Archive for the ‘Thomas Overly’ Category

In the summer of 2012, I had the fortune of meeting up with Dr. Carl Benson (see “Meeting people in Alaska …“), where we chatted about his previous traverses on the Greenland Ice Sheet and some of his current scientific endeavors. I was fascinated with his stories as my 2011 traverse with Thomas Overly and company was still fresh in my mind. As luck would have it, the Dartmouth IGERT community continues to interact with Benson.

Carl Benson and his report
It all started with a picture … Photo courtesy R. Benson.

In December 2012, while attending the AGU science conference with Chris Polashenski, I had the fortune of meeting Betsy Turner-Bogren from ARCUS (Arctic Research Consortium of the US), and we briefly chatted about an interview concept that reminded me of my August conversation with Benson. ARCUS has a newsletter it produces, Witness the Arctic (WTA), that provides “information on current arctic research efforts and findings, significant research initiatives, national policy affecting arctic research, international activities, and profiles of institutions with major arctic research efforts.” “Arctic Generations,” a series within WTA, is where an early career scientist gets to interview a scientist with “a long, distinguished career.” I could not pass up this opportunity to bridge the ground-breaking science, research techniques, and logistics accomplished by Benson and his traverses with the 2011 Greenland Inland Traverse. You can find the interview here. While we touched on some science, I was also intent on bringing out some of his personal memories of the traverse – my favorite anecdote is about the air logistics and, in particular, the French “free drops” along the 1955 traverse.

I’m not the only IGERT’eer chatting Benson up. Indeed, Chris is collaborating with Benson for his 2013 traverse of the Greenland Ice Sheet experiment (known as “SAGE”: Sunlight Absorption on the Greenland ice sheet Experiment). Recently, Chris shared his experiences and some of his initial findings at an IGERT-sponsered talk here at Dartmouth. A blog of his 2013 traverse can be found here.

For me, this illustrates one of the neat aspects of snow and ice core science – its a very young science. What I mean by this is that many of the techniques developed and initial studies happened within the last 50-60 years, and many of those pioneering researchers are still pushing the envelope of knowledge today. The opportunity for a young scientist, like myself, to talk with giants in their field is unique.

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I admit, I can be a little nerdy at times. And, in light of my current alma mater, let us conjure Dr. Suess’s imagining of the word [If I Ran the Zoo].

This being said, my Alaska trip became a cornucopia of chance encounters and coincidental run-ins, from people who live in Boston to people I’ve worked with on Polar ice sheets! While I would like to write about all of them, I’ve whittled the “run-in” list to three: Denali National Park, Julia Gourley, and Dr. Carl Benson.

Perhaps its fitting to mention Denali National Park first. It wasn’t until after I was asked to present a poster at the following week’s Week of the Arctic conference that I even thought to visit this majestic park. First established in February 1917 (as Mt. McKinley National Park), Denali NP now sits at 7,329.2 sq. miles, with an additional 2,089.9 sq. miles “buffer” in its preserve. For comparison, New Hampshire (9,279sq. miles) is slightly smaller than the whole of the park and preserve. Denali, or “The High One”, is the Athabaskan name for the mountain that serves as “the roof of the continent”*. My visit was short (day trip aboard a shuttle bus to Eielson Visitor Center), but it was punctuated by numerous animal sightings and my good friend (and shuttle driver), Dawn, that I met while working in Antarctica. I hope to re-visit this marvelous area sometime soon!

Grizz with springer cubs
Mother grizzly with her two springer cubs.

Coyote on the road
Coyote walking the road to Eielson Visitor Center.

The Wednesday poster presentation was actually part of a general invitation to participate in the Institute of the North‘s Week of the Arctic. Although I did not have time to spend all week in Anchorage, I was able to participate in Tuesday’s session (Arctic Council Strategic Planning and Luncheon) where Senior Arctic Official Julia Gourley (State Department) was a speaker and guest. Her role is to help lead US foreign policy development in the Arctic, and it was fascinating to hear her explain the structure of the Arctic Council (high-level diplomatic forum for international cooperation in the Arctic with 8 member states and 6 permanent participants), illuminate some of the key issues currently facing the Arctic, and engage with the conference participants. I only got a chance to chat with her for about 10 minutes, but I invited her to come to Dartmouth and speak with our IGERT folks … let’s hope her schedule allows!

