Lake Superior's ice will change upcoming seasons

By KBJR News 1

February 5, 2014 Updated Feb 6, 2014 at 12:09 PM CDT

Duluth, MN (NNCNOW.com) - We all know it has been a cold winter resulting in more ice on Lake Superior than we've seen in several years.

Our cold winter has done the obvious, leading to extended ice coverage on Lake Superior. It was once thought with more lake ice that there's less evaporation but Doctor John Lenters, of Limno Tech, says it doesn't help as much as once thought. That's because the peak evaporation season is late fall into early winter, when the lake is still warm.

He says, "We have a lot of evaporation prior to that, that leads to cooling but then causes the lake to freeze. Later in the year, of course, we have higher ice cover and that can cap evaporation, but that doesn't happen until March or April when we don't have conditions right for evaporation in the 1st place."

The conditions aren't right late in the season because that's when the water is coldest and the molecules within the water don't separate as easily. With the current low levels on Lake Superior that sounds like good news Lenters says, "In the long term it should be a positive, but we don't have an answer for that yet."

Imagine the lake like a glass of water with ice, the water stays cool even after the ice melts. So what else does all this lake ice mean for our upcoming spring and summer seasons?"

Dr. Jay Austin of the Large Lakes Observatory at UMD says, "The Chamber of Commerce is not going to like to hear this, but it will be a really poor year for swimming unless you like it really, really cold."

Austin says warm water won't start forming on the lake surface until late into the Summer around August. "Summers start much later and are much much, more cooler than in years that we have lots of ice."

And this year we have a lot of ice! Austin says, "This is the strongest ice cover we've had since good areal coverage records have been kept since the 70s or so."

Dr. Austin says we usually see the most lake ice in early to mid March.
He also stresses that the ice is never thick or stable enough to snowmobile across Lake Superior.

So strap in! It looks like this summer the air conditioned city's air conditioning will be on full blast!

Adam Clark
Chief Meteorologist
aclark@kbjr.com

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