Sunday, May 28, 2017

May 14 Update: Summit to Core 8!

Greetings from the middle of the Greenland Ice Sheet! This is our first deep field post for the 2017 traverse.

On May 6th, 2017 the GreenTrACS team finally departed Summit Station, beginning the science of the second field season of the Greenland Traverse for Accumulation and Climate Studies.  Years of preparation, a week in Kangerlussuaq, and nearly a week at Summit, and we were finally on our way!
Five snowmobiles, 10 sleds, 2 pods, 4 radar systems, gear for 8 weeks of camping, cooking, crevasse rescue, and fixing everything that breaks.  The team was excited to finally have everything packed and get on the road (photo: Grey Davis).
GreenTrACS team before departing Summit Station, Greenland.  From right to left: Karina Graeter, Gabe Lewis, Tate Meehan, Forrest McCarthy, and Hans-Peter Marshall (photo:Grey Davis).
Over the next five days, we travelled 440 km to Core Site 8, the first ice core location this year. We designed our course to follow a few IceBridge lines, and we took radar measurements the whole way. Because we were moving camp every day, we only set up one 12x12 ft Arctic Oven to use as a cook/science/sleep/charging tent. Things were a bit crowded, to say the least. Packing up and moving everyday was extremely exhausting, and we didn't have any personal space/time while we were moving to Core 8.

Hauling heavy loads from Summit to Core 8
During the third day, a storm dumped 10-12 inches of light, fluffy snow on our camp. The wind that night shaped the snow into giant sastrugi, which made our snowmobiling extremely bumpy and unpleasant the next few days. Our snowmobiles and sleds sunk into the thick, soft snow. Everyone got stuck at least once, and we had to dig out the heavy sleds and tow each other out of the piles of powder. When we finally reached Core site 8 on May 10th, we were all extremely happy to set up a real camp and have a bit more space to spread out. Plus, we didn't all have to listen to each other snoring all night!

Beautiful sastrugi after the big storm - lots of fresh powder!!

At Core Site 8, we dug a 1m deep pit to collect snow samples and analyze the snow stratigraphy. HP led a snowpit lesson (he's a snowpit master), while Gabe collected albedo and optical grain size measurements. Afterwards, Karina and Gabe drilled a 30.2 m ice core and placed the core segments into 3 ice core boxes to be transported back to Dartmouth.

Typical field camp: Core 8 Drill Site.
Tate and HP collected radar data along a 30 km spur to the west. Tate's multi-offset radar system seems to be working great, despite the bumps and fresh snow, while HP's FMCW radar is much improved from last year.  They are also running the Dartmouth Engineering Department's GSSI radar system, which is completely solar powered and can run both the 900 and 400 MHz systems simultaneously.

The team at the Core 8 drill site - still looking spy after their long slog from Summit.

Upon arriving at Camp 8, we saw two kite skiers making their way towards our camp. Max and Ulrikke (who we had actually met in Kanger) had kited 11 days and nearly 400 km from Kanger and somehow managed to see our bright yellow kitchen tent among the endless white ice sheet. We offered them hot tea and were thrilled to see their kit skiing setup, hear stories of their sailing adventures all over Europe, and learn a bit about competitive kite skiing. After a few days of rough sastrugi and tiring kiting, they were very grateful to have a place to sit and rest. The wind was forecasted to completely die the next day, so they set up camp nearby and offered to help us cook dinner and dig a snowpit in exchange for much needed company. They even offered to give Gabe a kite skiing lesson (something he's always wanted to try), but were unable to fulfill that offer because a) he just had brain surgery 2 months ago and everyone said that it was a pretty stupid idea to try it this far from a hospital, b) there was no wind to fly the kite.

Karina with a beautiful homemade pizza from the camp oven.

Today HP, Tate, and Forrest are snowmobiling back to Core 7 (the last core site from the 2016 traverse) to collect the weather station and extra fuel we left last year. Miraculously, the weather station seems to have survived the winter and somehow collected hourly data since last June. None of the fuel leaked out of the barrels, so we'll definitely have enough gas to get to Cache 1 later this week.

HP, Tate and Forrest ready for their run to Core 7 to get last year's remaining fuel 
and a weather station that's been recording data for the past year.

We heard that 10-15 congressmen and the head of the National Science Foundation were visiting Kangerlussuaq and Summit Station this week, but we were surprised to hear that they wanted to fly over our camp to see what we were working on. They circled overhead a few times as we waved up to the plane, hoping to make a good impression with our tidy camp and covered snowmobiles.

