Ice fog—a curtain of tiny ice crystals suspended above the earth’s surface—reduces visibility and makes air travel treacherous.
How ice fog forms and why it persists is not entirely understood, and this has led to inaccurate forecasts, particularly visibility predictions that are critical for safe aviation and navigation.
To tackle this problem, a team of engineers from the University of Notre Dame is leading a multi-institutional research project in Utqiagvik (formerly, Barrow), Alaska. Their mission: to uncover the exact microphysical processes and environmental fluid mechanics behind ice fog’s formation.
“Ice fog is one of the least understood forms of fog because it involves all three forms of water—vapor, ice, and liquid droplets—all mixing within complex turbulence,” said Harindra Joseph Fernando, the Wayne and Diana Murdy Endowed Professor of Engineering and Geosciences at the University of Notre Dame and principal investigator of Fatima-IF, the Fog and Turbulence Interactions in Marine Atmosphere Ice Fog project.
Utqiagvik, located on the Arctic Ocean, is the northernmost community in the United States. Polar bears roam the windswept, snowy expanses; beluga and bowhead whales migrate through the krill-rich waters. The area’s extreme cold, long polar nights, and unique position on the boundary between land and sea make it an ideal place for Fatima researchers to study how ice fog forms.
“Good visibility measurements are essential for our research,” said Jay Hyde, field technician for Notre Dame’s Environmental Fluid Mechanics Laboratory. “The Vaisala FD70 uses light to measure particulate and its velocity, so we can know how big the atmospheric particles are that are lowering visibility and how fast they’re traveling.”
A weather balloon launches four times a day to provide a data-rich vertical snapshot of atmospheric conditions, and an array of high-resolution particle imaging and analysis sensors reveal atmospheric processes in microscale.
On November 18, Polar Night descended on Utqiagvik, plunging the researchers’ world into darkness until January 22, 2026.
“We hear trucks and snow machines from town three miles away, the crunch of snow, the wind blowing through structures,” said Hyde. “The snow isn’t well packed, so even a moderate wind can pick up enough frost from the surface to make it hard to see more than a few hundred meters.”
“All the caribou, moose and birds left in September or October. There’s an arctic fox den by the site where the sensors are deployed. Sometimes, they come out to hop around, but mostly we see just their tracks in the snow.”
Despite the darkness and relative isolation, the Notre Dame researchers say they find inspiration in the project posters displayed in the halls of Iḷisaġvik, the tribal community college near the research installation. “Good science has been carried out here for a long time. If they can do it as a career, we can handle a month,” said Hyde.
The Fatima teams have already reported some previously missing details about how fog transitions from a slurry of ice crystals and supercooled liquid to dangerous ice-based fog, said Fernando. The research campaign, he said, is well on its way to obtaining the missing data that will make a comprehensive understanding of ice-fog dynamics possible.
The Fatima-IF project was funded by the Office of Naval Research Grants N00014-21-1-2296 and N00014-25-1-2525 as well as the Atmospheric Radiation Measurement (ARM) User Facility, a U.S. Department of Energy (DOE) Office of Science user facility, managed by the Biological and Environmental Research program.
Life and Work in Utqiagvik, Alaska
—Karla Cruise, Notre Dame Engineering; photos courtesy of Matthis Chabert D’Hières, Marilyn Dunbar, and Harindra Joseph Fernando.