Tracking Arctic Sea Ice from Space

In an effort to understand why sea ice is rapidly disappearing in the Arctic, researchers from the University of Maryland Department of Geographical Sciences are utilizing the latest satellite-based technology to measure detailed changes on the sea ice cover such as individual melt ponds, ridges, cracks and floes.

Using data from ICESat-2—a NASA satellite launched in 2018 designed to measure ice, cloud and land elevation—UMD researchers and collaborators from the University of Alaska Fairbanks were able to observe in high resolution how arctic sea ice cover melted, drifted and grew.

“One of the most striking environmental changes underway in the Earth system today is the loss of sea ice in the Arctic,” said Sinead Farrell, an associate professor of geographical sciences who led the research. “Anomalously warm weather in the Arctic earlier this year caused sea ice to retreat to its second-lowest level in the modern record. Using the new remote-sensing capability provided by ICESat-2 allows us to observe what is happening to the complex sea ice surface in a way that was simply not possible previously.”

Findings published October 21 in Geophysical Research Letters revealed the NASA satellite has the ability to probe one-meter-deep summer melt ponds—something never accomplished before using a space-based instrument—which could help scientists track how much ice is melting from year to year. Additionally, the researchers were able to measure narrow pressure ridges in the ice just 7 meters wide and to track small ice floes (floating chunks of ice) measuring only 20 meters across. They mapped the surface of the ice across the Arctic and discovered that the older ice gets, the rougher it becomes.

“It is exciting to see groundbreaking results coming out of the ICESat-2 dataset so quickly,” said Jackie Richter-Menge, a research affiliate at the University of Alaska Fairbanks. “It’s on track to be a game-changer when it comes to observing and understanding the impacts of the warming environment on the dynamic arctic sea ice cover.”

Next, the researchers hope to use ICESat-2 observations together with field measurements in the Arctic to investigate how the sea ice cover evolves and changes over time. This will help to improve models used to predict the fate of arctic sea ice.

The research team also included Kyle Duncan, a Senior Faculty Specialist at the UMD Earth System Science Interdisciplinary Center; Ruohan Li, a graduate student in the Department of Geographical Sciences; and Ellen Buckley, a graduate student in the Department of Atmospheric and Oceanic Science.

October 21, 2020