NSF and Congressional Delegation overfly the Greentracs camp at Core 8.

We plan to move camp to Core site 9 on May 15th. The next day, we will be visited by a twin otter plane that will drop off Bob Hawley and pick up HP. Bob is taking over HP's role for the remainder of the traverse. We will be very sad to see HP go, but we are also a bit jealous of the warm showers and fresh veggies HP will soon enjoy in Kangerlussuaq.

Friday, May 5, 2017

Summit Storms and Work

We've spent the past few days huddled up in the Big House hiding from the storm that ripped through Greenland, with temperatures dipping to -14 F and winds up to 40 knots. Luckily, all of our tents held up and we managed not to lose anything in the wind or under the drifting snow. During Condition 1 weather no one is allowed to travel alone outside, we radio the camp manager each time we're leaving or arriving at a location, and no one can leave the station without a GPS, radio, and emergency beacon.


The Summit Science crew allowed us to use some space inside the Summit Operations Building to prepare our radar sleds and mount various GPS antennas to our snowmobiles. Being allowed to work inside saved us a few days while waiting out the nasty weather. Big thanks to the operations crew!

HP mounts the Frequency Modulated Continuous Waveform radar and GPS to his snowmobile

Tate sets up his Multi-Offset radar in the operations building

HP launches a weather balloon to monitor the temperature, humidity, and wind speed near Summit 

Once the weather cleared, we spent Thursday and Friday building our sleds, organizing our cache loads, and testing the radar equipment. The Twin Otter plane is supposed to spend Saturday and Sunday dropping off ice core boxes, extra food, snowmobile gas, and propane to four locations along our route.

Our "kitchen sled" komatik sled loaded up and ready to move to Core 8

One of our fuel sleds towing the empty ice core boxes

Caches 2 and 3 staged near the runway awaiting the airplane

HP and Tate admire the two radar sleds after their test drive near Summit

After setting up all the sleds and testing the equipment, we were able to to get a tour of the Temporary Atmospheric Watch Observatory. Located 1/2 mile south of the Big House (in the clean air sector), the TAWO measures temperature, wind speed, humidity, incoming radiation, atmospheric black carbon, and other particulates floating around in the air. We walked past the GISP2 borehole, which was one of the main reasons Summit Camp was established in the 1990's. GISP2 drilled down 3053 m through the ice sheet and into the bed rock, the deepest ice core ever recovered at the time. After dinner, Gabe gave a 20 minute science lecture on preliminary results from the 2016 GreenTrACS traverse and our plans for the upcoming traverse.

Gabe gives a science lecture in the Big House wearing his formal Carhartts

Gabe hugs the GISP2 borehole

The Temporary Atmospheric Watch Observatory

Tuesday, May 2, 2017

Summit Preparations

On our last day in Kangerlussuaq we took a trip out the the edge of the Greenland Ice Sheet. The margin of the ice sheet is a stark contrast to where we will be traversing. On our traverse, we will be well within the accumulation zone of the ice sheet, where each year more snow accumulates than melts away. The scenery is snowy, flat, and white, and we stay at higher elevations to avoid crevasse zones. But at the margin we were in the ablation zone, where there is more snow melting than accumulation. There we could see bare glacier ice, thousands of crevasses, and mounds of glacially deposited debris called moraines. It was great to see a little topography before heading out onto the flat white.  

Hiking from the car to the edge of the ice sheet

The edge of the Greenland Ice Sheet

Yesterday we landed at Summit Station, the National Science Foundation research station at the top of the Greenland Ice Sheet. Here, the elevation is 10,528 feet above sea level and the mean annual temperature is -22.2 °F. When we landed the wind chill was around -30 F, so we quickly hurried into the warm Big House to eat some delicious foods. The closest town is Ittoqqortoormiit, 460 km to the east. The station itself is an impressive operation, with about a dozen different buildings for science, logistics, and living spaces. There are currently 25 people (including us) living at Summit, so everyone gets to know each other pretty well. The camp operates year round to collect important weather and atmospheric data for several climate models, luckily we're here when the sun barely sets and temperatures are warm enough to work outside for a few hours at a time. We were excited to arrive on the plane from Kangerlussuaq just before lunch time despite low visibility. After a delicious meal, we set up our sleeping tents and a 12x12 ft science tent, then began sorting through our 4000 lbs. of food and cargo.

