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Greenland Aquifer Expedition: What about a round-trip cargo flight?

April 1st, 2014 by Maria-Jose Viñas

By Ludovic Brucker

Kulusuk, 29 March 2014 — For our deployment to the field, we need two flights to bring our scientific equipment and camping gear. As mentioned in our previous post, we decided to avoid being on the ice sheet while the third storm system of the week affects the area. However, thanks to Air Greenland and its helicopter B-212′s crew, we were able to have a first cargo flight to the ice sheet on Thursday afternoon. This will allow us to be fully operational as soon the second flight brings our tents, food, more science gear, and us to the ice sheet!

Thursday morning, we went to the airport to meet with the pilot and hear his point of view about a possible cargo flight that same day. While snow-removing activities of the runway were underway, he shared with us his concern that our cargo (if left on the ice sheet with the current weather system developing offshore) may be blown away or heavily buried in snow. Since we did not have a single item fly away in Antarctica during our SEAT 2011-2012 traverse and its Christmas storm, we will make sure this does not happen in Greenland! Regarding buried items; it’s fine as long as the shovels aren’t buried themselves.

Machinery removing snow  at the Kulusuk airport. (Credit: Ludovic Brucker.)

Machinery removing snow at the Kulusuk airport. (Credit: Ludovic Brucker.)

A snow plow removes snow from the second storm of the week at the Kulusuk airport . (credit: Clément Miège.)

A snow plow removes snow from the second storm of the week at the Kulusuk airport . (credit: Clément Miège.)

In the afternoon, Clem and I took off with the cargo flight to unload it from the helo, and to build the cargo line. The sky was scattered with clouds, sometimes low, but it cleared up as we were approaching the ice sheet.

Transit from Kulusuk to our ice sheet location, near the settlement of Tinitequilâq. (Credit: Ludovic Brucker.)

Transit from Kulusuk to our ice sheet location, near the settlement of Tinitequilâq. (Credit: Ludovic Brucker.)

Approaching the ice sheet's edge with the B-212 helicopter. (Credit: Clement Miège.)

Approaching the ice sheet’s edge with the B-212 helicopter. (Credit: Clement Miège.)

Approaching the ice sheet's edge with the B-212 helicopter. (Credit: Clement Miège.)

Approaching the ice sheet’s edge with the B-212 helicopter. (Credit: Clement Miège.)

Flying over the Greenland ice sheet. (Credit: Ludovic Brucker.)

Flying over the Greenland ice sheet. (Credit: Ludovic Brucker.)

We landed in the vicinity of our temperature probe system and its Argos antenna, which has been sending temperature measurements every day for almost a year now. With the help of the helicopter’s crew, it did not take long to organize a cargo line along the dominant wind direction to minimize snow drift.

Our cargo line on the ice sheet, near the temperature probe and Argos antenna we left behind in 2013. I'm finishing up by deploying a second cargo strap across the line and through the boxes handles. (Credit: Clément Miège)

Our cargo line on the ice sheet, near the temperature probe and Argos antenna we left behind in 2013. I’m finishing up by deploying a second cargo strap across the line and through the boxes handles. (Credit: Clément Miège)

Our objective was accomplished, the cargo was on the ice sheet. Step 1: Done! Done? Well, of course not. We still had to fly back… But in spite of everyone’s effort, we were not able to fly back to Kulusuk that day. The night was coming quickly and the pilot is not allowed to fly after twilight. Thus, we landed in Tasiilaq 3 minutes after twilight on Thursday. Tasiilaq is on the other side of the bay from Kulusuk, a 15-minute helicopter ride away. Tasiilaq is the largest city on the East coast of Greenland, with about 3,000 inhabitants, and it’s home for the B-212. We landed accurately on the B-212′s kart in front of its hangar so that it could be moved inside quickly. Suddenly, Clem and I were facing a situation for which we were not prepared.

Descending to Tasiilaq. (Credit: Ludovic Brucker.)

Descending to Tasiilaq. (Credit: Ludovic Brucker.)

