Data shows Great Lakes ice coverage is slowly rising after hitting historic lows earlier this month.
According to the National Oceanic and Atmospheric Administration's (NOAA) Great Lakes Environmental Research Laboratory (GLERL), ice coverage on the Great Lakes totaled 12.18% on Feb. 19 after spending weeks in the single digits.
As of Feb. 19, the coverage on each of the lakes was measured at:
- Lake Superior - 11.95%
- Lake Michigan - 10.88%
- Lake Huron - 20.03%
- Lake Erie - 3.31%
- Lake Ontario - 2.32%
Researchers say on Feb. 11, it hit a historic low with total coverage at just 2.69%, with coverage on each of the lakes measured as follows:
- Lake Superior - 1.7%
- Lake Michigan - 2.6%
- Lake Huron - 5.9%
- Lake Erie - .05%
- Lake Ontario - 1.7%
According to the researchers, the Feb. 11 date had Lakes Erie and Ontario at or tied with their individual historic lows for the date, which is essentially ice-free.
“We’ve crossed a threshold in which we are at a historic low for ice cover for the Great Lakes as a whole,” GLERL Pyshical Scientist Bryan Mroczka said in a statement. “We have never seen ice levels this low in Mid-February on the lakes since our records began in 1973.”
The 2023-24 winter season has been unusually warm across Michigan, which the NOAA said has resulted in slow ice formation. Arctic air in parts of January saw ice coverage across the lakes increase, with total coverage peaking at 16.02% on Jan. 22.
However, the NOAA said maximum ice cover for the year usually peaks in late February or early March, and on average, it's about 53%.
The NOAA's 8-14-day outlook from the Climate Prediction Center predicts above-average temperatures for all of Michigan through at least early March.
Impact of minimal ice coverage
According to the NOAA, ice coverage has a big impact on people living in communities around the lake, whether they rely on ice fishing or other outdoor sports that can only happen in thick ice.
At the same time, there are some fish species that use the ice for protection from predators during spawning season, and there is evidence ice plays a role in regulating biological processes in the water.
The NOAA said minimal ice also makes the shoreline more susceptible to erosion due to high winds and waves, as the ice dampens large wave action.
It can also lead to more lake-effect snow, and ice cover also impacts water level fluctuations.
The relationship between ice cover and Great Lakes water level fluctuations is complex, explains GLERL researcher Lauren Fry.
“Evaporation happens when there is a large temperature difference between the air and water,” says Fry. “We tend to see the highest evaporation rates during the fall and early winter when the surface water is relatively warm and cold blasts of Arctic air enter the basin," GLERL Researcher Lauren Fry said in a statement.