Our plane on the snow runway at Summit Station

We are spending the next few days rigging up our sleds and checking our science gear before heading out on the 8 week traverse. Unfortunately the weather hasn't been cooperating very well. Today, despite 25 knot winds and blowing snow, we sorted through our caches (we will be leaving four caches along our traverse route with food and fuel), transferred our snowmobile fuel from 55 gallon fuel drums to 15 gallon polydrums, and mounted the various ground penetrating radar equipment onto our sleds and snow mobiles. The weather and visibility are likely to deteriorate into tomorrow, giving us plenty of time to acclimatize to 10,000 ft (a.k.a. eat all the yummy cookies and candy in the kitchen). Hopefully the weather will improve enough by Thursday that a twin otter plane can land here to pick up gear and cache some of it along the traverse route.

Our gear piled into different caches

Gabe freezing in front of our tents as the wind continues to blow

Forrest hard at work acclimatizing

We definitely feel spoiled starting our traverse at Summit Station. With warm rooms, an amazing cook, electricity, internet, and friendly faces, it's going to be hard leaving here for the barren ice sheet in a few days.

Sunday, April 30, 2017

My day with IceBridge

I've spent the better part of the last two years analyzing data from NASA's Operation IceBridge, a multi-year mission to collect data over both the arctic and antarctic using several instruments mounted to some futuristic-looking custom planes. I was trying to determine how much snow falls across Greenland during the past few centuries using IceBride's Accumulation Radar. I then compared these rates with state of the art climate models across the ice sheet. You can read the abstract, look at the pretty pictures, and skim through the paper here (for free)!

After countless hours analyzing IceBridge data, I was excited when I learned they were spending a few weeks based in Kangerlussuaq flying around the Greenland Ice Sheet. I quickly emailed the project manager to ask if we could meet up for coffee to talk about the mission, but he invited me to join the mission to fly on the plane for a day. I was ecstatic.

After a brief 15 minute safety video (slightly more entertaining than the safety videos on United Airlines) and medical forms, I was allowed to tour the plane and see the instruments.
Stepping onto the P3-B IceBridge airplane

Racks of computers and hard drives collect and store the data inside the fuselage

It took a while to warm up the instruments, check that everything was working properly, de-ice the airplane, and get clearance for takeoff (the Kangerlussuaq airport is surprisingly busy since it flies to Copenhagen and many small Greenlandic villages). We were heading for the Penny Ice Cap on Baffin Island (Canada) to measure the thickness and elevation of the ice cap, take pictures from the bottom of the plane, and calculate the amount of snowfall across the glacier. We flew across the sea ice of Baffin Bay until we started to see gigantic granite cliffs rising from the sea.

Mountains rising out of the sea ice at the eastern edge of Baffin Island

A glacier flows down one of many valleys

Large cliffs dominate the fjords around the edge of Penny Ice Cap
I see why Baffin Island has some of the best (and least explored) rock climbing in the world

Crevasses form in a glacier as it flows across a steep section of rock

The Penny ice cap with mountains rising in the distance

After taking in all the spectacular scenery, I tried to learn a bit more about how each of the instruments work. IceBridge carries 4 laser altimeters (to measure the height of the ground surface directly below and slightly to the side of the airplane), 5 radars (to see the top 20, top 300, and total thickness of the ice sheet), a gravimeter, magnetometer, and various downward mounted cameras to photograph the ice sheet. Using a fancy kinematic GPS the airplane's position and tilt/roll/yaw are known precisely with astounding accuracy. Pilots steer the plane according to predetermined flight paths 1500 m above the ground using iPad-like-devices that look more like a videogame than an instrument you'd find in a cockpit.

I was very excited to be able to fly with IceBridge for a day and learn all about how they operate. I'm continually impressed by the amount of data they are able to collect during each field season, and the quality of each instrument. Hopefully I'll be able to fly with them again soon.

Scientists control various instruments towards the back of the plane

The pilots look out over the sea ice in Baffin bay

Wednesday, April 26, 2017

We made it to Kangerlussuaq!

Yesterday HP, Forrest, and Tate flew from New York to Kangerlussuaq, Greenland. This is the first time that we are all together as a team!

