Tracking water vapor over Greenland’s ice sheet with a drone
A drone experiment over the Greenland ice sheet has made it possible for the first time to take detailed measurements of water vapor in the atmosphere over Greenland. This new technology could contribute to improving climate models and help to better estimate Greenland’s future contribution to global sea level rise.
Greenland is constantly losing ice – most of it through meltwater and calving glaciers. But there is also a barely visible process that is difficult to quantify: Sublimation – the direct transition of ice into water vapor without it melting first.
However, this part of the water cycle is still poorly understood. Where exactly the rising water vapor comes from, how it behaves in the atmosphere and whether it later falls again as snow over Greenland or leaves the system permanently has been largely unclear until now.
An international research team led by PhD student Kevin Rozmiarek from the University of Colorado Boulder has now made significant progress. The researchers used a custom-built drone to collect detailed water vapor samples over the Greenland ice sheet for the first time. Their study was published on March 14, 2025 in the journal JGR Atmospheres.
Until now, collecting aerial samples over the vast Greenland ice sheet has been time-consuming, expensive and often only possible with manned research aircraft. However, as in many other areas of science, drones are proving to be an efficient tool for closing research gaps in regions that are difficult to access.
To collect the atmospheric samples, the team equipped a fixed-wing drone with a three-meter wingspan with sensitive measurement instruments and conducted 104 flights from the East Greenland Ice-Core Project drilling camp in the island’s interior during the Arctic summer of 2022.
The aim was to collect air samples at different altitudes – up to 1,500 meters above the ice surface – and to analyze the isotopic composition of the water contained in the atmosphere. Depending on their origin, the water molecules contain different isotopes of hydrogen and oxygen, which provide clues as to where the water comes from and where it is moving to.
“We will be able to understand how water moves in and out of Greenland in the next few years” said Kevin Rozmiarek, lead author of the study, in a university press release. “As a major freshwater reservoir, we need to understand how Greenland’s environment is going to change in the future.”
While extensive data on precipitation and surface water in the Arctic already existed, little was known about water vapor. It also remained unclear how much of it is actually produced through sublimation and what happens to it afterward. Earlier estimates suggest that in some parts of Greenland, up to 30 percent of the surface snow could enter the atmosphere this way during the summer.
When the researchers compared their results with existing climate models, they found that precipitation had been significantly underestimated. By integrating the new isotope data, they were able to improve the model, resulting in a more accurate representation of the water cycle over the ice sheet.
“It’s really important to be able to predict what’s going to happen to Greenland in the warming world as accurately as possible,” explains Rozmiarek. “We demonstrated how useful water vapor isotope data is by successfully improving an existing model.”
These findings are of great importance, as Greenland plays a key role in the global climate system. The ice sheet contains around eight percent of the world’s fresh water. According to the US climate agency NOAA, the island has lost over 5 trillion tons of ice since 1992 – around 55 gigatons between autumn 2023 and autumn 2024 alone. And the ice continues to disappear: for the 28th year in a row.
“It’s like we just figured out how to discover fingerprints at a crime scene. This is a concrete step forward in understanding where water is going and where it is coming from in this important system at a time when we need it most,” says Rozmiarek.
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