads — Alden catches her first bumblebee!

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While up at Summit camp, we were fortunate to overlap with students from the Joint Science Education Project (JSEP). The program provides high school students from Denmark, Greenland and the United States with the opportunity to travel to Summit Station and learn about the scientific research that occurs there. The ladies of Cohort 4 were eager to share our polar knowledge with the JSEP students, so we set up four different activities that revolved around snow and ice.

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Summit flies flags from all of the participating countries in the Joint Science Education Project.

The first activity took the students out around camp to investigate snow albedo. We searched for snow that somehow looked different. For example, these differences could be due to compaction from heavy equipment, exhaust from LC-130 planes, or frost flower growth on the surface. We made measurements of albedo and used hand lenses to take a closer look at the snow grains and see how they differed from place to place.

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Looking at snow grains through a hand lens.

One afternoon took us down to the beautiful backlit snow pit, where we discussed snow layering from different storm events and different seasons. We analyzed the snow stratigraphy, made density measurements and talked about implications for ice core studies, like the research done on GISP2 right at Summit!

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Measuring density in the backlit snow pit.

Kristin led a hands-on exercise to teach the JSEP participants about glacial flow. The students made their own flubber from glue, water and borax, and they ran experiments to determine how their flubber “glaciers” would flow under various “bedrock” conditions. A wee bit messy, but worth the clean up!

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Kristin explains the physics of glacial flow using flubber!

Our last afternoon at Summit fell on a beautiful, warm, sunny-sky day. The JSEP students broke into teams and set out on a scavenger hunt! Using GPS coordinates or clues about things around camp, the students were led place to place until they reached a final clue that could only be solved with input from all three groups. At last, they found the long sought-after buried treasure of Summit Camp!

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The buried treasure of Summit Camp is found!

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Coveted penguin stickers in the scavenger hunt prize!

When we weren’t sharing our love of science, the IGERT and JSEP teams enjoyed other activities around camp, such as singing songs together in the Big House or playing board games in the Recport. It was a fantastic opportunity for the IGERT students to share our science, to learn about science education in other countries, and to have a great time while doing it!

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JSEP and IGERT groups after a successful scavenger hunt!

Learn more about the JSEP program at their website: http://www.polartrec.com/expeditions/joint-science-education-project-2013

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The Greenland Ice Sheet holds many stories of past climate. Summit Camp, in fact, was established for scientists to drill two miles down into the ice and pull out an ice core that tells a story of warming and cooling events from the past 100,000 years.

Ten years and 1 week after the completion of this GISP2 drilling operation, the IGERT C4 gals made our way up to Summit and uncovered a new story held in recent ice.

Alden, Kristin, Christine, and Ruth at the site of GISP2

Alden, Kristin, Christine, and Ruth at the site of GISP2

In July of last year, as you may recall, 97% of the Greenland icesheet experienced surface melting.

While much of this melt refroze on the surface,  some melted snow flowed below the surface to form frozen fingers poking down through layers of previously fallen snow. The frozen fingers, which we call vertical flow channels, are like icicles that are suspended in snow rather than air.

A trip to a backlit snowpit introduced us to the melt layer and one vertical flow channel. These features were buried 75 cm below the surface by a year’s worth of snow.

Unlike surrounding layers, the melt layer and the vertical flow channels were icy, clear, and hard; easily distinguishable with the naked eye or the touch of a finger running down the snow pit wall. It is important for scientists to study these icy features to better understand the physics of water flow through snow and to understand how their  properties may affect the information that satellites and radar collect about the ice sheet.

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Alden showing us the snow pit. The green arrow points to the melt layer, the white arrow points to a vertical flow channel (i.e., finger).

Our mission was to dig under the frozen melt layer and excavate any ice fingers we could find.  We were like archeologists, hoping to discover arctic artifacts.

We first uncovered the snow pit that Alden had dug earlier in the season.

Removing the snow from plywood that covers the snow pit.

Removing the snow from plywood that covers the snow pit.

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Revealing the snow pit.

Then Alden and Kristin graphed the stratigraphy of the snow pit layers to document the depths of the melt layer, winter and summer snow, and wind crusts.

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Kristin’s lovely stratigraphy diagram

With our hands protected by waterproof mittens and zipbloc bags, we swept away the snow under the melt layer, feeling for any icy vertical flow channels. Kristin and I found several frozen fingers right away and started excavating by delicately brushing out the snow around them until we reached their icy bottom tips.  It took me 2 hours to excavate a beautiful flow channel that was one-half meter long.  We measured the fingers, recorded their position, and made notes about their form.

Carefully excavating a finger, which I nicknamed ‘Precious’.

Alden and Ruth worked on a side of a snow pit that seemed to have a different flow pattern. They diligently dug back through 1 meter of snow but didn’t uncover any frozen fingers.

While Kristin and I chip away at our excavations, Ruth and Alden continue to dig back, looking for vertical flow columns...the snow pit is getting larger!

While Kristin and I chip away at our excavations, Ruth and Alden continue to dig back, looking for vertical flow channels…the snow pit is getting larger!

As we reached the corner of our site, Mary found a behemoth vertical flow channel. We named him Hector II. Tired and cold, Ruth and Alden quickly sawed, shoveled, and pried Hector II out of the snow so that we could return back to camp.

After dinner, Mary, Ruth, and I excavated Hector II ex-situ and loaded him and our other frozen fingers into an insulated ice core box. We covered the fingers with cardboard, snow, and icepacks to make sure that they would stay frozen on their trip back to Dartmouth College.

Ruth carrying Hector II - all wrapped up - to the ice core box.

Ruth carrying Hector II – all wrapped up – to the ice core box.

We made one last trip to the snow pit…this time on a snow mobile. I was particularly excited about this arrangement. We blazed across the ice sheet at a whopping 5 miles per hour, filled in our digging site, and recovered our tools.  Although the work was difficult, we were grateful to be at Summit a year after the surface melt, when the ice fingers were still within reach of a shovel and the hands of four motivated IGERTs.

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Celebrating a job well done

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