Our flight to Kangerlussuaq was on a C-130 plane with skis
Karina trying to stay warm and catch up on sleep during the plane to Greenland
The traverse team consists of Karina Graeter and Gabe Lewis from Dartmouth College, Tate Meehan and HP Marshall from Boise State, and Forrest McCarthy (an all star mountaineer and safety rescue guru). A few weeks into the traverse, HP will be leaving and Bob Hawley (also from Dartmouth) will join us out on the ice for the remainder of the campaign.

Today we got busy with traverse preparations. The morning started out with a snow mobile and generator maintenance meeting. We are taking 5 snowmobiles out onto the ice with us. Three are 2-stroke machines (older and more powerful, but not comfortable to ride), and two are 4-stroke machines (newer, more fuel efficient, but complicated to fix if they brake down).
Forrest and HP taking a look at the snow mobiles. HP is working on mounting the ground penetrating radar antenna to the side of this snow mobile.

We spent the rest of the day organizing our gear. Polar Field Services did an awesome job getting much of our gear ready for us and storing items from last season. We set up and double checked all of our tents, sleeping cots, stoves, and kitchen gear. Tate and Karina washed up all the cookware, dishes, and tables to get them ready for the ice after they collected a bit of dust this winter. We organized our food into boxes to take with us at the beginning of the traverse and three cache sites (at Cores 9, 12, and 15) to be dropped off with extra snowmobile fuel next week. We hid Poptarts in each cache box so that we don't eat them all during the first week!

Some of our gear in the warehouse
Gear allocated to us by Polar Field Services including tents, cots, survival kits, medical kits, and tarps among many other items.

Tate and Karina washing the kitchen tables

Over the next few days we plan on packing up all our gear onto the ten (ten!) sleds we will be pulling alongside the two safety pods. We want to make sure that we can securely and neatly pack up all the science gear, personal gear, food, and fuel we will need for the next two months. Additionally, we will have meetings about safety and communication check-ins. If everything continues to run smoothly, we should have a day to rest up before heading up to Summit Station on May 1st!

We'll keep you updated on how the preparations progress!

Wednesday, April 12, 2017

2017 Field Itinerary

It's been a busy few weeks here at Dartmouth prepping for the 2017 field season. Karina and Gabe spent a few hours at BJ's and Hannaford's buying all the food for 5 people for 8 weeks on the traverse, then many more hours repackaging and sorting everything so that we minimize the amount of time we spend looking through the bins for pancake batter on storm days. We made sure to buy twice as many Poptarts as last year, so we shouldn't have a shortage this time!

Karina holds the receipt and shows off all the food we purchased at BJ's, doesn't it look healthy!

We tested the GPSs, radar systems, ASD albedo measuring device, new laptops, satellite internet connection, satellite phones, and Karina's new Canada Goose jacket (all the old ones were way too large for her).

Gabe got some funny looks testing the satellite internet outside of the Earth Science building as class was just letting out

Over the winter, Gabe worked on a paper calculating accumulation across the interior of the Greenland Ice Sheet based on airborne radar from NASA's Operation IceBridge. After publishing the study (link here) we realized there was a large gap between the coastal weather stations and regions where airborne radar could calculate accumulation. We decided to traverse through this gap to take the most useful measurements.

2016 GreenTrACS traverse (blue) and 2017 route (red) on top of a NASA Operation IceBridge accumulation radar measurements 
During the 2017 field season, we will snowmobile clockwise from Summit, Greenland (where we finished our 2016 traverse), along a 1200 km main traverse path, with an additional 1200 km of E-W spur radar lines. Karina and Gabe plan to drill 9 ice cores (hopefully 20-30 m deep again this year), while Tate, HP, Bob, and Forrest collect radar measurements. Gabe received another grant from ASD to bring a FieldSpec4 to measure albedo, and Bob has promised to fix the downward looking laser to measure surface roughness before the start of our traverse.

Karina and Gabe will fly to Kangerlussuaq on 4/18 to prepare. On 4/25 Tate, HP, and Forrest will join in Kanger to prepare for the traverse. The entire team will fly to Summit on 5/1 and spend a few days acclimatizing and testing all the scientific gear in the very cold conditions.

A detailed view of the 2017 field traverse

We'll spend a few days snowmobiling from Summit to Core 8, trying to maximize the radar data quality along this ~400 km section. Once we all reach Core 8 the real science begins. Karina and Gabe will drill their first ice core together, a team will drive west to collect radar measurements, and someone will return to Core 7 to collect the weather station we left there last season.