For a less-than-2-hour round trip to the ice sheet, Clem and I were dressed in our warmest layers, and to face a variety of eventualities (including spending an unexpected night on the ice sheet) we had packed a tent, sleeping bags, food, water, extra jackets, gloves, goggles and hats, a satellite phone, two GPS, and a beacon locator. We knew that in our cargo there was more food, a cook stove, propane and white gas; these were in case for the inbound flight. For the outbound flight, we knew that the B-212 has some safety equipment too. That was all we had. But we were facing a different situation now: we were in the largest town of East Greenland, with the perspective of a storm arriving overnight, and forecasted to last several days.

Air Greenland found us a hotel and a warm dinner. Sweet, we wouldn’t be camping on the helipad. Past the first night, we woke up with the exact same landscape as in Kulusuk. I’m serious! Through the windows we could see the same white sky, land, and horizontal snowfall. Visibility? We still don’t know for sure; neither Clem nor I could tell because we had left Kulusuk with our contact lenses on and did not carry our glasses.

Past this first reality check, we headed to breakfast (dressed in our long underwear). We had a specific topic to discuss: what were we going to do during the next hours, days, week? The ideas ranged from finding a book, a toothbrush, an Internet connection, an alternative to water for our contact lenses, learning Greenlandic, finding a boat… Three hours after breakfast, we started a hunt for a set of playing cards to play cribbage. I asked the hotel manager if we could borrow cards from the hotel, or any other game that would keep us busy a few hours, days, a week. He pointed out a souvenir store where we could buy such items. Well, despite knowing that one should take his passport to the field, we did not have money. The hotel manager had a swift idea: “That’s not a problem, you can wash dishes after lunch.” Good times! So, we registered for being the little hands in the kitchen. The next 15 minutes were funny, I was trying to explain this to Clem, and to convince him that it was no joke at all. After lunch, we would be on dish wash duty, dressed in long underwear, and without glasses.

I left for a minute to go back to the room and heard Clem running toward me: “Dress up, we are leaving! The helicopter will take off within the next hour. We must go the airport right now.” Ha, ha, funny Clem, you thought I was joking with washing the dishes, and now you feel the need to make a joke too, but I ain’t a silly fool, and it’s not April 1st yet. Well, when I saw Clem dressing up, and tightening his shoes in a hurry without wasting time to comment further on his statement, let me tell you, I quickly dressed up too! I could not risk missing that flight, if it happened.

Air Greenland was able to fly us back to Kulusuk using a French-made helicopter (an Ecureuil – an Astar helicopter) flown by an Icelandic pilot. Certainly, he was used to windy conditions, and low visibility. We were reunited with Rick for lunch in Kulusuk!

We would like to thank Air Greenland for their dedication to serving our project yesterday and today.  Working with us on a flexible schedule to get the cargo flight in yesterday was a big help. Accommodating us in Tasiilaq and getting us back to Kulusuk this morning allowed us to be ready for the next opportunity to fly to the ice sheet so we can begin our experiments. A continued good relationship with Air Greenland and their pilots is important for the success of our science. We view them as team members critically needed to move forward with a successful campaign.

Greenland Aquifer Expedition: Flying tomorrow? Opa!

March 31st, 2014 by Maria-Jose Viñas

By Clément Miège

Kulusuk, 26 March 2014 — “Opa” is a Greenlandic word for “maybe”, as we learned it this morning while talking to Danish guests at the hotel Kulusuk who have been stuck for a few days due to bad weather.

To give you a little bit of background, the southeastern part of Greenland witnesses the highest precipitation rates of the island, in conjunction with strong winds (either from the ocean or the ice sheet). Often, the weather is unpredictable, especially at this time of year. Therefore, conducting fieldwork in southeast Greenland is a gamble.

Last year, when we experience really great weather in Kulusuk the week before our field work, we did not fully realize how lucky we were to be able to go to the field as scheduled. This year, it has been a different story: we have already gone through two storm systems, and yesterday night a third storm hit us, with a lot of wind and snow. We feel like we are paying the price of last year’s fantastic weather.

That being said, this weather is good to prepare the cargo for our flights to the ice sheet. We spent a good part of Sunday getting the low-frequency radar system ready. We worked on the radar sleds, as well as on the tube that will keep the radar antenna straight when we drag the system on the snow surface.

Ludo and Clem, working on gluing the coupling made to connect the radar antenna tubes. (Credit: Rick Foster.)

Ludo and Clem, working on gluing the coupling made to connect the radar antenna tubes. (Credit: Rick Foster.)

