In early April 2015, a small team of 2 Belgian and 2 French researchers went to Svalbard. The goal? Testing new methods to measure sea-ice thickness and ice algal biomass, but also measuring greenhouse gases in the sea ice in relation with the ‘STeP’ (Storfjorden Polynya multidisciplinary study) campaign. With funding from the French Polar Institute (IPEV) and IPSL and logistical arrangements by the Laboratoire d’Océanographie et du Climat (LOCEAN, Paris), we had the opportunity to conduct a short field campaign, long enough to perform instrumental tests and ice coring.
The expedition was arranged with Stefano Poli – a tourist guide in Svalbard. People and equipment were driven on snow-mobiles to Agardhbukta, 100 km South East of Longyearbyen. The conditions for this expedition were quite rudimentary; a tent, a burner and sleeping bags. There are no human settlements in this remote location, so Stefano chose a camping spot, as safe as possible with respect to polar bears, right in front of the fjord, our working place…
Quite exciting, isn’t it? Let’s take a look at what we got up to:
Outside the tent (credit: A. Lourenço).
Setting up the Camp
How do you set up a camp in the Arctic? First, you look for a hidden place, ideal for bear watching (in our case we chose a place with a small hill on our back and open on a wide and flat area). Then the hard work starts:
Build the body and the membrane of the tent.
Dig a hole in the snow right under the entrance to allow carbonic gases to escape.
Set up the oil burner circuit: the oil tank positioned outside the tent is sent to the burner through a pipe covered by snow to avoid spilling accidents, and another pipe made from superposition of aluminum cylindrical cans links the burner to the air above the tent. A hole in the membrane of the tent is designed for that purpose.
Circle the tent with a bear alarm. This was totally handmade and consisted of a gun firecrackers guided by a thread, not really sufficient to stop a polar bear!
The daily life
Eating, sleeping, working, everything was adapted to Arctic conditions. The meals – morning, lunch and dinner – were just dry food in hermetic bags that you fill in with boiling water. Better choose the orange bags, chili con carne is the best. To sleep, reindeer skins were placed directly on the ground (i.e. snow) as mattresses, and sleeping bags were in natural bird feathers. The ideal position is when you find the perfect distance between your feet and the burner.
Inside the tent (credit: M. Kotovitch)
As the bear alarm might not be totally reliable, our guide offered us (well, without the possibility to decline or give up) a memorable nocturnal experiment, a series of 2-h bear-watching shifts, with a survival kit consisting of a flare gun, 2 tea thermos and 1 teddy polar bear for superstition.
In the Field
The objectives of this short campaign were (i) to sample early spring sea ice, snow and seawater in the Storfjorden region; (ii) to calibrate non-destructive methods for ice thickness and biomass retrievals in sea ice; and (iii) to measure greenhouse gases in sea ice in relation with the ‘STeP’ campaign. This cruise is scheduled for next summer in Storfjorden, led by IPSL-Paris and involves paleo-oceanographers, physical and chemical oceanographers as well as biogeochemists from several countries.
Why is it so important to develop a non-destructive method while working on sea ice? Because the general and only way known currently to sample sea ice in its entire thickness consists of coring, which destructs the site and can alter sea ice biogeochemical conditions.
With these goals in mind, the initial plan was to operate 2 or 3 stations per day on coastal landfast ice in Storfjorden. Agardhbukta was chosen for its situation (not too far from Longyearbyen) and as one of the locations in Storfjorden where we had good expectations to find practicable sea ice in this season, which was required to carry out our work. Our guide Stefano mentioned he saw a satellite image with new sea ice on March 23 in that location. And indeed, the sampled ice was probably not older than 2-3 weeks (Figure 4). Regarding the sampling planning, our expectations where a little bit overestimated. The weather conditions were so snowy and windy that we hardly had the time to sample one full station a day… This is how Polar Regions surprise us.
Bear watching (credit: A. Lourenço)
Edited by Sophie Berger and Nanna Karlsson
Marie Kotovitch is a PhD student at the Chemical Oceanography Unit, University of Liège, supervised by Bruno Delille. She is working with sea ice and gas transport (mostly greenhouse gases like CO2 and N2O). She has a collaboration with the Laboratory of Glaciology at the Université Libre de Bruxelles and was involved in this campaign in Svalbard to analyze the biological aspect of this study.
The Norwegian research vessel G.O. Sars after arriving in Tromsø with more than 200 m of sediment cores to document past abrupt climate change. Photo credit: Iben Koldtoft
Going on a cruise for a month sounds tempting for most people and that is exactly how I spent one month of my summer. Instead of sunshine and 25 degrees, the temperature was closer to the freezing point on the thermometer and normal summer weather was replaced by milder weather conditions. The destination of the cruise was the western Nordic Sea and the east Greenland Margin. The ice2ice cruise was not a regular cruise, but a scientific cruise, starting in Reykjavik then heading towards the east coast of Greenland and ending in Tromsø, Northern Norway. Without the option to go ashore and far away from civilization, I spent four weeks aboard the Norwegian RV G.O. Sars. When I came home from the middle of the ocean, I realized that I had been part of a unique project.
The ice2ice cruise logo, where the red dots indicate the more than 30 sites of coring marine sediments under the ice2ice cruise. Photo credit: Amandine Tisserand
Why are climate scientists going on a cruise?
The purpose of the cruise was to collect marine sediment cores in the western Nordic Seas and along the east Greenland Margin. The retrieved sediments can be used to document abrupt changes in sea ice cover and ocean circulation along the East Greenland continental margin, during glacial times and for the more recent past. For this purpose three different sediment coring systems were used. The multicore, which samples sediments, including the sediment/water interface at the sea floor, the gravity core that is used to get information about the deeper marine sediments (up to 5 meter), and the calypso core that could retrieve up to 20 m long sediment cores, containing muddy sediments from the ocean floor to the ship’s deck.
One of the main questions of the ice2ice project is why there are abrupt climate changes. The sediment cores should be ideal for correlation to the RECAP (http://recap.nbi.ku.dk/) ice core from Renland Ice Cap in Eastern Greenland, drilled earlier this year. Together it is a unique material, which hopefully can bring information of the sea ice cover and its extent back in time.
Sediments: a split calypso core showing a clear pattern of a tephra layer from a volcanic eruption (left), and the multicore on the way up with four successful sediment cores (right). Photo credit: Iben Koldtoft and Ida Synnøve Olsen.
When everything is new – also the type of cruise
This was my first cruise ever, and before I boarded the ship in Reykjavik in mid-July, my knowledge of marine sediments and the ocean was very limited. Most of the people on board the ship were geologists who knew a lot about sediments from the ocean and had been on cruises before. Now a month later, my knowledge about sediments and the life aboard a research ship has become much larger. I think I had the steepest possible learning curve about sediments, because there were no stupid questions to ask, and everyone was very nice about answering questions, even if it was outside their area. Usually I work with ice cores and modelling of glacier ice and for me everything was new. This meant that I could contribute with knowledge about the RECAP ice core instead. Now I can take part in a conversation about sediments together with other geologist.
Normally when going on a cruise, there are only a few scientists on board on the ship. This means that there is only time to core the sediments and cut them into sections, while all the scientific work takes places later, when the sediments are in the lab. On this cruise, as something new, we were several scientists, so when the sediments were on deck, we immediately did a splendid job of handling the cores, describing and analysing the material. Thus, the detailed lab analyses can start right away after the material gets back to Bergen.
Shipboard analyses indicated that the material we have brought back to the laboratories in Bergen covers a time span from the present and probably a few hundred thousand years back in time. Not all the data have been analysed yet but we are looking forward to start and we are eager to see the results.
Midnight sun over the Greenland Sea. Photo credit: Dag Inge Blindheim.
During the one month long cruise, we had collected numerous samples of shells from the ocean floor from 32 stations west of Iceland. We did CTD (Conductivity, Temperature and Depth) measurements, to get information about how the temperature, salinity, density and oxygen content of the water vary in the ocean, and we collected water samples at different depths to analyse oxygen and carbon isotopes. We also collected sediments from 31 stations and every core has passed the DNA sampling, color and MS measurements stations. The cores were then cut into sections, split down through the middle, logged and described so that we could get an initial feel for the quality and utility of the samples we retrieved, before they are brought to shore for much more detailed analysis.
