March 24, 2009

Ice On Great Lakes Continues To Shrink

The Great Lake's ice cover has gradually reduced by 30 percent since the 1970s, causing the biggest source of freshwater to become vulnerable to evaporation and poor water levels, say the scientists at the National Oceanic and Atmospheric Administration.

The scientists are worried about how the placid winter weather may influence the environment. However, they are also working to come to terms with the juxtaposition of the situation. The barely freezing weather that may melt the lake ice could make freezing more likely to happen if lake levels fall from evaporation.

Scientists at the Great Lakes Environmental Research Laboratory state that the climate change fights against area weather patterns. Precisely calculating ice cover in a lake system that covers 94,000 square miles is a huge job, they add.

Their research demonstrates that even though the volume of ice cover can change from year to year, generally the ice coverage on the freshwater lakes is retreating, particularly in the deepest parts of Erie, Huron, Michigan, Ontario and Superior.

"The deeper the water, the greater the heat storage from summer, and it freezes later than the shallow areas," research Ray Assel stated to The Plain Dealer. "Now, increase the air temperature and the lake takes in more heat and stores it longer, to the point that many of the midlake areas are freezing over less."

Assel's research shows that ice configuration at nearshore regions has reduced less than in the deepest areas.

Researcher Jia Wang said the loss of lake ice can cause other problems, such as egg loss for fish, wearing away of coastal areas and less winter recreation.

There could be one benefit to the melted ice: shipping might become a possibility in the winter months. Shipping usually halts each year mid-January and reopens in late March.


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