International team probes ice sheet-atmosphere system in Greenland “percolation” zone
Researchers brave cold, blustery conditions to install scientific instruments that monitor heat, moisture, ice structure
On May 1, 2024, an engineer, a graduate student, and three research scientists disembarked a military airplane in the middle of the Greenland Ice Sheet with three large pallets of camping gear, tools, instruments, and half a million calories worth of food. Now, the team is braving extreme cold, blustery winds, and sore muscles as they install 25 instruments to observe changes in the ice sheet-atmosphere system during the summer melt season.
“This project is specifically examining the processes related to large-scale atmospheric circulation patterns, how they bring heat and moisture to the ice sheet, and the subsequent implications for surface melt and precipitation,” said Matthew Shupe, a CIRES research scientist who works in both NOAA’s Physical Sciences Laboratory (PSL) and the CU Boulder-based National Snow and Ice Data Center (NSIDC). “Little is known about these atmospheric processes over Greenland and models struggle to represent them,” said Shupe, who is one of the five team members on the ice.
This summer, Shupe and the team are taking a closer look at the Greenland “percolation” zone where conditions on the ice sheet transition from dry snow to regular summer melt. As the climate warms and atmospheric patterns change, this region is expanding. When meltwater seeps into the spongy, porous ice layer or “firn” between the upper layers of snow and glacial ice beneath, it can refreeze, releasing heat that can alter the structure of the ice around it.
Andrew Martin (University of Leeds) digs the trench for the battery bank that will power the renewable system while Catherine Hebson (Washington State University) prepares the batteries.
“The MELT [MEasurements along Lagrangian Transects] project will be the first time that the complete coupled climate system is observed autonomously in this region,” said Michael Gallagher, a CIRES research scientist also affiliated with PSL and NSIDC, and team member on the ice. “Our observations will provide important insight into the changes happening as anthropogenic climate change continues to impact Greenland.”
The project is an extension of the Integrated Characterization of Energy, Clouds, Atmospheric state, and Precipitation at Summit (ICECAPS) project, which has been providing detailed observations of the ice sheet-atmosphere system in the cold high-elevation ice sheet zone for 14 years.
The field team is 16 days into their expedition. Hundreds of miles from help, the team of five is responsible for getting the ICECAPS-MELT monitoring instruments up and running. And they’ve been busy since their feet first touched the ice — from erecting tents and lifting heavy equipment to wiring electronics and digging holes (more than 30) to stabilize structures.
Von Walden (Washington State University) shoveling snow during a wind storm to make anchors for the solar panels.
“The cold and wind and snow are a challenge nearly every day,” Shupe said. “Fingers, toes, and noses get very cold, and thus work typically proceeds quite slowly, much slower than at more temperate locations.”
In the first week on the ice, the field team set up their camp and installed 16 solar panels and two wind turbines. The rest of their expedition will focus on the scientific instruments, which include radiometers, ground penetrating radar, GPS equipment, temperature probes, and radar systems, among others. The team has until May 20 to ensure everything is working correctly.
“[We’re installing] instruments and sensors measuring meters into the subsurface all the way to kilometers in the air,” Gallagher said. “And the science platform will be completely powered by renewable energy from the wind and sun.”
The ICECAPS-MELT field team installs and stabilizes a 14-foot wind turbine. “Raising the turbine took less than an hour but the holes took half the day,” Gallagher said.
Data about energy moving in and out of the ice, firn structure, temperature variability, precipitation, cloud cover, and more will be processed and transmitted out of Greenland, allowing the ICECAPS-MELT team to analyze the observations in real time, from any place in the world.
While only five ICECAPS-MELT team members are on the ice, the work would not be possible without the support of the rest of the team, spread across six institutions in the United States and the United Kingdom.
“It is not feasible for a single institute to conduct research on this scale and with this complexity,” Shupe said. “Each member institute brings a particular area of expertise, which helps us to understand the key components of a complex and interconnected set of processes.”
When the military plane returns to take the field team off the ice, the ICECAPS-MELT instruments will remain, collecting data from the subsurface, surface, and air above the ice until August 2024. The team is blogging about the fieldwork and sharing real-time data on a project website.
The ICECAPS-MELT project is funded by the US National Science Foundation and the UK National Environment Research Council, with support from the US National Oceanic and Atmospheric Administration (NOAA).