Ashley, Margit and Ida cut a gravity core into sections (left), while Alby brings a multicore from the deck down to the lab (right). Photo credit: Dag Inge Blindheim and Kerstin Perner.
Working 24-hour shifts on the ship meant that we achieved a lot and we brought home more than 200 m of muddy sediment cores from the sea floor from the western Nordic Seas and the east Greenland Margin and more than 190 water samples.
Although it was 12 hours of hard work most of the days, it was a pleasure to be part of the cruise. It has certainly not been my last cruise, if it is up to me, and I will look forward to a new cruise if I am lucky enough to get the chance. Weather was nice most of the time, but of course, we had some days of rough seas. The professionalism of the crew of G.O. Sars created an excellent atmosphere for work and time off, it was more like being on a real 4 star cruise if we ignore the time we worked.
Henrik is taking DNA samples of a gravity core (left) and water samples from the CTD (middle). Photo credit: Iben Koldtoft. I am happy after having packed one of the last sediment sections, which is now ready to be sent to Bergen and further analyzed (right). Photo credit: Kerstin Perner
On the ice2ice cruise the scientists were Eystein, Carin, Jørund, Dag Inge, Bjørg, Christian, Margit, and Amandine from Uni Research (Uni Research Climate, Norway), Stig, Sarah, Evangeline, Henrik, Ashley, and Ida from UiB (University of Bergen, Norway), Flor from GEUS (Geological Survey of Denmark and Greenland, Denmark), Mads from CIC (Centre for Ice and Climate, Denmark), Kerstin from IOW (Leibniz Institute for Baltic Sea Research Warnemünde, Germany), Albertine from Bris. (University of Bristol, UK), and myself Iben from DMI & CIC (Danish Meteorological Institute & Centre for Ice and Climate, Denmark). We were 19 participants, 8 men and 11 women, representing 8 different nationalities, and supported by a ship crew of 15. We were in good spirits all the time and a successful cruise!
The scientific crew of the ice2ice cruise. Photo credit: Iben Koldtoft
The cruise would not be possible without support from the European Research Council Synergy project ice2ice (Danish-Norwegian), Bjerknes Centre for Climate Research (Norway) and Institute of Marine Research (Norway), who provided research vessel and crew onboard.
Iben Koldtoft is PhD student within the ice2ice project at Danish Meteorological Institute and Centre for Ice and Climate, University of Copenhagen, Denmark and supervised by Jens H. Christensen and Christine S. Hvidberg. She is interested in modelling the dynamics of the Greenland Ice Sheet and the smaller glacier, Renland Ice Cap, in the Scoresbysund Fjord, Eastern Greenland. Currently she is coupling the ice sheet model PISM to the ocean by implementation of calving to the model. Surface mass balance simulations of the Greenland Ice Sheet will later be used to assess the quality of the interaction between the ice sheet model and a climate model in comparison to observations.
The Case tractor pulling the dome. Credit: N. B. Karlsson.
Moving 150 tonnes of equipment more than 450km across the Greenland Ice Sheet sounds like a crazy idea. In that context, moving a 14-metre high, dome-shaped, wooden structure seems like a minor point, but it really is not. I do not think I realised what an awesome and awe-inspiring project I was part of, until I was out there, in the middle of the blindingly white ice sheet, and I saw the enormous, black structure moving slowly towards our first stop for the night.
Traverse route from NEEM to EGRIP. Topographic map from Bamber et al., 2001, JGR.
Why are we doing this?
Our field camp NEEM has been inactive since 2012, when the last samples were retrieved from the 2.5km deep borehole. In the following 3 years, scientists and traverse teams have visited the deserted camp occasionally. Now it was time to move everything and start all over on a new drilling project, EGRIP (East Greenland Ice core Project) in Northeast Greenland.
Helle, Paul and Anna readying one of the sledges for the traverse. Credit: N. B. Karlsson.
How do you move an entire camp?
In 2012, most of the equipment was packed down on big sledges ready to move, and the dome was fitted with four big skis. The first task this year was to check that everything was in order for the traverse. Let me start by saying that one cannot overestimate exactly how much snow can pile up during three years. The key piece of equipment is therefore a shovel. To be precise, you need a whole bunch of shovels. The two garage tents also had to be taken down. It turned out that they were encased in ice, so add some spades and a couple of sledgehammers to the required equipment.
Freeing the dome
Finally, the skis under the dome had to be freed. The shape of the dome means that the snow drifts around it instead piling up, but the skies under the dome were covered in a mixture of ice and snow. When I look at the photos now, it seems almost unbelievable that we manually cut free and moved away that amount of ice. The piles of ice blocks grew and grew during the two days, where people were working away with chainsaws, shovels and hands to clear the skis. In the meantime, Sverrir, our Icelandic mechanic, displaced tonnes of snow in front of the dome, in order to build a ramp for dragging up the dome.
Freeing the dome using shovels, chainsaws and a pisten-bully. The skies are beginning to emerge from under the dome. The skis support the “bike wheel” (blue) that the dome is mounted on. Credit: N. B. Karlsson.
“It’s going to topple”
I do not think I will ever forget the nerve-wracking moment when the dome was first jolted free. As it moved slightly forward one of the skis lifted completely off the ground, and for a brief, alarming second I thought, “It is going to topple”. Then with a thud, the ski reconnected with the ground and the dome moved slowly up the ramp towards its first stop on the way to EGRIP.
Once the traverse started, the days passed in a blur. You get up early, and some days you wait for hours before setting out because there is a problem with one of the vehicles. Other days, everything works perfectly and you scramble to get everything you need out of the dome, before the ladder is hoisted up and the traverse is on its way. Our convoy was a very mixed lot of vehicles; the big Case tractor driven by Pat pulled the dome. Two Pisten-Bullies pulled sledges containing everything from fuel and extra living quarters to our old forklift. Then we had two Flexmobiles, the elderly gentlemen of the convoy, going at a nice, sedate speed, and finally three skidoos, the science teams.
Anna is checking the radar equipment while one of the pisten-bullies is approaching. Credit: N. B. Karlsson.
The freedom of skidooing
Driving a skidoo, we had a lot more freedom than the heavy vehicles. It is easier to make a quick stop on a skidoo and it is often necessary, if there are problems with the equipment. The downside is that it is significantly colder to spend all day on a skidoo than inside a nice, warm cabin. Temperatures were often below -20 degrees Celsius, and although we were fortunate and did not have high winds, it still gets chilly at the end of the day. The solution is to dress warm, in a ridiculous number of layers, and to eat a lot. After a few days we were experts in identifying food that do not freeze easily (salami, fat cheese, brownies), or food that does freeze but is still tasty frozen (smoked halibut, ham).
At the end of the traverse, Helle, Paul and Sepp had collected numerous samples of the surface snow, dug several metre-deep snow pits and drilled three shallow cores, one of them 15m deep. Simultaneously, Anna and I collected radar data along (almost) the entire traverse route. The data have not been analysed yet but we are looking forward to see the exciting results of our combined efforts.
Helle and Paul are drilling a shallow core while Anna is waiting for the traverse train to pass. Credit: N. B. Karlsson.
Although our traverse is over, the EGRIP project is just beginning. The aim of the project is to investigate the dynamics of fast-flowing ice streams by drilling an ice core through the Northeast Greenland Ice Stream. The EGRIP camp will run until 2020 and next year the camp infrastructure will be set up and drilling will start. Exciting times ahead!
On the traverse we were Dorthe, Helle, Joel, Jørgen Peder, Paul, and myself from CIC (Centre for Ice and Climate, University of Copenhagen, Denmark), Anna and Sepp from AWI (Alfred Wegener Institute, Bremerhaven, Germany), Sverrir, our Icelandic mechanic, Matthias the medic, and Pat Smith from the Greenland Inland Traverse, GrIT, a logistics operations funded by the US National Science Foundation. We were 11 participants, 7 men and 4 women, representing 5 different nationalities, and we had an amazing time!
