Draw wire ice ablation trackers: measuring ice melt and motion

Several months ago we installed 4 new draw wire ice ablation trackers (DWIATs) on the Greenland ice sheet on behalf of the Geological Survey of Denmark and Greenland (GEUS) and the Institute for Marine and Atmospheric research Utrecht (IMAU). The DWIATs monitor surface lowering by melting, movement as a result of ice dynamics, and temperature (inside the sensor box). Melt and motion are interlinked, as more melt leads to greater amounts of water at the glacier bed, which can result in increased glacier motion. The accuracy of localisation by GNSS satellites is accurate, allowing for the identification of periodical speed-up events. The DWIATs can be further tailored to your needs by adding additional sensors.

DWIAT installation (photo Maurice van Tiggelen)

DWIATs are very rugged, and easy to install: 1) Assemble the tripod with hex keys. 2) Mount the sensor/logger box. 3) Drill a hole max. 14 m deep. 4) Lower the draw wire into the hole. 5) Switch on the system. The units’ batteries can be shipped without dangerous goods declaration, and allow solar charging at temperatures (well) below freezing. Even without recharging during dark winter months the trackers keep functioning for several months. Both software and hardware safeties are built into Greenland Guidance instruments; double measures to prevent battery discharge beyond critically low levels.

The units recently installed in Greenland transmit their data through the Iridium satellite network that has coverage at even the northern- and southernmost latitudes. The data feed straight into the Greenland Guidance data portal where they are displayed and made available for download on a private web page. If the instrument owners approve, the data can also be graphically displayed on (but not downloaded from) the public data portal. Naturally, the DWIATs also store their measurements locally in the datalogger, ready for read-out during the next field visit in one or several years.

The DWIAT data currently featured in our public data portal belong to GEUS who monitor the Greenland ice sheet mass balance in the PROMICE project.

Borehole under ice: instrument maintenance and science support

About a decade ago a consortium of scientific and commercial organisations led by SKB in Sweden drilled a borehole in the bedrock underneath the Greenland ice sheet. Their goal: to quantify the level of interaction between the ice sheet and the groundwater below. To achieve this they drilled a 651 m long borehole angled underneath the ice sheet and equipped it with instruments. It is the first ever borehole drilled underneath an ice sheet – a truly unique project.

The location of the borehole underneath the ice sheet

Recently, SKB asked Greenland Guidance to perform instrument maintenance to ensure the continuation of the time series during a period when travel to Greenland is complicated by the COVID-19 pandemic. We gratefully accepted the task. While on site, we saw an opportunity to also shoot some drone footage.

The measurements taken in the borehole form a long, uninterrupted, and scientifically surprising time series. With the help of scientists from the University of Montana and others, SKB has written up a manuscript that is currently under review in a scientific journal. Greenland Guidance helped with the interpretation of the borehole data in terms of ice melt and movement, and is proud collaborator on the study.

Ice sheet weather station maintenance along the iconic K-transect

This year we took part in a scientific expedition to the southwestern region of the Greenland ice sheet. Representing the Geological Survey of Denmark and Greenland (GEUS), and in collaboration with the Institute for Marine and Atmospheric Research (IMAU), we serviced instruments and stakes placed at 10 different sites on the ice sheet. We accessed the remote sites, up to 140 km into the ice sheet, by Air Greenland helicopter.

GAP/PROMICE weather station KAN_U in 1 m of snow

The scientific instruments by GEUS and IMAU monitor the interaction between the atmosphere and the ice sheet. In other words, they determine how much ice melts, and what is causing the melt: which combination of warm weather, solar radiation, strong winds, etc. The GEUS instruments are part of the measurement networks of the Greenland Analogue Project (GAP) and the Programme for Monitoring of the Greenland Ice Sheet (PROMICE). We even installed 4 of our own draw-wire ice ablation trackers (DWIATs) – more about that in an upcoming news item.

The measurements are taken along the iconic K-transect, where ice sheet monitoring already began in 1990(!). The longer the times series, the more valuable it gets. Long climate records provide much needed context for measurements in individual years: if there is 5 m of ice melt – is it a lot (above average) or not?

Even though taking measurements over many years is crucial for climate science, it is not always an attractive option for funding agencies. So if you’d like to financially support the monitoring activities along the K-transect, it could make a large difference!

University of Lausanne sediment coring in a Greenland fjord

This september, a team of scientists from the University of Lausanne set out to collect sediment cores from the bottom of the fjord into which the glacier named Eqip Sermia calves icebergs. They contacted Greenland Guidance to help them find a boat with a winch that could lift the sediment cores from the bottom of the 200-m deep fjord to the surface. Finding a boat was easy, but finding a winch that would get the job done was more of a challenge. Especially in times of COVID-19 with life in Greenland coming to a standstill. But we managed to track one down so that the expedition could take place.

The scientists reported that “The expedition went great! We collect 35 sediment cores and things went well with the boat. It was a ton of work and a bit icy on the water by the end. It really went as good as we could have expected.”