: Ludo, fixing special bindings on the skis to attach the radar box to them (Credit: Rick Foster.)

Ludo, attaching special bindings on skis to attach the radar box to them (Credit: Rick Foster.)

On Monday, we went to the village of Kulusuk to buy some supplies (we are currently staying in a hotel that is about a 30-minute walk from the village). On our way to the village, we saw four teams of dog sleds ready to leave for Apusiaajik glacier. The dog sleds are carrying skiers and a week-worth of their base camp materials, so the skiers can enjoy the fresh snow!

A dog sled getting ready to leave. (Credit: Clément Miège.)

A dog sled getting ready to leave. (Credit: Clément Miège.)

We walked around the village to get some nice views of the ocean and the sea ice. As we were walking, Ludo made a local friend! A Greenlandic kid who was a really fun guide and gave us a tour for an hour. At some point, we realized that he was always avoiding the direction of the school!

A young Greenlandic musher, showing Ludo which way to go! (Credit: Clément Miège.)

A young Greenlandic musher, showing Ludo which way to go! (Credit: Clément Miège.)

Rick in front of the broken and refrozen sea ice. Imagine how different it is from the open ocean in the summer, with boats cruising around.  (Credit: Clément Miège.)

Rick in front of the broken and refrozen sea ice. Imagine how different it is from the open ocean in the summer, with boats cruising around. (Credit: Clément Miège.)

After that, we went to the store and got some food and a propane tank for our stove on the ice sheet. We found everything we needed and headed back to the hotel. We finished the day at the airport further organizing the science equipment.

Rick works on an extension of the ARGOS antenna mast that we already have installed in the field. (Credit: Clément Miège.)

Rick works on an extension of the ARGOS antenna mast that we already have installed in the field. (Credit: Clément Miège.)

Tuesday, Ludo and I went back to the airport warehouse and finished organizing the cargo for the helicopter flights. We’ve prepared two distinct: one consists of our camp gear, sleep kits, food, personal gear, and some science equipment. The other (which can arrive later), is composed by the rest of the science gear.

Wednesday has been different, and we thought it would be “fun” to walk you through the steps that we have gone through today in terms of decision-making:

In the morning, Thursday’s flight is still ‘opa’. We are optimist and getting ready to leave, packing personal bags and organizing the last bits of equipment.

Weather forecast, from the Danish Meteorological Institute, for today Wednesday (March 26) and Thursday (March 27). The good weather window is for Thursday.

Weather forecast, from the Danish Meteorological Institute, for today Wednesday (March 26) and Thursday (March 27). The good weather window is for Thursday.

2 pm: The weather is not improving much and we start wondering if we will still be able to leave tomorrow. According to the forecast, a break in the storm system is still possible for tomorrow, but we would need it to last for at least a couple of hours, so that we can have one or two helicopter rotations from Kulusuk to our camp on the ice sheet. Each helicopter rotation takes about 2 hours.

3:15 pm: We receive an email from our project manager, based in the US. The helicopter company (Air Greenland) advises us not to leave for the ice sheet tomorrow since an extreme storm is coming for the next days and our team will be incapacitated (meaning that we will not be able to leave the tent for four to six days). This email is worrying us further, and we do not need to be trapped in a tent on the ice sheet without being able to do any work. It is a difficult decision to make, since the weather will be good tomorrow. Moreover, if we leave, we would be able to start working as soon as the storm passed and not be risk further delays in getting to camp, since the helicopter might be needed for other important duties, like resupplying villages. We have to balance the pros and cons — put simply, we have to balance spending four to six days in a tent doing nothing but trying to stay warm vs. gaining about half a day of work, since that way we would not need to wait for our put-in flight. After an intense discussion involving our partners and the weather office, we finally decide that we will not fly tomorrow.

Left: Rick, calling with the satellite phone, using a homemade extended antenna (credit: Ludo). Right: Ludo and Rick waiting to hear back from Air Greenland about tomorrow’s flight. (Credit: Clément Miège.)

Left: Rick, calling with the satellite phone, using a homemade extended antenna (credit: Ludo). Right: Ludo and Rick waiting to hear back from Air Greenland about tomorrow’s flight. (Credit: Clément Miège.)

4 pm: Our flight for tomorrow is officially canceled.