The project would not be possible without support from the A.P. Møller Foundation, University of Copenhagen, the Alfred Wegener Institute (Germany), Bjerkness Centre (Norway) and the National Science Foundation (USA), who provided staff and a tracked vehicle.
A typical iSTAR field camp with the living ‘caboose’ on the left (credit: Damon Davies).
It’s the 2nd December 2013 and I find myself in one of those rare occasions in life where I feel I need to pinch myself to see if I’m dreaming. Why? Somehow I’m in control of a British Antarctic Survey De Havilland Twin Otter aircraft flying over the white featureless expanse of the West Antarctic Ice Sheet. I’m part of a team of 12 heading to Pine Island Glacier, a remote ice stream 75°S and around 1500 km from Rothera Research Station on the Antarctic Peninsula.
The journey so far has taken four flights from London to Punta Arenas on the Southern tip of Chile and across the Drake Passage to Earth’s southernmost continent. Our pilot, John is having some lunch and keeping a close eye on my erratic attempts to hold a constant bearing and altitude as I ‘co-pilot’ the final leg of our journey. On the horizon I spot a thin strip of bright white snow that marks the groomed ski-way of our landing site.
John takes back the controls and eases the throttle down for a perfectly smooth landing. I step down from the plane with a familiar squeak and crunch of cold dry snow underfoot in an unfamiliar environment like nothing I’ve experienced before. I squint as my eyes adjust to the bright white desert of flat ice sharply contrasted by a crystal clear blue sky spanning the distant horizon in every direction. This will be my home for the next few months as I embark on my first Antarctic field season as part of the first iSTAR science traverse of Pine Island Glacier.
The iSTAR research programme
iSTAR (ice sheet stability and research programme) is a £7.4 million research programme funded by the UK Natural Environment Research Council (NERC) involving 11 UK universities and the British Antarctic Survey (BAS). Its aim is to improve understanding of ice-ocean interaction and ice dynamic response of Amundsen Sea sector of the West Antarctic.
Over the past few decades this region has been undergoing the greatest rates of ice loss on the planet causing concern over its potential future contribution to rising global sea-level. Pine Island Glacier (PIG) drains around 10% of the West Antarctic Ice sheet (WAIS) which contains enough ice if melted to raise global sea-level by approximately 3.3 metres.
In order to make accurate predictions about how this region will respond to environmental change requires good physical observations and measurements. Throughscientific ocean cruisesand an over-ice traverse spanning two field seasons combined with satellite remote sensing and numerical modelling, iSTAR aims to provide the data necessary to improve the accuracy of projections for the contribution of the WAIS to future sea level.
The iSTAR traverse of Pine Island Glacier
Traditionally the UK has conducted glaciological investigations in remote regions of Antarctica using small field units typically consisting of one scientist and a field assistant. For larger drilling projects equipment has to be flown by aircraft at great expense and fuel consumption.
For iSTAR, a new approach was undertaken using two ‘tractor trains’. These consist of two Pisten Bully snow tractors towing two long poly sleds with fuel bladders and three metal cargo sledges including a living ‘caboose’; a converted shipping container with a cooking and living space (essentially a caravan fit for polar travel!). All this equipment was delivered by the RRS Ernest Shackleton to the Abbot Ice Shelf in February 2012 and driven to Pine Island Glacier ready for the first traverse the following season.
iSTAR tractor train (credit: Alex Taylor).
This infrastructure provided a means to meet the ambitious science aims of the iSTAR traverse making it possible to collect more ground measurements over a wider area than ever previously possible and with greater fuel efficiency.
The traverse follows a 900 km route visiting the trunks and tributaries of PIG to conduct a range of measurements on the ice.
The route of the iSTAR traverse of Pine Island Glacier, West Antarctica (credit: www.istar.ac.uk).
So what about the science?
The iSTAR programme is split into four science projects, with iSTAR A and B making measurements from scientific ships and iSTAR C and D collecting data during the overland traverse of Pine Island Glacier. It is the overland traverse that we were involved in.
iSTAR C: Dynamic Ice project:
This project aims to understand the internal dynamic processes responsible for transmitting the effect of thinning of PIG’s floating ice shelf caused by melting of warm ocean currents upstream into the trunk and tributaries of the ice stream. Of particular interest is how the underlying geology of the ice influences its flow.
Over the course of two field seasons the traverse collected over 2000 km of radar data and over 40 km of seismic surveys were completed. The team used skidoos to tow radar equipment across the ice making the most of the 24 hours of daylight of the Antarctic Summer to provide detailed images of the ice thickness and bed topography. The geology of the subsurface was also investigated by analysing the seismic energy returned from small explosive charges buried in the surface of the ice.
Operating the ice penetrating radar (left) and firing explosives for seismic surveys (right) (credit: Damon Davies).
iSTAR D: Ice Loss project
Satellite measurements over the past two decades have revealed rapid thinning (up to 1.5 metres per year) and acceleration of PIG’s ice flow. The iSTAR D project aims to take measurements to extend the record of past snow accumulation and ice density to improve estimates of ice loss that cannot be determined from satellite measurements.
To determine past accumulation and understand surface processes such as snow density changes and compaction, we drilled 10 shallow (50 metre) ice cores. These ice cores had to be kept frozen and shipped back to the UK where their chemistry is being analysed to enable us to quantify how much snow has fallen onto the ice sheet in the past. Over 20 snow density profiles were recorded using a device called a ‘Neutron Probe’ which uses a radioactive source to measure neutron scattering from within the snowpack to calculate ice density. This might sound dangerous but to my disappointment after spending many hours operating this equipment I have yet to develop super powers!
Rob, Becky and Emma inside the ice core drilling tent (left), Damon and Andy working at a Neutron Probe site (right) (credit: Alex Taylor).
Surface radars operating at the same frequency as satellites that orbit the earth measuring ice surface changes were also deployed. These ground radar measurements enable us to improve the accuracy of satellite derived estimations of ice volume loss from West Antarctica.
Anna operating the surface radar (credit: Jan De Rydt).
Now you know all about iSTAR science but what’s it like to live and work in one of the most remote regions of the coldest, highest, driest and windiest continent on Earth?
Life in the field
Life on the iSTAR traverse is perhaps similar to a travelling circus, only instead of jugglers and gymnasts we have scientists and mechanics and rather than a ‘Big Top’ we had the ice core drilling tent. At each of the 22 sites on the traverse route the circus would set up camp for a few days to a week. Tents would be pitched, sledges un-hitched and science equipment unloaded, the whole process of setting up camp taking just an hour or two.
Setting up the drilling tent (left). iSTAR accommodation (right) (credit: Alex Taylor).
This region of Antarctica has a reputation for wild weather. Temperatures can drop below -30°C and winds can reach hurricane speeds reducing visibility to within a few metres. However, on calm days it can be so silent you can hear your own heartbeat and the strength of the summer sun provides welcome warmth. Good weather means working long hours as you never know how long it might last. When the weather takes a turn for the worse, all you can do is shelter from the elements and wait patiently for the storm to pass, though patience can be tested when the storm lasts for a week!
iSTAR team members battling a storm (left) (credit: Alex Taylor). Tent damage after a big storm (right) (credit: Damon Davies).
The living ‘caboose’ offers a warm shelter away from the elements. This is also where the team gathers at meal times with everyone taking turns to cook for the rest of the group. The iSTAR menu normally consists of a porridge breakfast, soup and bread for lunch, some form of carbohydrate with meat slop for dinner followed by tinned fruit/pudding with powdered custard for dessert. The labels of some meal packages such as ‘chicken own juice’ and ‘sausages in lard’ aren’t particularly enticing but generally the food is good by Antarctic field standards.
Dinner-time in the caboose (left) (credit: Alex Taylor). James finishing off a cottage pie with a blow torch (right) (credit: Damon Davies).
The iSTAR traverse was an incredible experience that allowed me to learn a range of data acquisition techniques as well as learning how to work in the often hostile Antarctic weather. I was one of 9 PhD students and post-doctoral researchers involved in the traverse seasons who were able to work alongside highly experienced scientists in the field. Our success is a testament to the hard work and good spirit of everyone involved.