Bob will fly to Greenland April May 15 and join the rest of the team a few days afterwards. He will bring news from the states, fresh vegetables, and hopefully a birthday cake for Gabe! HP will then fly back to Idaho to resume his teaching and research responsibilities.

Just as last year it will take a few weeks to work out all the kinks and begin to click together as a team, but we are all looking forward to the science and opportunities we'll have this season.

Case Study: Is Greenland Getting Darker?: National Science Foundation-Sponsored Research Project Uses ASD Instruments to Measure Climate Change

Full article at

Written by Melissa Christensen, ASD

Case Study: Is Greenland Getting Darker?: National Science Foundation-Sponsored Research Project Uses ASD Instruments to Measure Climate Change


The Greenland ice sheet has experienced a recent period (since ~1990) of accelerating glacier melting, causing global sea level rise. Along with warming Arctic temperatures, Greenland’s melting may have been enhanced by a darkening snow surface, but scientists haven’t been able to determine if, and why, Greenland’s snow is getting darker due to the expense and difficulty of getting researchers out in the field. A darker snow surface absorbs solar radiation more quickly, warms up, and causes melting. The necessary research would focus not only on how much snow is falling, but also where it’s snowing, how much snow is melting, and whether and why the snow surface is darkening. The end goal is to determine how far sea level will rise in the next few decades to centuries, threatening many of America’s major coastal cities.


In 2016, a collaborative research group from Dartmouth College, The University of Maine and Boise State University, Idaho, sponsored by the National Science Foundation (NSF), began studying the recent changes in surface mass balance on the western Greenland ice sheet percolation zone. The research project includes two field seasons snowmobiling ~3000 km across Greenland to investigate how the massive ice sheet is changing and why.

In order to gather crucial data, Gabriel Lewis, Dartmouth College Ph.D. candidate, wrote a NSF Graduate Research Fellowship grant, as well as a Goetz Fellowship Grant from ASD, to borrow an ASD FieldSpec® 4 spectroradiometer and was awarded temporary use of the instrument for both field seasons.

“We knew we needed to measure albedo to find out if Greenland is getting darker as a result of more impurities from fossil fuel pollution in the snow, or if the darkening is from larger snow grain sizes from warmer temperatures, or if the satellite measurements are falsely indicating a darkening ice sheet,” said Lewis.

Lewis chose the ASD FieldSpec 4 because:

Unlike other spectroradiometers, the FieldSpec 4 can measure albedo (the ratio of incoming and outgoing radiation of the snow) at multiple frequencies (in this case, 350-2500 nanometers with high resolution and accuracy) for a more complete picture.

The FieldSpec 4 can also be used with a contact probe to measure the optical grain size of snow grains – a vital piece of information to determine if the snow has darkened.

The instrument is portable, making it easy to transport and use in the field.

The instrument came highly recommended by engineering colleagues at Dartmouth College.

The FieldSpec 4 instrument was used to measure albedo, as well as the optical grain size of the snow. Additionally, samples of snow were collected and analyzed to measure their dust and soot impurities. Through laboratory analysis back at Dartmouth, the group was able to measure the quantity of impurities, their origin and whether their creation was natural or man-made.


Though the research project has yet to be completed, the preliminary results exhibit a statistically significant correlation between the snow grain size and albedo, and no statistically significant correlation between the impurities and albedo. There is great agreement between the NSF-sponsored research project’s measurements and both NASA satellites and computer climate models. Most of the measurements fall within the expected uncertainty from the samples and locations processed so far and the team is eager to collect more data.

“It’s great to know we are on the right track. I am very excited to take the FieldSpec 4 back into the field this spring and expand on some of the correlations we’ve already noticed,” commented Lewis. “From my work last summer, it is clear the ASD FieldSpec 4 albedo measurements in Greenland agree nicely with many of the satellite and climate model measurements -which is wonderful.”

In April 2017, Lewis and his team will return to Greenland to gather additional measurements over the course of eight weeks. From there, the final research data will be compiled to determine whether or not current climate models need to be altered to better predict the future of the Greenland ice sheet, including what is specifically causing the snow to melt or become darker (e.g. grain size, pollution, warmth, etc.).

Lewis concludes, “climate change is not up for discussion. It is real. It is happening, and we have all the data to prove it. The data I am helping to gather and analyze will help us understand the impact of climate change on Greenland, and what it means for the future of the planet.”