From Ocean Navigator #102 November/December 1999 |
Warm eddies are being studied to determine their effect on hurricanes.
Weather scientists at several NOAA facilities in Florida have been studying the effect of warm eddies on hurricanes to determine the extent they intensify major storms. During this past hurricane season, which was still generating storms like Dennis and Floyd at press time in mid-September, scientists at NOAA’s Atlantic Oceanographic and Meteorological Laboratory in Miami and the University of Miami’s Rosenstiel School for Marine and Atmospheric Science were interested in how some storms, after coming in contact with a warm eddy in the Gulf of Mexico, could dramatically increase in strength. Hurricane Opal in 1995, for example, increased from a category two hurricane to category four in just 14 hours. Aircraft deployed ocean sensors into the Gulf in August to study this phenomenon. Sensors measure current direction, velocity, and water temperature to a depth of 3,000 feet. “Major hurricanes (winds stronger than 115 mph) cause 80% of all hurricane-related damage, and rapid intensification causes major hurricanes,” said Dr. Hugh Willoughby, Director of the Hurricane Research Division at AOML in a statement. “What we don’t know are all the factors that can cause rapid intensification. But what we do know is that warm eddies were a factor in some memorable Gulf storms.” Scientists are particularly interested in the deep warm-water eddy formed from the Loop Current. The Loop is a stream of warm Caribbean water that enters the Yucatan Channel, meanders northward almost to the Gulf Coast, and exits into the Straits of Florida after a sharp turn around the Florida Keys, where it is known as the Gulf Stream.