Fast Eddy and friends stoke hurricanes

CAMBRIDGE, Mass., Sept. 27 (UPI) -- Scientists believe they have discovered why Hurricane Katrina became so strong and why Hurricane Rita weakened before landfall.

The answer, according to Kerry Emanuel of the Massachusetts Institute of Technology, is an oceanographic phenomenon called the loop current.

Although the loop current was identified long ago, it's been little more than a curiosity, the New York Times reported. But now, since its role in energizing storms has been discovered, it has become a focal point for hurricane forecasters.

Emanuel said the current carries warm water from the Caribbean Sea around Cuba and into the gulf. It then usually flows toward Louisiana and finally exits between Florida and Cuba, going on to form what's known as the Gulf Stream.

The loop current or one of its eddies can be 79 degrees as deep as 300 feet -- giving hurricanes a nearly inexhaustible supply of warm water they need in order to intensify.

Oceanographers have started naming the circular currents that develop, the Times said. For example, the one that nurtured Hurricane Juan was Fast Eddy, the Times noted. Other eddies have been called Murphy and Nelson.