• E-mail
• Print
• Comment
• Font Size
• Digg
• del.icio.us
• Discuss article

Study: Hurricane Severity Not Determined By Water Temperature

Posted on: Friday, 12 May 2006, 12:00 CDT

By Fred Carroll

Higher sea surface temperatures power tropical storms, but researchers at the University of Virginia dispute how much those temperatures influence a hurricane's severity, and downplay the relevance of global warming on 10 years of busy storm seasons.

"There is a threshold between the warmth of the water and a hurricane's severity," said climatologist Patrick Michaels.

Michaels said global warming might broaden the range of powerful Atlantic hurricanes several decades from now if energy use doesn't change, but he linked current hurricane activity mostly to natural changes in the tropical environment.

Michaels was the lead author of a study that appears in this week's edition of the journal Geophysical Research Letters. He is director of the Virginia Climatology Office and former president of the American Association of State Climatologists. He is also a senior fellow at the Cato Institute, a libertarian think tank in Washington, D.C.

The 2006 Atlantic hurricane season begins June 1 and follows the worst season ever recorded. Two hurricanes skirted by Hampton Roads in 2005.

Michaels' study marked the latest salvo in a contentious public debate among scientists regarding the relationship between global warming and hurricanes.

Some leading scientists contend that global climate change - caused largely by manmade pollution - has spurred more intense hurricanes since 1995 because ocean waters have warmed by 1 degree.

"You can't blame one storm on global warming. You can't blame one period on global warming," Judith Curry, a Georgia Tech scientist, told the Daily Press when she spoke at NASA Langley Research Center in April.

"But when you look at this elevated period - the decade since 1995 - of elevated storm frequency and intensity in the Northern Atlantic, then we've got something we can pin a little bit on global warming."

Other experts disagree.

In their recently released study, Michaels and his colleagues examined water temperatures along individual storm paths to conclude that temperatures above 83 degrees turn a weak tropical storm into a major hurricane.

But once above that threshold, Michaels said, other environmental factors - such as atmospheric temperature and wind speed and direction - account for about half of the increase in strong hurricanes over the past 25 years.

"In the future we may expect to see more major hurricanes," Michaels said, "but we don't expect the ones that do form to be any stronger than the ones that we have seen in the past."

Source: Daily Press

More News in this Category