Expect less early ice on Lake Superior, says U.S. scientist

Scientists in Minnesota and Wisconsin say that warm weather this summer has made the water in Lake Superior much warmer than normal — as much as 6 degrees Celsius above average.

This raises some concerns about how much ice will form this year, said Mark Vinson, a station chief with the U.S. Geological Survey at the Lake Superior Biological Station in Ashland, WI.

"It's just going to take that much longer for it to cool off. The lake has a memory of what happened to it the previous season," Vinson said, "So, we'll probably see less ice early on than we'd normally see."

There is also an effect on fish, as plankton and organisms are more affected by temperature change, Vinson said.

There's good news for some fish, who will experience greater growth because of the increased temperatures. It's equally bad for others, as smaller organisms are more responsive to temperatures outside the norm, similar to how an adult can withstand more overall change than an infant could, Vinson said.

The last time temperatures were like this was in 2010 and again in 2012, Vinson said.

"That's what we're kind of anxious to see what's going to happen this next winter," Vinson said.

"Is it the same thing that we saw in 1998? Or, is it kind of like a new regime?"

1998 was the year of El Nino, which also affected North America this past winter. Vinson said that could mean a winter similar to that of 1999.

"So, what we saw after '98 was we saw that every year was a little bit warmer than up until 2014 when we got that really cold year. I mean there were a couple cold years, like 2009, that was a cold year."