Left photo, 2013/14 traverse participants. Left to right, Anna Hogg (Leeds), Rob Bingham (Edinburgh), Andy Smith (BAS), Damon Davies (Edinburgh), Johnny Yates (back row, BAS), Tim Gee (middle, BAS), Jan De Rydt (front, BAS), Steph Cornford (Bristol), James Wake (BAS), Peter Lambert (Reading), Thomas Flament (front, Leeds), David Vaughan (BAS) (credit: David Vaughan). Right photo, 2014/15 traverse participants. Left to Right, James Wake (BAS), Mark Baird (BAS), Tim Gee (BAS), Emma Smith (BAS), Isabelle Nias (Bristol), Robert Mulvaney (BAS), Andy Smith (BAS), Alex Brisbourne (back row, BAS), Rebecca Tuckwell (middle, BAS), Alex Taylor (front, BAS), Sebastian Rosier (BAS), Damon Davies (Edinburgh) (credit: Alex Taylor).
For more information about the iSTAR research programme visit www.istar.ac.uk and the ‘stories from the field’ blog posts to read more tales from traverse fieldwork.
Acknowledgments: A huge thanks to James Wake, Tim Gee, Johnny Yates, Mark Baird and Alex Taylor for their tireless support in the field. The traverse could not have succeeded without support from the staff at Rothera Research Station. Also thanks to Emma Smith for helpful comments on this blog.
Edited by Sophie Berger
Damon Davies is a PhD researcher at the University of Edinburgh, School of Geosciences Glaciology and Cryosphere research group. His research uses geophysics to investigate the dynamics of ice stream beds and their control on ice stream flow.
19 November 2014, the Iliuchine 76 gently lands on the runway of the Russian Antarctic station, Novolazarevskaya, in Dronning Maud Land. For the first time, I’m in Antarctica! It is 4 o’clock in the morning and we need to hurriedly offload 2 tons of material intended for our field mission near the Belgian Princess Elisabeth Station. I’m deeply impressed by the landscape although it is dotted with containers, people and machines. I am impressed by the fuzz. I am impressed by the novelty. I am impressed by the icescape. It is cold, but I don’t feel it.
(Credit B. Van Liefferinge)
I take part in an expedition lasting five weeks and led by the Laboratoire de Glaciologie of the Université Libre de Bruxelles (ULB) in the framework of the Icecon project.The project aims at constraining past and current mass changes of the Antarctic ice sheet in the coastal area of Dronning Maud Land (East Antarctica) to better understand past and present ice volumes and the extension of the Antarctic ice sheet across the continental shelf during the last glacial period. This year we are a team of 5 to do the job: GPS measurements, ice-core drilling, high- and low-frequency radar measurements (GSSI and ApRES), televiewer measurements … The ApRES radar is a new phase-sensitive radar developed by British Antarctic Survey (BAS), capable of detecting internal structures in the ice and changes in the position of internal layering over time.
After a couple of hours at the Russian base, it’s time to fly to the Princess Elisabeth Station (the Belgium base, PEA). The arrival in a Bassler (a former DC3 re-equipped with turbo-props) with stunning views of the Sor Rondane Mountains and the Princess Elisabeth station on the Utsteinen rim is simply magnificent. Alain Hubert, the base manager, gives us the first security rules and shows us the different parts of the base.
(Credit B. Van Liefferinge)
After following the various field training and especially an exercise that aims at pulling yourself out of crevasses, it’s time to inspect, to set up, and to test our equipment. While one part of the team sets up the drill, Frank Pattyn and I test the GPS and radar equipment, mainly the ApRES that is a new “toy” for us. The first results are promising, we can clearly identify the bed topography and internal layers. The two GPS systems sponsored by the “10km of the ULB”, a run organised by the students of our Faculty, are also tested next to the L1L2 GPS systems for precise positioning. As our departure is imminent, I’m excited (even though my level of Coca-cola are getting low – I ‘m an avid consumer of this “evil drink” and Frank was afraid that I wouldn’t survive without sufficient sugar intake).
(Credit B. Van Liefferinge)
On 27 November, we leave PEA in the evening for one night and one day across the Roi Baudouin Ice Shelf to Derwael ice rise. We are 6 scientists, 2 field guides and 1 technician. After 25 hours of travel, we set up the camp on the top of the divide. We start immediately with the radar measurements to locate potential drill sites. However, we get caught in a storm the following day and as Frank says “not a nice one”.
(Credit F. Pattyn and B. Van Liefferinge)
The snow drift is just amazing and the atmospheric pressure drops frighteningly (“can this still go lower?”). The whiteboard installed in the living container is not wide enough to draw the graph of pressure change, nor is it high enough to accommodate the lowest values. Furthermore, it’s quite warm, meaning that snow melts in contact with persons and goods. Despite efforts of everyone to clear away the snow, we leave our tents and sleep in the containers for 2 days. Not the most comfortable nights, because we share a two-bunk space with three people, and despite a container it remains very shaky! After three days of amazing experience, we clean up the camp and the science restarts. For one week Frank and I perform radar and GPS measurements in a 10km radius around the camp. These measurements will be repeated in 2015-2016 to provide new data on ice compaction, density and flow. While Frank thoroughly checks the collected data, I have some time to get familiar with the drill, which should prove to be very useful thereafter. The “drill part” led by Jean-Louis Tison and Morgane Philippe aims at drilling two 30 m deep ice cores on Derwael Ice Rise, 2 km on each side of the divide. We want to investigate the spatial variability of snow accumulation induced by this ice rise that sticks approximately 300 m above the surrounding flat ice shelf and therefore perturbs the surface mass balance distribution (Lenaerts et al., 2014).
(Credit F. Pattyn and B. Van Liefferinge)
I use this week to improve my knowledge on other scientific techniques, such as the coffee-can method (will complement the results from the ApRES) or geodetic GPS measurements with Nicolas Bergeot. I also learn the basics of snowmobile mechanics (it’s surprising to see the amount of snow that can be put in an engine!). Unfortunately we get stuck for another 2 days by a new storm event. We use this time to have a look on the first radar profiles and to prepare the second part of the expedition.
On 9 December, we leave the camp on Derwael ice rise and move towards the Roi Baudouin Ice Shelf, 40km to the west. We set up the camp in a longitudinal depression (like a trench) on the ice shelf that stretches from the grounding line to the coast.
The purpose of this part of the field work is twofold: first of all, determine the mass budget of ice shelves. To do that, we need to map carefully the flow speed of the ice-shelf. Secondly, understand the formation of the trench in evaluating if under the ice-shelf, the ice is melting or accreting (formation of marine ice) and analyze the surface melt history by investigating near-surface melt layers.
The first three days are devoted to make radar measurements (ApRES) in the center and on the sides of the trench. The thickness of ice and the reflection at the interface with the ocean is different from the one on the ice rise; we take some time to develop a robust method and determine the best settings of the radar. Together with Frank Pattyn and Jan Lenaerts (InBev Baillet Latour fellowship, http://benemelt.blogspot.be/) I perform a 120km transect with a high-frequency radar towed by a snowmobile to map the near-surface internal structure along the ice shelf and link the drill site with the grounding zone. Driving at 8 km per hour for 8 hours a day, it’s an opportunity for me to think about how lucky I am to be here. Alone in the vastness of the Roi Baudouin ice-shelf, I feel very small. Back in camp, we find out that the drill got stuck at a depth of 54m in the borehole and preparations to free the drill are on their way. During this time I carry out a number of high-frequency radar measurements with Alain Hubert (the base manager) to fine-tune the equipment to potentially detect crevasses near the surface. To our surprise, we stumble upon a crevasse more than 500m long, 10m wide and 20m high. Moreover, we can safely descend through the apex of the crevasse to discover its vastness. Truly a magic moment!
(Credit A. Hubert)
Thirty-six hours later, and thanks to antifreeze, the drill restarts. This small technical incident pushes us to work the next couple of days through the day and the night (under the sun at 3am is rather special) and we take turns in operating the drill. We reach a depth of 107m, not far from the 155 meters needed to reach the bottom of the ice shelf, but the brittle ice makes progress very difficult. Nevertheless, this is the third core of the (short) season, and as valuable as the previous ones. We can clearly identify every single ice layer over 200 years as well as the surface melting history.
