Hurricanes Rita and Katrina exploded into major category five hurricanes while over the Gulf of Mexico. However, they both weakened before striking the gulf coast.

The University of Colorado at Boulder has done research showing that a phenomenon known as the "Loop Current" was involved in the intensification.

The Loop Current is a band of water which flows up into the Gulf of Mexico, and is composed of very warm and deep water. Robert Leben, a professor with the university's Colorado Center for Astrodynamics Research (CCAR), says that satellite images show the Loop Current contains water which is 20 to 30 inches higher than surrounding water.

A hurricane's fuel is warm ocean water. This Loop Current provided the extra energy for both hurricanes to intensity further. As the storms departed the region of the Loop Current, the storms weakened before making landfall.

George Born, a colleague of Leben and the director of CCAR, said that the Loop Current normally doesn't move this far into the Gulf of Mexico. Had the Loop Current been in a more typical position, the hurricanes would not have strengthened as much.

Below are images showing plots of the Loop Current, along with both hurricane paths and associated wind speeds. You can see how the maximum speeds occur over the Loop Current, and then the speeds decrease after moving past the region of the current.

More information can be found at http://www.colorado.edu/news/releases/2005/358.html







































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