Great Lakes now clear of ice? Hello, summer.

Wednesday, June 11, 2014

For the first time in seven months, the Great Lakes is now free of ice, at least according to the National Oceanic and Atmospheric Administration (NOAA), which officially declared the start of summer in the Great Lakes region Tuesday.

However, the NOAA's announcement is clearly at odds with sightings of huge chunks of ice still floating on the surface of Lake Superior. The summer icebergs were first seen last week by Wisconsin Department of Natural Resources marine warden Amie Egstad, who was conducting commercial net checks when she found the ice floating near Madeline Island, just off the northern coast of Wisconsin.

Egstad's observation confirms a report created by NOAA's Great Lakes Environmental Research Laboratory, which shows that while four the the Great Lakes are now ice-free, Lake Superior still showed 0.5% ice coverage as of Monday, June 9.

Egstad says she was surprised to find a flock of seagulls that have claimed the the 14-foot high ice island as their home. Much of the chunk, Egstad says, is found underwater, but she estimates that it is 40 feet long and 20 feet wide. Egstad believes it will "a bit before the ice is actually gone" due to the low temperature of the water in the area, which is at 34 Fahrenheit.

The rest of the Great Lakes, however, is now devoid of icy chunks due in part to a succession of warm 80 Fahrenheit days and the 2,000 hours spent by the Coast Guard in ice-breaking operations in the winter.

But while residents in the Great Lakes region can finally start looking forward to warmer temperatures in the days ahead, they will most likely not be able to tolerate swimming in the colder temperatures of the Great Lakes. Last winter's colder-than-average temperatures brought more than icebergs that lasted into the summer.

Scientists say that while surface temperatures will rise enough to melt the last of the icy chunks, temperatures below the surface, especially in deeper Lake Superior, will remain in the lower 40s, which is an entire 6 degrees below the water's average temperature during the summer. What this means for Great Lakes residents are higher water levels and more fog.

"It's going to be the summer of fog," says Peter Blanken of the University of Colorado. "The water will stay really cold, but summer air tends to be warm and humid. And any time you get that combination, you're going to have condensation and fog - basically evaporation in reverse."

Colder temperatures will also make it more difficult for the water to evaporate, which could mean a good thing since less evaporation means more water. Great Lakes Integrated Sciences + Assessments Center climatologist John Lenters predicts Lake Superior, which experienced low water levels last year, could gain as much as 10 inches in water level due to the last winter's extreme temperatures.

Source: http://www.techtimes.com/articles/8307/20140611/great-lakes-now-clear-of-ice-hello-summer.htm