(Credit A. Hubert)
Before leaving back to the base, we finish the installation of the famous Tweetin’IceShelf project (http://tweetiniceshelf.blogspot.com); a project also presented at the EGU General Assembly in 2015. We deploy two GPSes on the flanks of the trench and one in the center. These are simple GPS systems that record their position every hour. They are named GPS CGEO (from Cercle de Géographie et de Géologie de l’ULB) and GPS CdS (from Cercle des Sciences). In the center of the trench, the ApRES is installed which measures once a day the radar signal through the ice. All systems will be effective throughout the Antarctic winter. Data are sent via Twitter to be followed by a larger community. Just follow the @TweetinIceShelf on Twitter. You will not be disappointed.
(Credit F. Pattyn)
It’s time to go back to the station, which is reached after 20 hours of travel across the ice shelf and the coastal ice sheet. Over 2 days we will be at Cape Town and we have to clean up everything for the next field season.
(Credit N. Bergeot)
I know it is my first time to Antarctica, and as most first-timers, an unforgettable experience of vastness, whiteness, silence, laughter, hard work and fun. When I board the plane I feel delighted and fulfilled and ready to find back green landscapes and city soundscapes in less than ten hours.
Brice Van Liefferinge is a PhD student and a teaching assistant at the Laboratoire de Glaciology, Universite Libre de Bruxelles, Belgium. His research focuses on the basal conditions of the ice sheets.
Last summer we got the chance to participate in an incredible Arctic expedition. The mission was clear and yet unclear at the same time: Bring your fanciest laser technology on a wooden schooner. Then cross the Atlantic and sail to the fjords of southern Green
land and conduct science throughout the journey. During most of our expedition, our “scientific lab” contained icebergs, glaciers and beautiful fjords or open waters; And we even got the chance to experience northern lights and a visit from a polar bear. But unavoidably also the not so pleasant feeling of seasickness….
Sailing into one of many fjords on the south-east coast of Greenland. (Credit A.-K. Faber)
On June 24rd 2014 a majestic wooden schooner, set sail and began a fantastic journey across the North Atlantic Ocean. The journey was split up into three legs: 1) from Copenhagen (Denmark) to Reykjavik (Iceland), 2) from Reykjavik to Narsarsuaq (Southern Greenland), 3) from Narsarsuaq to Copenhagen. The first and the third leg of the journey was primarily “transporting” the ship to the remote environment where most of the scientific research projects was scheduled. On two of these legs, we were the only scientists onboard experiencing the amazing feeling of being on an old wooden schooner crossing the North Atlantic Ocean. The second leg of the journey was the part with the most scientific enrolment. On this leg, scientists with different backgrounds and interests were onboard conducting experiments primarily in the remote fjords in the south-eastern part of Greenland.
Some people might recognize the ship as the ship used in the documentary “Expedition to the end of the world” where scientists and artists went on a polar expedition together. No artist participated this time and the aim of this expedition was purely scientific. The purpose was twofold; to conduct science in the Greenlandic fjords, second to gain experience before the realization of a future circumpolar scientific expedition.
The route of the trip, plotted using linear interpolation of the measured GPS positions. (Credit M. Winther)
The vessel was working as a floating field station and we were part of a larger team of scientists from different fields all taking advantage of this unique opportunity. Using the ship as a base for research had some logistical advantages, as it was easy to move from one location to another and research could be done onboard the ship or on land. On a typical day, some scientists would stay on the ship and others would jump into small zodiacs or use special airborne transportation. Then they would transport themselves to nearby field sites to collect data.
The expedition ended with a beautiful and fairytale-like morning on the 20th of September 2014. Sailing on a calm sea during an early summer dusk, with the first sunshine of the day in our backs, passing the old Kronborg castle (the Northern tip of Sealand, Denmark) and sailing with the sails the last miles back to the harbor across from the Queens palace in the center of Copenhagen.
Left: The view of Kronborg as seen from the Captains view. (Credit M. Winther). Right: Sun rise as sailing in the North-sea. (Credit M. Winther)
History of Activ
The research vessel used for this incredible expedition was the old ice-class cargo vessel named “Activ”. Activ was built in 1951, and was in the first 27 years used as a cargo vessel for the Royal Greenland Trading Company sailing on the eastern coast of Greenland. In 1978, the ship was re-rigged as a topgallant schooner with room for 16 persons including a Captain and crew members. Even after this update Activ remained as an “old fashioned” sail and motor-driven vessel, which means that it is preferable to sail only with sails, which need to be handled with pure manpower. With a total of 13 sails, everyone onboard was obligated to help when needed.
The majestic arctic schooner “Activ” (Credit: A.-K. Faber)
But now, let’s talk science. During this arctic shipboard expedition we brought a water vapor Cavity Ring down Spectroscopy (CRDS) isotope analyzer namely the Picarro G2301 analyzer. Using this analyzer we endeavored to perform online continuous measurements of the water vapor isotopes in the lower 25 meter of the marine boundary layer over the entire expedition. In order to measure the water vapor continuously, we made an onboard dual-inlet setup. For the majority of the expedition we measured from an inlet placed at the top (at approximately 25 meters) of the mizzen mast (stern mast). From this inlet the water vapor was drawn down to the instrument using a pump standing next to the Picarro analyzer. To prevent condensation of water vapor between the inlet and the analyzer, the water vapor was transported through an insulated heated (30°C) cobber stainless steel tube. The second inlet was at the end of an “arm” attached to the site of the vessel. This arm had the same kind of insulated heated cobber stainless steel tube for transporting the vapor in. The special thing about the arm is that it gives us the means to draw vapor from different elevations quickly and very easily and quickly.
Using this dual-inlet system we measured almost continuously, from 25meters above sea-level, for the full expedition time over both the ocean and in the fjords. When in the fjords and when we experienced calm weather, we used the “arm” to draw vapor from different heights above the water.
Left: The mizzen mast with the top inlet just above the navigation systems. Center: The “arm” with the second inlet attached. Right: Installation/reparation of the top inlet required harness ect. (Credit A.-K. Faber and M. Winther)
The purpose of our part of the expedition was to gain more knowledge about the physical processes affecting the water vapor in the atmosphere. This is important because we can use this knowledge to improve the general interpretation of the climate system, the representation of water vapor in climate models, and interpretation of observations on water isotopes in the Greenland ice cores.
The development of laser-based isotope analyzers are relatively new. Therefore only a very limited amount of vapor measurements exist for the Arctic region. Understandably we found that the unique route of the expedition yielded excellent conditions for monitoring the water isotopes in the vapor throughout the duration of the expedition.
Being on an expedition like this gave us a lot of unforgettable moments, of which only a few is written here.
The analyzer and the setup placed in the cabin where we slept. (Credit M. Winther)
The instrument we used for this expedition (the Picarro G2301 analyzer) was, together with the rest of the measuring and calibration setup, placed in the same cabin as we were sleeping. This was because of the limited space and the need for a stable “lab”. The cabins onboard were all with 2-3 beds and closets/chests for clothing etc. and therefore relatively large compared to our expectations. Though having a continuously running Picarro analyzer and setup in the closet, the cabin quickly became unwanted by anyone but us (since we had to stay there because of the limited beds onboard). Having the analyzer in the cabin, resulted in both some positive and negative consequences. For example, we never felt cold while sleeping in the cabin and there were more onboard privacy for us (sleeping in the lab-cabin). The downside was that we had to sleep with earplugs, since a constant noise at approximately 90 decibel from the instrument is not pleasant, and we had no closet for our clothes. But despite this we enjoyed being onboard, and we have had a lot of fun of our new meaning of “sleeping with Picarro”.
A wild polar bear as seen from Activ. (Credit A.-K. Faber)
Being on a shipboard expedition in the south-eastern part of Greenland, comes with some expectations for spectacular adventures. On this expedition we were not disappointed, since we had a close encounter with a polar bear and multiple nights with the magic of Northern lights. The polar bear encounter was luckily not a threat, it just wanted some chocolate from the zodiac which was on the side of the vessel in the water. The bear was curious but nothing dangerous ever happened.
We both think that we have had an amazing expedition which have given us memories for life. Life as a young scientist in the arctic is not bad at all!!