Perhaps the biggest meeting of the trip, in my estimation, was my evening spent with Dr. Carl Benson (and his wife, Ruth). For those keeping score, Carl planned and led a series of traverses (1952-55) that led to his oft-read 1962 CRREL report that, among other things, defined the concept of glacier facies. Indeed, his traverses were the basis for the 2011 Greenland Inland Traverse that Thomas and I undertook last spring. What fun that was! The evening was a mix of tales of derring-do and nostalgia, from train platforms in Evanston, IL, to the great, flat white of the Greenland Ice Sheet. Perhaps most fortunately, Carl delved into some of the glaciological questions that he’s still thinking about … a treasure trove indeed! With luck, I’ll be able to incorporate some of his curiosity into my still-developing thesis! Thanks for a wonderful night, Carl and Ruth!

And thanks, IGERT, for a wonderfully opportunistic Alaskan trip!

Carl Benson and his report
A picture with a legend! Photo courtesy R. Benson.

* Information from http://www.nps.gov/akso/parkwise/students/parkfacts/DENA_FastFacts.htm

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[as seen in Dartmouth’s The Graduate Forum (newsletter)]

As graduate students, we all share this singular pursuit, this unabashed chase of scholastic glory. We all enjoy the burden of late nights glazed with copious amounts of caffeine and buoyed by an endless sea of scientific papers. We all enjoy the bucolic wonders of Hanover and the Upper Valley, the unrelenting, yet rewarding, joys of being a graduate student at Dartmouth College. If you’re reading this, I imagine you are, like me, toiling away at some novel and intractable question while balancing the rest of your life. Not easy, but we’re all getting by. So what happens when, in the midst of this sometimes-stultifying stupor, you find yourself on the front-end of a 40-day traverse of the Greenland Ice Sheet?

Buy sunscreen!

The 3 amigos ... Thomas, Galen & Giff
[Getting ready for a day of snowmobiling! From left: Thomas Overly (IGERT), CH2MHill-supplied mountaineer and all-around awesome guy Galen Dossin, and Gifford Wong (IGERT)]

That is what I did when I found myself days away from joining the 2011 Greenland Inland Traverse (GrIT). GrIT, conceived primarily as an overland supply-run for the year-round science station at Summit Camp located on top of the ice sheet, recently became open to the idea of supporting science. The first leg of the journey is a flight from Baltimore, Maryland, to Thule Air Base on the northwest coast of Greenland. Thule Air Base is the US Armed Forces’ northernmost installation, located 750 miles north of the Arctic Circle, and serves as the home base and garage for GrIT, a joint operation involving the National Science Foundation (NSF), the US Army Cold Regions Research and Engineering Laboratory (CRREL) and CH2M Hill Polar Services.

Professor Robert Hawley, in the Department of Earth Sciences, originally proposed the idea of pairing science with this traverse. He passed this tremendous field opportunity to two of his current graduate students – Thomas Overly and Gifford Wong (yours truly). Some of the fantastic reasons, science-wise, why this traverse was so tremendous were it provided a comfortable (relatively) platform from which to perform ground truthing studies, it was an opportunity to revisit science sites along a route that was first studied in the 1950s by Carl Benson, a CRREL-based researcher, and it lead to a wealth of data for his lab group to sift through for the next couple years.

Sunset ...
[Sun setting behind one of our Case Quad-tracks.]

But that’s not all. Nearly everyone enjoys fantastic, and sometimes far-flung, field adventures. For me, the thing that made this past field season so special was the traverse itself. It is the journey that is interesting. I’ve been fortunate to participate in polar science before (McMurdo Station [see pg.3], West Antarctica, Summit Station, and Byrd Surface Camp [see “Views of a Deep Field Virgin”, pg.11]), but I’ve never had to drive there. I’ve never had to submit myself to 1400 miles worth of ice sheet whimsy. I’ve never had so much of my livelihood rely on what continually seemed like never-long-enough days. And, I’ve never had the fortune to be surrounded by so much serenity. Perhaps my favorite moments, outside of the general tomfoolery that emerges when 6 young-at-heart individuals combine for 40 days of toil and effort, were those spent with my own thoughts as we bounded across the endless ice sheet like a small convoy of ships crossing an endless sea, buoyed by thousands of years worth of snow and ice all waiting to tell their stories.

Waypoint B11A
[The traverse train trundling along in front of some mountains at GPS waypoing “B11A”.]