7 pm: Even if it does not make any sense to have a passenger flight tomorrow due to this upcoming weather system, we think that it will be really valuable to have a cargo flight to drop our equipment. Hence, only one helicopter load will still need to be transported when the storm is over. We’re still working on this option.

We are not sure when we will be flying, but at least we are ready. Please keep your fingers crossed for some good weather. More updates soon, opa!

All the best from snowy Kulusuk!

Greenland Aquifer Expedition: We Made It To Greenland!

March 24th, 2014 by Maria-Jose Viñas

By Clément Miège

YAY! We made it to Kulusuk on Saturday afternoon! It ended being a not-too-long journey, since all of our flights were on time.

Rick, Ludo and I followed different itineraries. Rick left Salt Lake City on Friday morning and a red-eye flight took him to Keflavik International Airport in Iceland. He landed early Saturday and took a bus from the international airport to the domestic airport in Reykjavik (an hour-long ride).

Ludo came from a meeting in Switzerland and arrived in Iceland late Friday night. He stayed at a nearby hostel in Keflavik. The next day, he was told to take a bus that would take him to the domestic airport and that supposedly departs every hour in the morning. After waiting for a while, with no bus in sight, he walked back to town (carrying 2 duffel bags, a ski bag, and 2 carry-on bags) and learned his first Icelandic words: Saturday and Sunday (laugardaga og sunnudaga.) Turns out, during the weekend, the bus schedule is different. Good thing that taxis were not too far and that he ended up making it on time for his 12:45 pm Greenland flight!

Me, I had a one-day layover in Reykjavik, which was a nice chance to rest a bit and quickly visit the city. I walked around town, not for too long because it was definitely cold and windy and I am not yet acclimated to cold temperatures — but I will be in the next few days!

Reykjavik is a nice city… when it’s not too windy. The day I arrived, the wind was gusting and it was just too cold. But I still went on a walk to check the Hallgrímskirkja church. This is the largest church in Iceland, an amazing structure! Inside, there is a lift, making the church a pretty sweet observation tower with nice views over the city.

[Note: Originally in this post, I erroneously said Halgrímskirja is a cathedral. Thanks to our reader Harry McKone for spotting the mistake!]

On the left, the cathedral with the statue of Icelandic explorer Leif Eriksson. This story explains the first discovery of North America by a Viking expedition, led by Leif Eriksson about 500 years before Columbus: http://www.history.com/news/the-viking-explorer-who-beat-columbus-to-america. On the right, downtown Reykjavik, composed of colorful houses. (Credit: Clément Miège)

On the left, the church with the statue of Icelandic explorer Leif Eriksson. This story explains the first discovery of North America by a Viking expedition, led by Leif Eriksson about 500 years before Columbus: http://www.history.com/news/the-viking-explorer-who-beat-columbus-to-america. On the right, downtown Reykjavik, composed of colorful houses. (Credit: Clément Miège)

The next day, I joined Ludo and Rick at the domestic airport (they both arrived before me). Useless to say that we had a lot of gear between the 3 of us, a total of 6 carry-on bags (including laptops, radar computer, transmitters, GPS, etc.), 5 checked bags (with our cold weather gear), and 2 ski bags. We were a bit scared at first by Air Iceland’s policy of only allowing one 5kg carry-on and a 20kg checked bag per person, but we ended up getting through easily, which was a relief!

Icebergs trapped in sea ice (Credit: Ludovic Brucker)

Icebergs trapped in sea ice (Credit: Ludovic Brucker)

The flight was smooth and fast, only 2 hours to get to Greenland. Approaching Greenland, we started to see more and more winter sea ice along with some big icebergs trapped within it, which is always very pretty. The first islands finally appeared and we were about to land on one of them, where the little town of Kulusuk is.

Interestingly, the sea ice in the fjord next to Kulusuk seemed weaker and it might be thinner this year than when we visited last year. Ludo noticed some spots that were already ice free (see the photo below); those spots were covered by sea ice last April. The wind redistribution of the sea ice and the warm temperature in Kulusuk in January might be the reasons for this weaker sea ice pack.

