CAMBRIDGE BAY — Researchers conducted the first real-life sea ice thickening experiments in Cambridge Bay, Nunavut, Canada, during the winter of 2024 to 2025. The study results were published May 22 in the journal Earth's Future.

The team set up eight test areas and three control sites in Cambridge Bay. They used submersible pumps, each consuming less power than a toaster, to flood the test areas with up to 8 inches (20 centimeters) of seawater. Some test areas were flooded once, while others were flooded twice. The control sites were not flooded.

By the end of winter, the test areas had grown up to 12.6 inches (32 cm) thicker than the control sites. Test areas that were flooded twice demonstrated greater thickening compared to those flooded only once. From late May to September, the sea ice in the test areas appeared brighter and exhibited slower melt rates than the control sites.

Edward Blanchard-Wrigglesworth, a research associate professor in the University of Washington's Department of Atmospheric Sciences, and Andrea Ceccolini, an honorary professor at University College London and CEO of Real Ice, explained the process. "The snow-water mixture freezes into a new layer of ice, while the reduction in snow insulation allows colder atmospheric temperatures to accelerate natural ice growth from below," Blanchard-Wrigglesworth and Ceccolini said. Real Ice receives funding from the U.K. government.

One control site was used for a melt pond drainage experiment during the spring, which involved drilling small holes in the ice to remove meltwater. This experiment resulted in brighter sea ice compared to the other control sites. Blanchard-Wrigglesworth and Ceccolini stated, "Practical applications [that already exist] include building ice roads and creating platforms for offshore oil exploration."

The researchers also commented on the broader implications of their findings. They said, "The broader implication is that these effects could enhance the Arctic's reflectivity through both increased surface brightness and longer-lasting sea ice." They added, "If similar results could eventually be achieved at larger scales, increased Arctic albedo could contribute to regional cooling, with potential knock-on benefits such as slowing permafrost thaw and reducing ice loss from Greenland."

Yearly sea ice extent in the Arctic has shrunk by 20% since 1979. A 2016 study indicated that covering 10% of the Arctic Ocean would require 10 million wind-powered pumps, while covering the entire Arctic Ocean would necessitate 100 million such pumps. In a 2021 study, researchers wrote, "The pumps must be deployed almost immediately, while there is still a sufficient area of sea ice over which to flood."