This story starts out, however, as a pseudo-survival guide for any would-be ice sheet traveler. If you’re contemplating such a trip, I imagine most of the obvious concerns have already been addressed, such as packing a lot of high-calorie food or outfitting yourself with plenty of puffy and warm clothing. Like this summer’s list of things to do in Hanover, I present, in no particular order, my top 5 things to think about when traversing an ice sheet:

1) Be prepared to be cold. Not surprising, but it bears repeating.

2) Be patient. This goes along with the cold component, but hardly anything happens quickly when you’re waddling around in 8 layers of clothing. Seriously.

3) Try not to sweat. This pairs well with that patience thing, for if you do sweat you’ll definitely feel the cold.

4) Eat. You’re essentially stoking your internal, caloric heater with food, so eat often. Besides, when else can you indulge in over 4000 calories a day and lose weight?!

5) If there’s a plane, get on it. As much as I love the ice sheet, there truly is no place like home. I spent an extra 7 days in Greenland because I did not get on a plane. Silly.

And sunscreen? That ranks right up there with oxygen and a -40 sleeping bag!

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Scientist in Action at Nuuk Basic

This week we had the unique opportunity to visit Nuuk Basic, a low-arctic long-term ecological monitoring station.  The research station is part of the Greenlandic Ecological Monitoring (GEM) program, which also has a station in high-arctic northwest Greenland at Zackenburg.  The goal of the GEM program is to study the effects of climate change on the terrestrial, freshwater, and marine environments of Greenland and more broadly the arctic using “cross-disciplinary” techniques.

Greenland Ecological Monitoring (GEM) program sites

Cross-disciplinary – it is kind of like double narwhalwhat does it mean?

When I think of the term cross-disciplinary, I envision using one set of methodologies (i.e. ecology) to think about and answer questions in a different field (i.e. geology).  Cross-disciplinary may or may not be synonymous with multi-disciplinary, inter-disciplinary, or trans-disciplinary; it may also just be used colloquially as a synonym.   This is one very interesting questions that our Polar Environmental Change IGERT program at Dartmouth College is trying to think about and contribute to the discussion occuring in academia.

Badeso in the foreground (i.e. the lake with Arctic char) and Kobbefjord in the background

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The 2011 IGERT cohort spent one week camping outside of Kangerlussuaq in the same site the 2010 cohort chose last year.  The first things we noticed upon arriving at our campsite were the incredible views of the Russell glacier, the Little Ice Age moraine, and the glacial meltwater lakes.

Google map of the area between the IGERT camp near the Russell glacier and the Kangerlussuaq fjord. Air temperatures drop as you drive up the road from Kangerlussuaq to the IGERT camp and the glacier, perhaps offering a gradient useful for studying climate change and insect outbreaks.

But as a close second we noticed that the woody shrubs at the site were all leafless and brown, and that there were many large Lepidoptera larvae (caterpillars) roaming in search of food.  This place had experienced a recent caterpillar outbreak. The larvae that were left had no more food to eat, and they crawled up our tents and boots or into any warm microclimate.  Northern wheatears and snow buntings came in to camp to eat this easy prey off the tents.  Adult moths also flew around in large numbers and we picked them out of our hair and our coffee.  We identified this Lepidoptera species as Eurois occulta, the Great Gray Dart moth known to defoliate the dwarf birch and grayleaf willow common in Greenland.

Caterpillars ate all of the birch and willow leaves around camp, leaving a brown world.

Eurois occulta larva

Eurois occulta adult

However, the entire landscape was not brown.  Many hillsides with similar aspect and distance from the glacier experienced only moderate levels of herbivory and remained green.  Farther from the glacier, back toward Kangerlussuaq and the fjord, the brown outbreak patches disappeared.  Acting on a hot tip from Mike Avery, a PhD student in Eric Post’s lab at Penn State University, we searched for evidence that caterpillars were attacked by a pathogen – desiccated caterpillar corpses draped in the willow leaves.  We found many of these corpses in non-outbreak areas farther from the glacier but did not see any close to the glacier where air temperatures are much cooler.

Some nearby hillsides, however, suffered only slight defoliation.

Closeup of moderate levels of herbivory.

Carcass of a larva infected by a pathogen.