View from the plane of the sea ice around Kulusuk  (the little black dots are houses.) (Credit: Ludovic Brucker)

View from the plane of the sea ice around Kulusuk (the little black dots are houses.) (Credit: Ludovic Brucker)

Our plane, freshly landed at the Kulusuk airport, with a faint sun halo in the background. (Credit: Rick Foster)

Our plane, freshly landed at the Kulusuk airport, with a faint sun halo in the background. (Credit: Rick Foster)

Shortly after landing, we made it to our hotel, and started to unpack. This year, Ludo and I brought back country skis, which is a really nice and fun improvement, and also a faster way to get from the hotel to the airport, or to go to the old garage where some equipment is stored from last year.

Ludo, getting ready in front of the hotel to ski to the airport. (Credit: Clément Miège)

Ludo, getting ready in front of the hotel to ski to the airport. (Credit: Clément Miège)

At the airport warehouse, we found all the equipment that we sent from the U.S. We counted the boxes and, great news, everything had made it her, and was in pretty good shape too! We started to unpack some items and took some of them to the hotel for re-organizing them some more.

At the Kulusuk airport, Ludo moves equipment around to consolidate our cargo (left). Some equipment is ready to be loaded on the helicopter (right) to go to our field site, but other gear needs some repacking, which will be one of our main tasks for the coming days. (Credit: Clément Miège.)

At the Kulusuk airport, Ludo moves equipment around to consolidate our cargo (left). Some equipment is ready to be loaded on the helicopter (right) to go to our field site, but other gear needs some repacking, which will be one of our main tasks for the coming days. (Credit: Clément Miège.)

Today, a big storm is here and it’s a white-out outside — crazy, brrrrr! It is snowing horizontally. So happy we are not in the field right now! It is really windy this morning, about 37 mph, so we have decided to work indoors. We have couple projects: preparing antenna tubing for the low-frequency radar, preparing the radar sleds, assembling the ARGOS antenna pole, and starting to pull out the equipment from our last year’s storage place.

I can’t take any photos today, since it’s just white everywhere and impossible to see the surrounding buildings.

We are still on track for leaving this Thursday (March 27) to go to our camp site on the ice sheet. Amazingly, the only day of the week that looks good for flying out is Thursday — see the forecast below. That is lucky for us!

According to the Weather Channel, the only day with good weather this week is Thursday -- good thing we are scheduled to leave then!

According to the Weather Channel, the only day with good weather this week is Thursday — good thing we are scheduled to leave then!

I’ll send a new blog post in a few days, stay tuned!

Greenland Aquifer Expedition: Greenland firn aquifer expedition: Season two!

March 19th, 2014 by Maria-Jose Viñas

By Clément Miège

Hi there! I am Clément Miège, a Ph.D. student at the University of Utah and I am going to take you along with us to our second expedition to the southeast region of Greenland, to investigate the physical properties of a firn aquifer. And what is a firn aquifer, you might be wondering? It’s a reservoir of perennial water (that is, water that doesn’t freeze in the winter) that is trapped within the compacted snow layer (or firn) of the Greenland ice sheet. If you didn’t follow last year’s edition of this expedition and/or you want to learn more about the firn aquifer, here are some readings I recommend:

  • Our team’s blog posts from last year will give you some background material on the set-up of the expedition and work over the ice sheet. It describes the travel to our field site in Greenland and the techniques we used on the ice sheet to do a first measurement of the volume of water within the firn aquifer.
  • To complete this story, my team and other researchers recently published a journal article where we described how this aquifer was serendipitously discovered in the spring of 2011 when we were sampling regions of high snow accumulation. The paper also describes how we first mapped the aquifer using a combination of firn cores, ground radar and airborne radars.
  • Finally, we published another journal article following up on the blog posts from last year and determining the volume of the water trapped in the firn aquifer at a specific location. We obtained this volume by comparing the mass of a wet firn core taken inside the aquifer to a core taken in an neighboring area of dry snow. If you assume this water volume is constant throughout the entire firn aquifer (which spreads over an area larger than Western Virginia!), that would correspond to 140 gigatonnes of water stored. To say it in a different way: if the water runoff the ice sheet, it would raise sea levels worldwide by 0.016 inches (0.4 mm).
  • And if you don’t feel like reading scientific papers right now, NASA put out a story about our findings, too.

We are now getting ready for another expedition to Greenland to further monitor the firn aquifer. This year, our four main tasks will be to maintain our equipment currently in place (which performs temperature measurements), collect additional measurements (with a radar), install a weather station, and try traditional ground-water techniques to date the water and calculate its permeability. I will explain in future blog posts why these measurements are important.

