Lake Water Warming Faster Than Climate
Lake Superior is warming faster than the world climate, University of Minnesota Duluth researchers report.
Since 1979, the lake’s summer surface
temperatures have risen about 4.5 degrees Fahrenheit while average air
temperatures have gone up about 2.7 degrees. The difference appears to
be tied to winter ice.
“Winter ice cover is the primary indicator of
how warm the lake will be the following summer … if you have a lot of
ice, but a warm summer, the lake will still be cool that year,” says
Jay Austin, assistant professor with the Large Lakes Observatory and
the UMD Department of Physics, who co-authored the study with Steve
Colman, director of the Large Lakes Observatory and a UMD geology
professor. Hotter summers also affect all the lakes.
This study was initiated by review of the daily
temperatures taken since 1906 at the hydroelectric plant on the St.
Marys River. A summary of the study and how it was done is at
www.d.umn.edu/~jaustin/ICE.html.
Lake Notes
 A
Water Resources Development Act, passed 394-25 in the U.S. House,
authorizes many Great Lakes projects, such as $341 million for a larger
modern lock at Sault Ste. Marie, Michigan, the go ahead for additional
dredging and funds for study the cause of unusual structure corrosion
in the Duluth-Superior harbor. Minnesota Rep. James Oberstar was the
bill’s primary author.
Lake
Superior’s water level was expected to be at 599.9 feet on April 20,
which is 17 inches below the long-term average for April. It was
projected to rise 3 inches by May 20.
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