Five U.S. Patent and Trade Office patent applications, made public on July 9, propose slowing hurricanes by pumping cold, deep-ocean water in their paths from barges. If issued, the patents offer 18 years of legal rights to the idea for Gates and co-inventors, including climate scientist Ken Caldeira of the Carnegie Institution of Washington.

Hurricanes, most famously demonstrated by the deadly intensification of Hurricane Katrina before its landfall in 2005, draw strength from warm waters on the ocean's surface. The patents describe a system for strategically placing turbine-equipped barges in the path of storms to chill sea surfaces with cold water pumped from the depths.

First requested by Gates and colleagues last year, the patents describe methods "not limited to atmospheric management, weather management, hurricane suppression, hurricane prevention, hurricane intensity modulation, hurricane deflection" to manage storms.

Given the scope of the applications, "I suspect these will have a lengthy stay in the examiner's office. They are talking about some interesting issues here," says patent expert Gene Quinn of IPWatchdog.com.

The Bill & Melinda Gates Foundation and Caldeira declined to comment on the patents.

"The bottom line here is that if enough pumps are deployed, it is reasonable to expect some diminution of hurricane power," says hurricane expert Kerry Emanuel of the Massachusetts Institute of Technology. He is not part of the patent effort. Cutting sea surface temperature by 4.5 degrees under the eye of a hurricane would actually kill a storm, he adds. "This would have to be done on a massive scale, but is still probably within the realm of feasibility."

Says climate scientist Michael Mann of Pennsylvania State University in State College: "Needless to say, there is a whole lot of skepticism about this among tropical meteorologists. But it's not so ridiculous that I would actually dismiss it out of hand. There is certainly an important role of upper ocean mixing on tropical cyclone behavior."

Ocean water quickly grows colder with depth, reaching temperatures of 28 to 37 degrees (salty ocean water doesn't freeze at 32 degrees) about 500 feet down. The patents envision sail-maneuvered barges, with conduits 500 feet long, pumping warm water down to the depths and bringing cold water up. The average depth of the Gulf of Mexico is 5,300 feet.

"By cooling a region in the path of a hurricane (over 60 square miles), models suggest we could knock a half-a-category in wind speed out," says Philip Kithil of Atmocean in Santa Fe, an ocean-pumping firm mentioned in Gates' applications. "All the models indicate the path of the storm would be unaffected."

In the average year, six hurricanes develop in the Atlantic Ocean, Caribbean or Gulf of Mexico in a season that officially extends from June 1 to Nov. 30. Over the past century, the annual cost of hurricanes to the USA has averaged about $10 billion, according to a 2008 Natural Hazards Review study. In 2005, Hurricane Katrina killed at least 1,800 people and caused at least $81 billion in damage.

"From a scientific and political standpoint, (the Gates plan) looks fanciful," Quinn says. "But the physics is real and like a lot of things, the question is whether the damage you prevent is worth the money you would spend to develop something so massive."

[Source: www.usatoday.com]