Wednesday, June 10, 2009

Not so windy: Research suggests winds dying down

FILE -- In a Dec. 30, 2008 file photo two wind turbines stand ...The wind, a favorite power source of the green energy movement, seems to be dying down across the United States. And the cause, ironically, may be global warming — the very problem wind power seeks to address.

The idea that winds may be slowing is still a speculative one, and scientists disagree whether that is happening. But a first-of-its-kind study suggests that average and peak wind speeds have been noticeably slowing since 1973, especially in the Midwest and the East.

"It's a very large effect," said study co-author Eugene Takle, a professor of atmospheric science at Iowa State University. In some places in the Midwest, the trend shows a 10 percent drop or more over a decade. That adds up when the average wind speed in the region is about 10 to 12 miles per hour.

There's been a jump in the number of low or no wind days in the Midwest, said the study's lead author, Sara Pryor, an atmospheric scientist at Indiana University.

Wind measurements plotted out on U.S. maps by Pryor show wind speeds falling mostly along and east of the Mississippi River. Some areas that are banking on wind power, such as west Texas and parts of the Northern Plains, do not show winds slowing nearly as much. Yet, states such as Ohio, Indiana, Michigan, Illinois, Kansas, Virginia, Louisiana, Georgia, northern Maine and western Montana show some of the biggest drop in wind speeds.

"The stations bordering the Great Lakes do seem to have experienced the greatest changes," Pryor said Tuesday. That's probably because there's less ice on the lakes and wind speeds faster across ice than it does over water, she said.

Still, the study, which will be published in August in the peer-reviewed Journal of Geophysical Research, is preliminary. There are enough questions that even the authors say it's too early to know if this is a real trend or not. But it raises a new side effect of global warming that hasn't been looked into before.

via Not so windy: Research suggests winds dying down - Yahoo! News.

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