This has been a frigid winter with polar vortices, snowfall breaking decades-old records, and widespread ice formation on the Great Lakes.
Lake Michigan was just over 93% covered with ice on March 8, setting a new record.
Ice near Chicago
Overall, the Great Lakes were just over
92% iced over on March 6,
not quite breaking the record.
Windrow ice near Chicago
The lakes are dynamic, so the ice breaks up, gets pushed around, and then stacked near the shore making elaborate formations.
Close shot of windrow ice
Peak ice coverage for each Great Lake this year:
Some reports stated that Lake Ontario has less ice coverage due to its volume-to-surface-area ratio, but this ratio is similar to Lake Michigan's which had higher ice coverage. I think it's more likely that the inflow from the Niagara River disrupts ice formation at the western end of the lake. The river also carries dissolved minerals from upstream into Lake Ontario which depresses the freezing point of the water. Another consideration is the effect of industrial and municipal usage and return of water at the western edge of the lake which may increase the temperature of the water. One additional factor may be the retention time for Lake Ontario which is only 6 years compared to Lake Michigan's 99 years. This means that the water in Lake Ontario is moving much faster than in Lake Michigan.
More information on ice on the
Great Lakes HERE.