A 15-year project that captured critical measurements atop the Greenland Ice Sheet has ended. Scientists around the world are trying to understand how, and how quickly, Greenland is warming because ice melt there contributes to global sea level rise, impacting coastal ecosystems and communities around the world. ICECAPS helped to understand the important links between a changing atmosphere and the rapidly increasing melt.

The project, the Integrated Characterization of Energy, Clouds, Atmospheric state, and Precipitation at Summit (ICECAPS), is an international collaboration that has measured atmospheric properties at Greenland’s Summit Station since 2010. The project has significantly advanced scientists' understanding of clouds, radiation, surface energy, and precipitation in a region with very few observations. 

“To understand the region’s future, you need to understand the interactions between clouds and the surface,” said Matthew Shupe, research meteorologist with CIRES and NOAA’s Physical Sciences Laboratory. “Our findings have implications for the fate of ice throughout the Arctic.” 

ICECAPS researchers use high-tech instruments to measure clouds, radiation, precipitation, ice crystals, and more. Over its 15-year duration, ICECAPS added new or enhanced research platforms to address evolving science goals.

For example, to better study the atmosphere-surface interactions driving surface melt, CIRES scientists built and deployed a new autonomous research platform in 2024 at the Raven Camp remote station several hundred miles away, a location that melts frequently. The platform ran on renewable energy, operated on its own without humans, and observations were processed and transmitted via satellite to researchers back to the team’s home institutions.

The project produced a trove of first-of-its-kind data that has significantly advanced the understanding of Arctic atmospheric processes, especially clouds, precipitation, and the surface energy budget. The data was key in helping scientists understand that low-lying clouds over the ice sheet could drive significant melt events. These clouds allow the sun's energy to pass through to the surface while also trapping heat, creating a powerful warming effect. 

Researchers also discovered these thin, low-lying clouds occur 30-50 percent of the time in the summer, both over Greenland and across the Arctic. Current climate models tend to misrepresent the occurrence of liquid-containing clouds in the Arctic, which limits those models’ ability to predict surface melt across the Arctic at a time of rapid change.

ICECAPS funded the research for more than a dozen graduate students, the next generation of polar scientists, and produced more than 50 publications in scientific journals. ICECAPS is a collaborative project led by CIRES at the University of Colorado Boulder, Washington State University, Vanderbilt University, University of Wisconsin-Madison, Boise State, Dartmouth University, University of Leeds, and NOAA. 

As the project wraps up, Shupe and his team are excited to build on the advances made by ICECAPS.

“While this phase of ICECAPS ends, we are only just beginning to unravel the processes of Greenland melt,” Shupe said. “Exciting new technology will enable us to access, measure, and ultimately understand how melt unfolds across Greenland.”