Researchers dug into historical temperature records from weather stations around the Great Lakes, the earliest from 1897.
Ice forms on the lakes when there’s lots of really cold days in a row.
So compiling temperature data from deeper into the past can help improve knowledge of where ice might have formed and for how long.
And that can help scientists do better research in the future, especially as things shift under climate change, says study co-author Ayumi Fujisaki-Manome at the University of Michigan.
“Lake ice is really part of the system, part of our life. And we've been seeing a lot of changes, a lot of variability in the recent years, and we still have some work to do.”
State fish biologists are already using the data to study declining whitefish numbers in the Great Lakes.
