When Sam Perri first learned that Microsoft founder Bill Gates and a group of co-inventors had filed patents proposing to slow hurricanes by using barges to pump cold water from the bottom of the ocean to lower surface temperatures, he thought it was a great idea.

And why not? He had proposed the same thing four years earlier.

The Gates group filed a total of five applications with the U.S. Patent and Trade Office seeking legal rights to the idea, which is based on the fact that hurricanes draw strength from warm waters on the ocean's surface. The filings were disclosed in July.

The patents outline a method for cooling surface temperatures by having a fleet of barges move in advance of the hurricane's predicted path, pumping colder water from depths of 500 or more feet to the surface.

The plan holds that by cooling surface temperatures by even four degrees over a wide enough area, the barges could theoretically weaken, divert or even disperse the gathering storm.

The patents were filed by a group including Gates, climate scientist Ken Caldeira of the Carnegie Institution of Washington, Jeffrey Bowers, Alistair Chan, Roderick Hyde, Muriel Ishikawa, Jordin Kare, John Latham, Nathan Myhrvold, Stephen Salter, Clarence Tegreene and Lowell Wood Jr.

A blog posted on the Web site for Myhrvold's Intellectual Ventures Lab, which is developing the hurricane-suppression idea, states: "We absolutely believe that we should investigate our options should the environmental change cause severe disruption. This type of technology is not something humankind would try as a 'Plan A' or 'Plan B.' These inventions are a 'Plan C' where humans decide that we have exhausted all of our behavior changing and alternative energy options and need to rely on mitigation technologies. If our planet is in this severe situation, then our belief is that we should not be starting from scratch at investigating mitigation options."

The method in the patents is nearly identical to one proffered by Perri in 2005.

"When I first heard about it, I thought, 'Hey, I'm vindicated!'" said Perri, a retired University of Hawai'i biology professor. "I recognized the connection to my idea right away. I guess it wasn't such a bizarre, silly idea if someone of Gates' stature is willing to invest billions of dollars in it."

Perri, 80, said he first came up with the idea while watching news accounts of hurricanes. Acknowledging that he did not have a background in meteorology, he shared his ideas in a letter to the University of Hawai'i meteorology department that year asking for feedback but did not receive a reply.

Perri later sent the idea to a friend in Florida, who forwarded it to Florida Gov. Charlie Crist.

He said he believes someone of Crist's staff shared the unattributed document with "people around Gates."

Perri said he is not interested in "going up against Gates' army of lawyers" to seek recognition or compensation. Rather, he said, he is gratified that the idea is being taken seriously, and that it could one day help to minimize the damage caused by hurricanes.

"I envision a fleet of barges in every major port in the world," Perri said. "It shouldn't just be one location looking out for itself. It should protect everybody — in Hawaii, Florida, Mexico, Indonesia, all around the world."

In fact, Perri is one of several theorists and inventors who lay claim to the idea.

A Roanoke-based innovation company called The Egg Factory filed a similar patent application in 2000, intending to use unmanned submarines to divert cold water from deep sea to the surface.

A company called Atmocean, which manufactures pumps used to draw nutrient-rich water from the deep sea to replenish surface waters, has also previously proposed the use of their pumps in hurricane suppression. Atmocean is mentioned in the Gates group application.

Kevin Hamilton, a UH meteorology professor and interim director of the International Pacific Research Center, said the idea of cooling surface temperatures to combat hurricanes has been around since at least the early 1970s, when he was a graduate student.

Early iterations of the idea included proposals to use giant propellers to churn the waters, he said.

Hamilton recalls seeing Perri's letter, concluding at the time that Perri "didn't seem to realize it was an old idea."

Hamilton said that while the basic physical principal of the idea is sound, proving it a worthwhile enterprise is problematic.

"If you only make the water a little colder, it won't weaken the hurricane enough to make that much of a difference," he said. "Even as an experiment, you have to go the whole way, and that's a pretty big investment."

Hamilton also said that measuring the cost benefits of such intervention can be difficult, given the unpredictability of hurricanes. Legal, philosophical and ethical issues — "What happens if you divert the hurricane away from Florida and it hits Cuba?" he asked — could also complicate matters.