Great Lakes Shrinkage Theory
Higher water temperatures and an increase in wind speeds over Lake Superior appear to be factors in the decline in water level. Water temperatures on Lake Superior have risen twice as fast as air temperatures in the past 25 years.
The same goes for the other Great Lakes, which are inches above record lows. The change in lake temperatures tracks the rise in air temperatures that scientists around the world have documented in the second half of the 20th century, accelerating since 1970. Looking at shoreline temperature data over 100 years and data from buoys in the middle of Lake Superior since 1980, sharp increases in air and water temperature began about 25 years ago. Ice cover on the upper Great Lakes has dropped by half in recent decades.
While scientists might expect that big lakes, such as Superior, would respond more slowly to higher temperatures, it seems Lake Erie, which is smaller and shallower, is the one that has responded more slowly. Similar changes in wind speed and water temperature might be happening on smaller lakes worldwide. The findings come from Jay Austin out of UMD.
November 5, 2007 8:39 AM | Category: Global Warming