Oceanographers at the University of Rhode Island have analyzed long-term data from several anemometers（风速计） in southern New England and found that average wind speeds have declined by about 15 percent at inland sites while speeds have remained steady at an offshore site. Kelly Knorr, a graduate student at the URI Graduate School of Oceanography, and Professor John Merrill reported the results of their research December 5 at the fall meeting of the American Geophysical Union in San Francisco.

The researchers found that average wind speeds at T.F. Green Airport in Warwick, R.I., declined from about 9 knots to 7.7 knots from 1975 to 2011 and from about 8.2 knots to 7 knots at New Bedford Regional Airport in Massachusetts from 1973 to 2011. A 25-year record of wind speeds at a buoy（浮标） at the mouth of Buzzards Bay, Mass., shows that wind speeds there remained steady at about 15 knots during the period.

Knorr and Merrill suggest several reasons for the decline in wind speeds at inland locations, including changing weather patterns and urbanization.

"If the anemometer height is at about the same level but everything else is growing up around it, like buildings and forests, that would create surface roughness or drag that could decrease wind speeds," said Knorr, an ensign（海军少尉） in the U.S. Navy assigned to URI to earn a graduate degree.

The scientists say that climate change may also be a factor. "Southern New England has typically had a long period of frequent winter storms, but with climate change, that pattern of winter weather is shifting to the north, meaning we may be in that pattern less often," said Merrill. "If those mid-latitude storms aren't here as often, average wind speeds will decrease."

Knorr and Merrill say that data from other sites should be analyzed to confirm the trend they found.

"The Department of Energy wants the U.S. to have 20 percent of its electricity generated from wind power by 2030, but if this trend of declining wind speeds is widespread across the country, then that could have a significant effect on the future of wind energy here," said Knorr.