I will be part of a smaller team this year, since only three out of the five members of the first-year team are joining. Rick Forster and I will represent the University of Utah, while Ludovic Brucker comes from NASA Goddard Space Flight Center.

The Greenland Aquifer team in 2013.

The Greenland Aquifer team in 2013.

Here is the photo of the team from last year, from left to right; Jay, Ludo, Rick, Lora and I. Lora and Jay won’t be coming to the field this year (we sure will miss them!) If you want to know a bit more about each team member (current and former), you can check this blog post from last year.

Even when we haven’t set a foot in the field yet, the expedition to Greenland started about two months ago with organizing the logistics. Logistics can sometimes be underestimated, but it takes a lot of effort prior to getting to the field to prepare and test the scientific equipment and other field supplies, such as camping gear, food, and power sources.

For this expedition, all of the science equipment (GPS, radars with different frequencies — 5MHz to 400MHz–, piezometers, ice-core drill) was gathered from different institutions in Utah to be packed here and shipped to Kulusuk. Most of the non-perishable food and camping gear was left for over-winter storage after last year’s expedition in a warehouse in Kulusuk, to save on shipping costs.

On March 3 this year, the Utah gear left for Greenland; we’re talking about 800 lbs. of gear that left Salt Lake City on a truck headed to the JFK airport in New York, where it was flown to Reykjavik (Iceland) and then to Kulusuk (Greenland). We got a phone call early this week from our shipping company to confirm that all our equipment made it to Greenland — great news!

Gear packed at the office (left) and ready to leave the shipping facility at the University of Utah (right). We will see this gear again in Greenland!

Gear packed at the office (left) and ready to leave the shipping facility at the University of Utah (right). We will see this gear again in Greenland!

These last days have been really busy, gathering the last items for our science research, and also personal equipment. Yesterday, I was working at Blue System Integration in Vancouver, BC with a colleague, Laurent Mingo, who is developing IceRadar, an ice-penetrating radar system for the scientific community (see this website for additional info). Laurent has been working on an experimental beta version of the current radar that will allow us to penetrate through the firn aquifer to try to image the bottom of the aquifer gradually transitioning from water-saturated firn to ice.

Even if most of the scientific equipment is already shipped, there are always some last-minute important items that we end up adding into our suitcases (like the low-frequency radar). As a brief anecdote, last year, Rick traveled with a pelican case as a checked bag – inside, there was a bunch of wires hooked up to a datalogger. We were aware that it looked kind of suspicious, so it was a bit scary to go through customs with it! Me, I traveled with a 60-meter long thermistor string weighing over 50 lbs. in my checked bag, because the fabrication and calibration took longer than expected and we weren’t able to ship it ahead of time with the rest of the equipment. This year, luckily, most of the heavy equipment was ready on time and we are carrying only a couple random items in our checked bags.

We are starting our journey this week, leaving the U.S. on Thursday evening for Reykjavik, the capital of Iceland. After a day in Reykjavik, we will leave mid-Saturday on a 2-hour short flight that will take us to Kulusuk, Greenland. We are hoping for good weather; last year, Ludo and I “boomeranged” on our first try due to poor visibility at the Kulusuk runway.

In this old map from the US army (from 1941) you can see the location of the small city of Kulusuk in Southeast Greenland (red star), just below the Arctic Circle (~66.5°N). Our field camp on the ice sheet is represented by a white star. The map can be found at the Polar Geospatial Center.

In this old map from the US army (from 1941) you can see the location of the small city of Kulusuk in Southeast Greenland (red star), just below the Arctic Circle (~66.5°N). Our field camp on the ice sheet is represented by a white star. The map can be found at the Polar Geospatial Center.

Kulusuk is our first stop in Greenland. We will be staying at this small village for a few days in order to re-pack our field gear, test that everything is working well (stoves, generators, tents, science equipment, etc.) before going to the field. If we are lucky, we might see one of the polar bears that sometimes come close to town in this time of year.

Colorful houses make up the town of Kulusuk in Southeast Greenland. The shores of the fjord are covered by sea ice in the winter.

Colorful houses make up the town of Kulusuk in Southeast Greenland. The shores of the fjord are covered by sea ice in the winter.

