1 of 2
Lake Superior: Feb. 6, 2014
The mostly-frozen Big Lake, as seen from space on Feb. 6 by NASA's Terra MODIS satellite. Ice concentration was 91.2 percent. A high-resolution version is available.
2 of 2
Ice Cover: Feb. 7, 2014Ice cover on Lake Superior topped 90 percent in early February, the most ice on the Lake since 2009 and far surpassing last winter's high of 40.5 percent.
Ice cover on Lake Superior reached 92.4 percent this morning, a visual reminder of what we can all feel: It's been a brutal winter, at least compared to recent years.
In Duluth, the U.S. National Weather Service says this January was the coldest since 1994. Though the region didn't set many low-temperature records last month, the long streaks of below-average days allowed ice to rapidly form.
And there's likely more coming. The ice cover usually peaks in early March, when the Lake is its coldest. We last saw 90 percent in 2009, when the ice topped out at 93.6, but this year the Lake hit 90 percent nearly a month earlier.
Lake Superior hasn't completely frozen over since 1996.
The ice will mean less lake-effect snow for the region. Lake effect occurs when cold air passes over the warmer water, plucks out moisture and returns it to the earth as snow. The ice prevents that required evaporation.
The Keweenaw Peninsula has already seen 230 inches of snow this winter, with nearly four feet currently on the ground. That's well above average, says Pasty.com. In Marquette, LSM contributor Shawn Malone tweeted: "waist high in the woods, over the mailboxes, and drifts over 6ft fence in ONLY January is enough! what will March bring??"
As Lisa Borre reported for National Geographic's NewsWatch, the ice also helps boost lake levels, though not exactly in the ways many long believed. Ice does cap evaporation, but almost all of the resulting lake-effect snow returns to the Lake in the spring anyway:
What’s more important is that ice leaves the lake cooler the following summer and delays the next year’s “evaporation season,” according to the study.