Why are some hillsides completely brown while others remain green?  This is a big question in ecology, and one possible answer is that caterpillars in defoliated areas lack “top-down” controls by predators such as birds, other arthropods, and pathogens.  The caterpillar immune system can fight off infection by pathogens (fungal or viral) but this defense requires a high protein diet.  In plants much of this protein is RuBisCO, a nitrogen-rich enzyme essential for photosynthesis, and the protein content of leaves is expected to decrease as air temperatures get warmer and the growing season gets longer.  Perhaps caterpillars farther from the glacier had less resistance to pathogens because of lower protein content of leaves, or perhaps there are more natural enemies such as birds or arthropods in warmer areas.  The birch/willow shrub tundra of West Greenland is a great ecosystem to test competing explanations for why insect herbivores sometimes outbreak and how climate change may alter the frequency and intensity of these outbreaks.

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With the greatest effects of climate change expected to be seen in the Arctic, we will likely see major changes in the hydrologic cycle. The lakes in the Kangerlussuaq region of Greenland have unique ecosystems and, because of their great number, play an important role in the surface albedo and local climate of the region.  These lakes are already changing in size and future expansion or contraction of the lake area may result in significant changes in the local water balance, surface albedo, and ecological processes. In order to predict the future changes of these lakes, such as changes in volume, chemical compositions, or ecological processes, we first need to understand the water balance of these lakes and the hydrologic cycle of this region.

There are two main types of lakes around Kangerlussuaq which have different hydrologic regimes. Most of the lakes receive water from precipitation only and because they are in closed basins, lose water primarily through evaporation. The other type of lake is located near the ice sheet and differs from the others by receiving the primary input of water from melting ice, with precipitation playing a lesser role. These inputs and outputs of water are going to be changing as climate change progresses so it is important to understand the current hydrologic cycle before these major shifts occur.

Ben and Sam overlooking meltwater lake

Precipitation fed lakes in Vulgaris Valley

In order to quantify these components of the hydrologic cycle, our group conducted a series of studies on a number of lakes in the Kangerlussuaq region. One of the primary efforts was to collect water samples to be measured for their isotopic composition as the isotopes of water are powerful tools that are used as tracers to understand hydrologic cycle dynamics. In addition, samples were taken to measure the water chemistry, determined the depth of lakes from our boat, identified if lakes were stratified or not, and we used a YSI multiprobe to measure various properties of the water that included temperature, pH, and conductivity. From these measurements, a series of mass balance relationships will be used to best determine the rates of inputs and outputs to these lakes to define a starting point in order to predict future changes.

Sam sampling on dried up lake near camp

The team sampling from boat near the ice sheet

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While Julia and I camped out with the IGERT cohort 2 this last week, Corina Gamma, a documentary filmmaker in Greenland filming for her latest project Warm Greetings, visited us out at camp to get some footage of what the IGERT crew is up to.  In the morning, I was able to chat with Corina, over oatmeal and coffee, about her project and the motivations behind it.

Documentary Filmmaker Corina Gamma

Documentary Filmmaker Corina Gamma

Corina’s film intends to explore two stories occurring in tandem in Greenland during this period of dramatic social and ecological change.  These stories are that of the Greenlandic Inuit, reflecting on their long lasting and strong connection with the land; and that of the scientists studying Greenland, piecing together the picture of the earth’s climate history and it’s future.  Through exploring these two stories together, the film will demonstrate the interconnectedness of these perspectives and attempt to put forward a more complete description of Greenland’s current situation and potential future state.

Corina Gamma interviewing Thomas Overly in front of the ice sheet.

Corina Gamma interviewing IGERT Fellow Thomas Overly

In my mind, both the IGERT program and Corina’s project are two responses to the same question:  how do we overcome the gap between science and public understanding to raise awareness and enact real, sustainable changes?

IGERT fellows, on top of making a commitment to further the body of scientific knowledge in their respective field of study, also have recognized the importance of communicating this research beyond the scientific community and engaging in constructive dialogue surrounding these issues.  One of the main goals of the IGERT program is interdisciplinary learning. And while this goal includes the interactions between students in earth sciences, engineering and biological sciences, importantly, it also means extending the impact and understanding of these research questions into social and political realms.  Just today the IGERT cohort 2 took off on a flight to Nuuk (the capital of Greenland) to spend the week meeting with local residents and key political figures.

During Corina’s visit, it was inspiring to see the confluence of these two approaches to solving the same problem.  Truly an interdisciplinary moment!

For more information about Corina Gamma’s Warm Greetings  project, you can visit her webpage at : http://warmgreetingsthemovie.com/

And to read Corina’s own blog post about visiting the IGERT students, click here.

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