Scientist processing a sediment core just winched onto the deck

University of Liège studies the wind power potential of Greenland

That’s the gist of it. And to be able to do so, three masts measuring wind and temperature were installed in the south Greenland fjord area by the University of Liège over the summer. These masts are ten meters tall – ten meters being the standard level for wind measurements. But in order to survive the fierce winter storms in the region, each mast had to be very sturdy, bolted into rock, and equipped with guy wires. Setting up such heavy masts is easier said than done.

Greenland Guidance helped out with various aspects in the early phases or the project, most importantly to obtain permits (site allocation), but not with the installation itself. For the installation the University of Liège’s team received help from the Northabout crew – the ship is sailing the northern waters for the Unu Mondo expedition to increase the visibility of the impact of climate change on the northern regions and its people. We’ve had the pleasure of staying on board their vessel and are keen to help them find scientific institutions to partner with in coming years.

The weather masts are in place and transmitting their data. Please check out the website of the Katabata Project for more information.

Greenland ice sheet monitoring at the K-transect

Greenland Guidance has several links to the iconic K-transect, where scientists have been measuring ice sheet surface mass balance for an astonishing 30 years. Not only are we building scientific instruments to be placed along the transect, we also have a history of performing maintenance on the existing infrastructure on behalf of the Institute for Marine and Atmospheric Research in Utrecht (IMAU) and the Geological Survey of Denmark and Greenland (GEUS).

The transect, consisting of 10 instrumented sites, is located along the western slope of the Greenland ice sheet, from the low-elevation ice sheet margin, up to an elevation of 1840 m above sea level. Both surface mass balance and weather/radiation observations are made, to be able to quantify ice loss, and to explain which processes (such as atmospheric warming) dominate this mass transfer from the ice sheet to the oceans.

The end of an era might be approaching as obtaining funding for the monitoring is becoming increasingly difficult. Even though the measurement time series is becoming more important with each added year – in Greenland there is nothing that compares. And even though many important scientific publications have relied on these data in the past.

That’s why SKB, the primary funder of GEUS’s efforts at the K-transect for the past 13 years, requested Greenland Guidance to construct a video with the aim to make more people aware of the climate and ice sheet science being done in Greenland, and to attract additional funding.

Support the monitoring efforts at the K-transect on the Greenland ice sheet

If you’d like to support climate science through this project, then do not hesitate to get in touch -> see the video for contact information. Or get in touch with us, and we’ll guide you to the appropriate people.

Support in development of drill to melt through Greenland ice sheet

Greenland Guidance provided insights in choosing the most durable parts for a drill being developed by the Geological Survey of Denmark and Greenland (GEUS). It’s tricky business as the melt-tip drill will generate high temperatures while melting its way through cold glacier ice. The drill development is for the HOTROD project headed by Liam Colgan, whereas Chris Shields is the project’s CTO. We were excited to be able to contribute to this project by choosing parts and shipping them over to GEUS. We’d love to see the drill in action in the field, either in 2020 or 2021.

Ice ablation tracker installed on Sermilik glacier, southern Greenland ice sheet

At the location where in 2010 the largest-ever annual ablation on the Greenland ice sheet was measured, we have now installed a Greenland Guidance draw wire ice ablation tracker – DWIAT in short. The site is located all the way at the southern tip of the ice sheet, where temperatures are relatively high in summer, and where the ice surface is incredibly dark, absorbing a large fraction of the sunlight. Measurements by the PROMICE automatic weather station network tell us that here typically 5-6 m of ice melt off each year – in addition to the snow that accumulated in the preceding winter – which is a lot compared to other Greenland sites. But in 2010 the weather station QAS_L observed a record-setting ablation of more than 9 m of ice here – that’s the equivalent of 3 floors of a building!

The ice ablation tracker with Sermilik glacier and fjord in the background. Latitude: 61.0 N.

To investigate the extreme melt at this site, PROMICE has started a collaboration with the Institute for Marine and Atmospheric Research (IMAU) of Utrecht University. With more instrumentation measuring air-ice interaction on site, tracking ice ablation became even more relevant for data interpretation. That is why the Greenland Guidance DWIAT now measures ablation along side the PROMICE weather station. With it’s reference weight drilled 10 m into the ice, this unit should be capable of recording ablation until at least late summer 2020 – unless 2019 or 2020 proves to be yet another major melt year.

Instrument checking after storage on ice

Mike MacFerrin, PhD (University of Colorado Boulder): “My instruments had been transported down from the Greenland ice sheet when I wasn’t around. I’ve had great experiences with the guys of Greenland Guidance in the past, so I had them check on my gear. They made sure that snow and extreme temperatures hadn’t damaged anything. Here’s a big thanks to Greenland Guidance for helping out!”

Weather station maintenance on the Greenland ice sheet

Late summer 2018, Greenland Guidance supported the maintenance of the automatic weather station network of the Programme for Monitoring of the Greenland ice sheet (PROMICE). The expedition took us past 4 weather stations in the region near Kangerlussuaq, where the countries largest airport is situated. The furthest station location was an hour flying away, on top of the ice sheet at 1840 m above sea level. Being dependent on Air Greenland helicopter transportation, and with a storm approaching the area, the work got squeezed into a shorter-than-ideal period, but successfully wrapped up nonetheless.