Left: Iceberg watch from the side of the vessel when entering the fjords. Right: The vessel as seen from the top of the fore mast. (Credit A.-K. Faber)
Anne-Katrine Faber and Malte Winther are Ph.D. students at Centre for Ice and Climate, The Niels Bohr Institute, University of Copenhagen, Denmark. They are working with water isotopes and continuous measurements of N2O isotopomers, respectively.
A curious polar bear investigates an instrument tower on sea-ice. Photo: Jakob Sievers.
A story about CO2 -fluxes between sea-ice and the atmosphere
What’s it all about?
Whenever I have had to describe my PhD research project to people outside of my research community, I have always found it useful to use an analogy most people are familiar with, namely beers. Now that I have the full attention of the entire class, allow me to explain. Say you were to find yourself at an outside café, grabbing a beer in the beautiful weather with your friends. You get caught up in the conversation and soon your beer is lukewarm and stale and you struggle with the last few drops while gesturing somewhat frantically at the waitress to bring you a new beer. What has happened? Well, the partial pressure of CO2 (pCO2) in the beer is much larger, relative to that of the atmosphere. This leads to gradual diffusion (or flux) of CO2 from the surface of the beer into the atmosphere, and eventually the establishment of an equilibrium pCO2 in the beer, similar to that of the atmosphere. Of course, you have probably been waving at the waitress long before the equilibrium is reached. Now imagine that you had performed this experiment in the cold of winter. The waitress brings you a beer and from the moment it reaches your table a thin layer of ice starts forming on the top. What happens with the CO2 levels now?
Though a bar would probably have been a nice place for fieldwork, obviously my fieldwork took place in a much colder environment, namely the arctic sea-ice in northeast Greenland. The kingdom of the sort of curious four-legged fella shown in the photo above. And the answer to the above question might be “nothing” in the case of a beer. I.e., the ice works as a sort of lid on the beer, preventing any fluxes of CO2 from occurring, but what about in a sea-ice environment? Until very recently the beer analogy would have applied equally well here, as most scientists would have told you that no CO2 fluxes could take place in this sort of environment. Accordingly, all climate models currently treat sea-ice covered regions as regions of no exchange in terms of CO2. Lately, however, a number of papers have been published, suggesting that fluxes can occur at different stages of the annual sea-ice cycle. The paradigm shift occurred when it was discovered that CO2 may be transported through brine channels within the sea-ice. Brine channels form within sea-ice because of the salt in the sea-water, and they tend to be larger if the temperature is higher. So, at the bottom of the ice where the ambient temperature is a balmy 0°C, the channels are largest (Fig. 1).
It is thought that the bulk of fluxes occur primarily in the spring during sea-ice melting. To understand why, we have to go back to when the sea-ice is formed during wintertime. As the ice forms, salts and CO2 are concentrated in the brine channels, and are expelled into the ocean through the larger brine channels in the bottom of the ice. The process is called gravity drainage and refers to the sinking of the highly saline and cold brine water which is denser relative to the underlying sea-water. Some of the expelled CO2 will continue to the deeper ocean column and as such lead to a CO2 loss of the original surface system. Hence, upon springtime melting, the upper water column has less CO2 than the atmosphere, which then causes an uptake of CO2 from the atmosphere. I.e.: a re-carbonization of the beer, so to speak. The mechanism has been coined the sea-ice driven carbon pump and has been estimated to drive an annual uptake of 50 million tons of carbon annually in the arctic alone, constituting a significant fraction of the total CO2 uptake of the arctic ocean which is estimated to be 66-199 million tons of carbon annually. Hence, understanding the impact of this carbon pump is important, particularly because the impact of climate change is felt more dramatically in the arctic compared to the rest of the world. Sea-ice cover is becoming increasingly ephemeral and glacial freshwater runoff, which inherently has a low partial pressure of CO2, is becoming increasingly ubiquitous in the fjord systems.
What are the challenges in this field of study?
To incorporate the carbon pump into existing climate models we need first to understand the physical and biogeochemical processes which drive sea-ice carbon fluxes in both coastal and open water conditions as well as during the entire life-cycle of sea-ice. Sounds simple, right? Of course not. Like most experimental investigators in cryospheric sciences we are struggling with considerable logistical challenges in a vast and unforgiving environment, where temperature conditions often have instrument-developers shaking their head in disbelief. “We didn’t test the instrument for that sort of thing”. How reassuring. Secondly, there are substantial risks involved, both for people and instruments, when conducting experiments during periods of thin sea-ice, which also happen to be the periods in which fluxes are most pronounced, and thus all the more important to understand. Fortunately we are equipped with fairly unique vehicles for transportation during these conditions (Fig. 2). Finally, the fluxes that are reported on sea-ice are often significantly smaller than what is typically reported in terrestrial environments, leaving investigators at times struggling to discern actual measurements from artificial noise.
Figure 2: Our polar air-boat for safe and fast transportation on thin sea-ice. During the experiment this bad boy was typically referred to as a gasoline-to-noise converter. In this particular picture the air-boat is pictured on thick sea-ice, hence the use of normal winter clothing instead of marine safety suits. Photo: Jakob Sievers.
What did I focus on during my PhD?
A common method for flux-observation is the micrometeorological Eddy Covariance method. It involves setting up a 2-5m high tower on a surface of interest and at the top installing:
(1) A three-dimensional ultrasonic anemometer, which measures 3D wind patterns,
(2) A gas analyzer, which measures the atmospheric concentration of e.g. H2O, CO2 or CH4 depending on which type of flux you are interested in.
Figure 3: Our eddy covariance tower on thin ice (20cm) in the outermost region of Young Sound (NE Greenland). Photo: Jakob Sievers.
Together they allow for calculation of the average flux in an upwind area in front of the tower. This area will vary in size depending on the height of the tower and wind-conditions. One of our instrument towers are shown in Fig. 3. From a mathematical standpoint the method is very simple, but it requires a number of quite complicated assumptions concerning the characteristic wind-patterns of the environment in question. Often these assumptions are not discussed in detail in papers. During my PhD I found that because most fluxes in a sea-ice environment are so small the critical assumptions began breaking down. It seemed that nearly all observations reflected large-scale meteorological patterns and flow-characteristics of the topography instead of fluxes in the local area of interest. Realizing this, I successfully developed and tested a very comprehensive data-analysis method to disentangle contributions of interest and contributions which were not reflective of the local environment of interest. Due to the technical nature of this new method I will not elaborate here, except to say that it was recently published in the Journal of Atmospheric Chemistry and Physics. Subsequently I was able to analyze simultaneous observations of CO2-fluxes and environmental parameters such as site energy balance and wind-speed to achieve a better understanding of some basic causal relationships for CO2 fluxes in a sea-ice environment.
Because this field of study is so new, and in-situ experiments are so challenging, much work is still needed but hopefully we will soon have a sufficiently detailed understanding of the physical and biogeochemical factors driving CO2 fluxes in the sea-ice environment, to be able to develop a model relationship and upscale that to all polar regions in which sea-ice exist.
Figure 4: An unexpected challenge during fieldwork: invasion by sled dog pups. Photo: Karl Attard.
I would like to leave you with one final picture illustrating a somewhat unexpected challenge during our experiment: having to reclaim our instruments and tools from the sled dog pups (Fig. 4).
Jakob Sievers ( Arctic Research Centre / Aarhus University) has just completed his PhD at Aarhus University in Denmark as part of the DEFROST project. He is interested in the physical and biogeochemical drivers of CO2 cycling in sea-ice environments and the development of flux models and flux observation methods under these challenging circumstances. He is currently seeking funding for the purpose of continuing his research in northern Norway.
Last hundred meters until ZAC_S, the middle station on A. P. Olsen ice cap. (Credit: Daniel Binder)
– In fieldwork, you have no average. You just have extremes.
When Daniel spoke his mind out loud we were facing a bright sunny day coming in from the opening of our tent. We were very glad to see that and ready to engage with our glaciological tasks. Our camp site was at the immediate fore field of the A. P. Olsen ice cap in Northeast Greenland. We had arrived there the previous evening and had two days left to spend for our science up on the ice. But, on Saturday 30 August, we had to return to Tyrolerfjorden, no-matter-what. It had to happen in one-go, which means a 12-hour hike, 30 kilometers, carrying everything. Our appointment with Kenny was 00:30 hours at its narrow coast, so he can provide us a safe passage with the boat back to the ZERO station. The weather was closing in again on Sunday and with four days of supplies left, we just had to make things happen.
