New drone technology measures Greenland’s glacier fronts in winter for the first time

Thanks to new drone technology, a group of researchers has succeeded in examining the frozen fjords in Greenland in winter and making measurements that contribute to a new understanding of the relationship between the fjords and the Greenland Ice Sheet. What happens at the meeting between ice and fjord is important for calculations of the Greenland Ice Sheet’s mass loss and for our understanding of the conditions in the fjords, amongst other things.

The study is a collaboration between the Geological Survey of Denmark and Greenland, Aarhus University and the Greenland Institute of Natural Resources.

“Our measurements show that there is an outflow of freshwater at the glacier fronts in winter, and that the water probably comes from the bottom of the Greenland Ice Sheet. This has never been demonstrated before,” says Nanna B. Karlsson, professor at GEUS and leader of the project, the results of which are published in Nature Geoscience.

The measurements show the temperature and salinity of water at the glacier fronts and further out in the fjord. The new winter measurements are particularly important because most observations of glacier fronts originate from the summer period.

“Calculations and modelling often assume that there is little or no outflow of freshwater from glaciers to Greenlandic fjords in winter. Our study is an important step towards better understanding the conditions in winter,” says Nanna B. Karlsson.

Drone crosses impassable fjords

It is not easy to make measurements at the glacier fronts in the fjords, which are hard to access and often covered in ice during the winter season. The researchers have used a so-called UAV, an uncrewed aerial vehicle – also known as a drone. The drone has been essential for the researchers to be able to make the measurements.

“We developed a system with a drone that we could mount the measurement equipment on,” says Ebbe Poulsen, who is an engineer and drone pilot at Aarhus University and co-author of the study as well as a research article about the development of the drone published in HardwareX.

Top left: The drone is flying with the measuring device mounted. Top right: The drone lowers the measuring device into a hole in the ice. Bottom: Ebbe Poulsen inspects the drone, which resembles a small helicopter. (Photos: Karina Hansen et al., Søren Rysgaard.)

The drone made it possible to take measurements in holes in the fjord ice in places where it was not possible to set up other measuring equipment. The researchers also made manual measurements from the glacier front.

“Our measurements provide unique insight into the occurrence of subglacial melting at the glacier fronts and they give us an opportunity to understand the importance of this melting in winter,” says Søren Rysgaard, professor at Aarhus University and co-author of the article.

In 2021, Nanna B. Karlsson received DKK 1.4 million from the Villum Experiment for the project. (News item in Danish)

At the end of 2024, Nanna B. Karlsson received a grant from the Novo Nordisk Foundation of DKK 2.8 million for further work on the project.