After a couple of days, we will be heading to our fieldwork location on the ice sheet. A helicopter from Air Greenland will drop us and our cargo at our study site; it will be an about 45-minute commute.

That is it for this introduction; our next blog post will be from Greenland!

All the best,

Clément

Greenland Aquifer Expedition: Tracking Temperatures in the Aquifer

April 24th, 2013 by Maria-Jose Viñas

By Clément Miège

Hi there! Today I have another story to share with you! It’s about the tracking of the temperature evolution of the firn aquifer temperature by using two thermistor strings that we set up in the two holes made by Jay (see Jay’s post on drilling for details).

By tracking temperatures over a year, we will observe the firn heating mechanisms in the summer with the melt from the surface of the ice followed by water infiltration in the firn. In the winter, we will get a sense of the refreezing processes from the cold surface air, which cools the upper part of the firn and we will observe the persistence of the firn aquifer over the years.

To achieve this, we installed two thermistor strings with two different lengths: 30 and 60 meters. The shorter string has 60 sensors on it, sampling every half-meter. The longer one will only get a temperature reading every 2.5 meters but it will record deeper temperatures. Both strings are set to collect data every hour for an entire year, assuming the batteries last that long (hopefully!) The temperature chain is called a thermistor string because each sensor is a thermistor, a type of resistor sensitive to temperature changes. After measuring a resistance change, calibration curves allow us to retrieve temperature changes.

The thermistor-string story started in Utah, when we received the equipment late from the manufacturers, giving us only 5 days to work on it before leaving for Greenland. We realized that integrating the whole system together with the satellite uplink would take most of our last prep days.

It was definitely too late to ship the thermistor equipment with the rest of our gear, so Rick and I traveled with it in our checked luggage! I ended up with a 50 lbs of spool coiled with about 60 meters of cable in a suitcase. Rick had a black pelican case as his checked bag, with the second thermistor string, datalogger, ARGOS antenna and other pieces of hardware. We learned how to travel light, bringing minimal clothing, and wearing the cold-weather clothes in the airplane so we were able to meet the airline luggage restrictions – it definitely made for fun travels!

At the Kulusuk Hotel, in southeast Greenland, we finished integrating the thermistor string, mostly by picking the right data-transmission rate to the satellite in regards to our battery consumption estimates. Having the ARGOS satellite uplink will let us receive temperature data via email every day from the field site and tell us almost in real time what the temperatures are in the two holes.

In the field, shortly after drilling each hole (to avoid water refreezing due to cold air down the hole), we lowered the thermistor string down and backfilled the hole with surface snow. Then, we used the Felics drill to make a 4-meter hole to anchor the long pole that holds the ARGOS antenna.

Lowering the second thermistor string down the 30-meter hole.

Lowering the second thermistor string down the 30-meter hole.

On that day, the 20-knot katabic winds were blowing a lot of snow, so we used a mountain tent as a snow-proof environment to work with the electronics before dropping off the case in its hole. To give you a taste of the wind speed: Rick was charging one of the thermistor-string battery and the wind was so strong that it blew the small 1kw generator off…. crazy! When the winds finally died down, we buried the case in a 2-meter deep snow pit, because we wanted to prevent the case from being exposed to surface densification and melt during the summer.

Digging a deep snow pit for the thermistor case.

Digging a deep snow pit for the thermistor case.

Last check on the electronics, to make sure all the wires are tightened before closing the box -- next opening in one year!

Last check on the electronics, to make sure all the wires are tightened before closing the box — next opening in one year!

That is it! The box is down the hole.

That is it! The box is down the hole.

After backfilling the snow pit, the only evidence at the surface of the temperature strings is the top of the pole with the ARGOS antenna and a red flag!

After backfilling the snow pit, the only evidence at the surface of the temperature strings is the top of the pole with the ARGOS antenna and a red flag!

We are hoping to recover the case with the datalogger next year, but we are not sure if the ARGOS antenna will still be sticking out, because this sector of the ice sheet is getting a lot of snow accumulation in the winter. We will use a metal detector to find the metal pipes left near the case.

Because this is likely my last post for this expedition’s blog, I would like to thank the all team for this great adventure and everybody that was supporting this exciting research. Until next time!

Notes from the Field