Arctic fieldwork: Pose and reality. (Credit: Daniel Binder)
Daniel’s statement is very funny because it is actually very much true. Polar scientists always post their greatest photos, where they look like awesome polar explorers, implying that everything was completed like piece-of-cake. I do that too. But, there is always the other side of every story. Any fieldworker in the Arctic can verify that no matter how much experience you have or how hardened you have become through the years, every new mission is absolutely unique and different in many ways from all the previous ones. You have to prepare yourself the best way you can and when the time comes, perform your absolute best. Then, you have to also just hope for the best.
The initial plan was simple really. Two glaciers on the Northeast coast monitored by two institutes, ZAMG and GEUS, to be visited by a two-person mission, one from each institute, right? The team would be an alpine glaciologist with experience in the Austrian glaciers and an ice sheet glaciologist with experience in Greenland, both familiar with Zackenberg. End-of-summer mission implies that there is no sea ice in the fjords, so the team would have to hike everywhere. It also implies that there will be limited if any snow cover on the ice fields. Right…
When we began the first part of the mission on Freya glacier, the reality was quite different from our expectations. The biggest part of the glacier was still covered in snow. We were glad to see that, since it implied a positive mass budget year for Freya. On the other hand, since this was unexpected and we didn’t have our snow shoes with us, every step that we made was a struggle with the snow cover trying to swallow our legs while we are carrying all our equipment. Myself, I am what Daniel calls a “spoiled glaciologist”. Lightweight guy, I am definitely not as strong as he is, always riding on helicopters, twin otters and ski-doos. Seeing this genuine mountaineer also exhausted at the end of that first day on Freya made me feel a bit better about my performance. Of course, he was carrying about 10-20 kilos more on his back. Nevermind that.
Map of the wider region of Zackenberg (Geodætisk Institut).
Sleeping on the side moraine of Freya inside bivouac sacks was also a new experience for me. We were glad not to experience fierce weather, so it was overall not too bad. But the fact is that in a bivouac, you end up quite quickly in a pool of liquefied water vapor that rains down on your face. Remedy is not too easy since as soon as you open the sack, you are exposed to the freezing glacial air. Fever in the morning was guaranteed for me.
Back at the ZERO station and before the hike to A. P. Olsen land, our preparations definitely included snow shoes. The previous days on Freya, we were able to spot the Argo glacier, the East-flowing glacier of the A. P. Olsen ice cap, on the horizon. It seemed to have an extended ablation zone with no snow cover, but since our plans included a visit in the upper GlacioBasis station, we thought that snow shoes would come in handy. As it turned out that was a really wise decision.
On Saturday 23 August we began the second part of our mission. Kenny and Lars dropped us off with the boat at the north coast of Tyrolerfjorden, west of Zackenberg and opposite of Eiger on the Clavering island. The weather was not inviting, cloudy atmosphere with small droplets falling now and then, but nothing too alarming. Our greatest concern at that time was crossing successfully the river at Store Sødal that may or may not be raging and full of water. As it turned out, crossing the river was not too challenging, since the flow at the end of the summer season is significantly reduced. But, the persistent cloud cover had gotten very thick by early evening and resulted in rain and eventually a storm.
Hard tasks and rewarding views (Credit: Babis Charalampidis).
While being in the proglacial valley of the Argo glacier, we were still closer to Store Sødal than to the ice cap when we decided to set camp and take shelter from the storm. We were definitely glad to get a bit dry, but we knew that this was a far from ideal situation. In this region, a lot of furry animals like to hang out. Snow foxes, arctic hare, but also bigger ones: muskoxen, polar bears… Any close encounter with them was far from our desires and although we were equipped with a flare gun and a rifle, one always prefers to return them unused, when one gets to return. We could only hope that our training and instinct would serve us well, should the circumstances require it.
Sleeping in the tent was frustrating. Every noise from outside – the wind, rock falls, the river – were keeping us from relaxing and enjoying our sleeps. In the morning, the storm was still going on. What we couldn’t have guessed at the time is that it would last for more than three days. Our initial awareness turned into prolonged sleeping sessions. In the interest of carrying less weight, we didn’t have with us any books or card games. Our daily routine included frequent chats during coffee times that intervened between our 2-3 hourly naps. A big moment every day, was 8 pm when we would call Kenny to let him know we’re doing fine and learn the weather forecast. Sadly, we had to hear the words: “Still stormy forecast, boys” quite a bit. The mood would catch up later in the evening when we would have our modest dinner and finish the day with cognac and cigarettes.
Good times, bad times (Credit: Babis Charamlapida).
The time came when we heard good news: “Tomorrow, Wednesday 27th at noon sky clears up, boys”! And so it did. But, hiking after such a prolonged period in horizontal position was not something to derive pleasure from. By the end of that day, exhausted as we were, we managed to set camp at the very front of the glacier. Having wasted three days of supplies, we knew that we wouldn’t make it to the upper station. But, also one glimpse at the glacier predetermined that we will be slow again: The rain storm at the bottom of the valley was in fact a snow storm at the ice cap. The snow cover was everywhere at least half a meter and although we would be faster than on Freya with the snow shoes, we wouldn’t be as fast as we had hoped.
We successfully completed most of our tasks on A. P. Olsen and we definitely enjoyed this expedition. The scenery is always breathtaking and after all, this mission was more like an adventure of two friends than conventional glaciological fieldwork. But, it is also a fact that we overworked ourselves.
Last day on A. P Olsen and last hours of hike the next day before our pick-up from Tyrolerfjorden (Credit: Babis Charamlapida).
It is always good to remember that some moments throughout the process can be quite tough. In the end, this is probably the case with everything in life. The journey teaches you a few things. I will never forget the pain all over my body after the last hike from the ice cap to Tyrolerfjorden, racing against the clock on very challenging terrain with full backpacks. I will never forget the sense of trust that was developed between me and Daniel, how well we collaborated, coexisted and in a sense completed each other on this trip. Finally, I will never forget to have always a small book and a deck of cards with me.
Babis Charalampidis (GEUS/Uppsala University) is an Uppsala University PhD student within the SVALI project, based at the Geological Survey of Denmark and Greenland and supervised by Dirk van As. He is interested in the Greenland ice sheet’s mas budget, particularly the link between energy balance and subsurface processes such as percolation and refreezing. He studies the changes of the lower accumulation area of the southwest of the ice sheet in a warming climate, based on in situ observations.
The Tibetan Plateau – area: 2.5 million km2, mean elevation: 4,700 m a.s.l., surrounded by a series of high mountain ranges that are home to some of the world’s highest peaks: Himalayas, Karakoram, Pamir, Kunlun Shan. Considering these characteristics and the unique cultural heritage of Tibet the decision was easy when I was asked if I am interested working in a project on the regional patterns of glacier change on the Tibetan Plateau. And of course, we had to do a lot of field work to collect atmospheric and glaciological data :-). Between 2009 and 2012 we could realise seven field campaigns over three to four weeks to two different glaciers.
The Tibetan Plateau with location of the studied glaciers. The red stars mark the glaciers with in-situ measurements. Map by T. Bolch.
The journey always started at Lhasa airport. When leaving the plane I usually felt a little bit dizzy. Who wonders, air pressure is only 65% of that at sea level. In the following days in Lhasa every single time when walking up to the 3rd floor of our guesthouse at the Institute of Tibetan Plateau Research (ITP) I remembered that I was at 3,700 m a.s.l. By now I was glad that our schedule said that we stay in Lhasa for three nights before heading towards the snow and ice! Enough time to prepare our instruments, food and other equipment and to enjoy the tourist life… including headache and diarrhoea.
Glaciers on the Tibetan Plateau are usually terminating above 5,000 m a.s.l. and are only accessible by foot. Together with Chinese drivers and our colleagues from the ITP we left Lhasa by car, either for a one day ride to the north, to Nam Co Lake, and then another hiking day to Zhadang glacier (5,500 m a.s.l.). Or we went on a three day drive to the west, to the Kailash region, also followed by a one day ascent to Naimona’nyi glacier (5,600 m a.s.l.).
Local Tibetan people at Naimona’nyi glacier. Credit: Benjamin Schröter.
Generally, we spent two to three days in between to adapt to the altitude. With the support of local Tibetan people and yaks or horses we managed to bring all our stuff up to the glacier. I was always thankful only having to carry up myself and a small backpack :-).The torture of the ascent (at least for me) was totally forgotten when the tents were set up and we were rewarded with a great view down to the plateau (see picture at the top; camp at Naimona’nyi glacier. Credit: Benjamin Schröter).
However, we did not walk up to enjoy the landscape but to set up automatic weather stations (AWS) on or near the glacier and to conduct additional glaciological measurements. The AWS measure various atmospheric as well as surface and subsurface parameters. We also set up two time-lapse camera systems that took daily pictures of the glacier over three years. My colleagues at TU Dresden (Germany) geo-referenced and orthorectified these pictures to derive a daily snow line.
AWS at Naimona’nyi glacier in 2011. Credit: Christoph Schneider.
Usually nights up there were cold and restless and the days were quite exhausting. Air pressure drops to 50% of that at sea level. Thus, most of us were really happy when we successfully finished our measurements and repair work and walked down again after a few days to one week at the glacier side.
AWS at Zhadang glacier; left: 2009; right: after the ablation season in 2010. Credit: Christoph Schneider and Fabien Maussion.
When returning home in the office the real work was only just beginning. We set up a physically-based ‘COupled Snowpack and Ice surface energy and MAss balance model’ (COSIMA) that accounts for subsurface processes like melt water percolation, retention and refreezing. The collected in-situ measurements are used to calibrate, run and evaluate the model. Forced with atmospheric model data (High Asia Refined analysis; HAR) we then applied the model to five glaciers on the Tibetan Plateau (see map above). From every regional study we obtained a 10-year time series of glacier-wide surface energy and mass balance components. This data set helps us to further understand the role of the different energy and mass balance components for glacier change in the different climate regions of the Tibetan Plateau. We also hope to increase the knowledge on the various driving mechanisms for energy and mass balance on Tibetan glaciers.
Schematic overview of COSIMA by E. Huintjes.
Illustration of the ‘COupled Snowpack and Ice surface energy and MAss balance model’ (COSIMA). Tair: air temperature; RH: relative humidity; ws: wind speed; N: cloud cover; ρair: air density; SWin: shortwave incoming radiation; SWout: shortwave outgoing radiation; α: albedo; LWin: longwave incoming radiation; LWout: longwave outgoing radiation; Qsens: turbulent sensible heat flux; Qlat: turbulent latent heat flux; Qmelt: energy flux for melting; QC: conductive heat flux; QPS: energy flux from penetrating SW radiation; Ts: surface temperature; Tb: bottom temperature; Ti: temperature of the snow/ice layer i; ρi: density of layer i; wi: liquid water content of layer i.
Eva Huintjes is PostDoc at RWTH Aachen University, Germany. In December 2014 she finished her PhD on ‘Energy and mass balance modelling for glaciers on the Tibetan Plateau – Extension, validation and application of a coupled snow and energy balance model’ supervised by Prof. Christoph Schneider. She is interested in understanding the different regional patterns of glacier surface energy and mass balance components and their driving mechanisms on the Tibetan Plateau and in other glaciated regions. Currently she is applying the model to glaciers in southeastern Tibet to reconstruct Little Ice Age climate conditions and to glaciers in the Tianshan (northwestern China).
Wahlenbergbreen, Svalbard, in full surge mode (credits: Heïdi Sevestre)
Surge-type glaciers are the bi-polar member of the family of glacier dynamics. Every now and then they go into a complete fury and nobody really understands why.
What are surge-type glaciers?
Surge-type glaciers typically go through what we call the “surge cycle”. It is divided into two phases; a long quiescent phase during which the glacier is more or less dormant, followed by much shorter phase called “the surge”. Glacier velocities during the surge can typically reach 100 to 1000 the quiescence velocities. Velocities of up to 40 m per day were measured in Alaska during the surge of Variegated glacier.
The duration of the surge cycle varies from region to region. It tends to average around 20 years in Alaska, and 100 years or more in the Arctic.
What really triggers the surge of glaciers has always been an enigma in glaciology. Their unpredictable behaviour, and the dramatic and dangerous nature of the surge phase have always prevented extensive fieldwork to collect much needed in-situ data. Only a handful of studies have managed to obtain field data on glaciers before, during and after the surge of a glacier.
Distribution of surge-type glaciers in the world. Normal glaciers are blue, surge-type glaciers are represented by pink dots (credits: Sevestre and Benn, submitted)
Where are they found?
Surge-type glaciers are distributed in a “non-random” fashion, meaning that they do not uniformly pepper all the glacierized regions on Earth, but contrarily gather in narrow clusters only found in some regions. We think that cracking the code of their distribution might lead us to a better understanding of the causes of surging.
A strong concentration of surge-type glaciers can be found in the sub- and high-Arctic, namely Alaska, Arctic Canada, Greenland, Iceland, Svalbard, Novaya Zemlya and Karakoram. Another popular area for these glaciers is western central Asia with the Karakoram, Tian Shan and Pamirs. Sporadic clusters of a few individuals have also been identified in the Andes, Caucasus and Kamchatka (See Fig. 1).
Our contribution to the question:
A large part of our work has consisted in building a global inventory of all observed/identified surge-type glaciers in the world. This has enabled us to perform the first global statistical analyses on these glaciers. Comparing the geometry and climatic distribution between normal and surge-type glaciers has yield very interesting results.
Fieldwork has also been an essential component of our work. As a group fully based in Svalbard, we have no excuses not to do get out in the field and collect top quality data. Svalbard is actually of huge interest for us as the population of identified surge-type glaciers represent 20% of all the glaciers on the archipelago.
By using a Ground Penetrating Radar (GPR) we have been able to look at glacier thickness and ice temperature on 15 different surge-type glaciers. These attributes are essential to map the thermal structure of the glaciers and understand further their potential surge mechanisms. As extensive as this may sounds, GPR-ing glaciers in Svalbard is actually quite an enjoyable task to do as the whole system can be towed by a snow scooter, and hundreds of kilometres of data can be collected in just a couple of days (see figure 2).
An “all seeing eye” is our best ally to observe spatial patterns of surging on the archipelago. Remote sensing data is really the only way we can catch surges in their very early stages. At the end of last year, we acquired pairs of TerraSar-X images covering most of the archipelago, and derived surface velocities from there. We discovered that no less than 17 glaciers are currently actively surging!
Driving in straight lines on a glacier in Svalbard = collecting GPR data (credits: Nick Hulton).
So… why do they surge?
First, we know how glaciers can surge. They can sustain such high velocities over months or years by having water at their base, lubricating their movement. But as soon as the water escapes, the surge terminates.
Over the past decades, two models of surging have been developed, each trying to understand how glaciers with different thermal structures can surge. Glaciers can either be “warm bedded” meaning that ice at their base is just at the point of melting; or “cold-bedded” if their ice is below the point of melting. Glaciers with a fully warm base have been observed to surge, as well as glaciers with a warm core surrounded by cold ice. The first model suppose that a switch in the configuration of the basal meltwater drainage system could lead to a surge, while the second suggests that surging could be caused by a change in the basal temperature from cold to warm. In both models, water eventually becomes trapped under the glacier, removing any friction at its base, and enabling it so move at high speeds.
There is still a lot to understand about these glaciers, and we hope that our results will cast a new light on the weird and wonderful world of surging glaciers!
Time lapse imagery
Follow this link to see a time lapse of the surge of Paulabreen, Svalbard:
Heidi Sevestre is a PhD student based at the University Centre in Svalbard and supervised by Prof. Doug Benn and Prof. Jon Ove Hagen. Heidi is interested in glacier dynamics, particularly the mechanisms of glacier surges. She studies the global distribution of surging glaciers and their regional specificities, while field data is collected in Svalbard.