Hurricane study brings wealth of information

Airborne Rain Mapping Radar image shows a vertical slice through the northern eye wall of Hurricane Bonnie on Aug. 24. The most intense precipitation, yellow and white at left, is the eye wall

January 21, 1999
Web posted at: 12:15 PM EST

By Environmental News Network staff

(ENN) -- A multi-agency study of hurricanes this past summer has given federal and university scientists a wealth of data to study this winter as they fine tune their ability to predict hurricane landfall and intensity.

The study, dubbed the Convection and Moisture Experiment, sent a series of high-tech-instrument-laden aircraft, that flew at altitudes two to three times higher than conventional research aircraft, into the clouds of hurricanes where satellite cameras cannot penetrate.

"The wealth of information collected ... will lead to better hurricane forecast capabilities in the future," said Robbie Hood of NASA's Marshall Space Flight Center.

The researchers, who included participants from the National Aeronautics and Space Administration, the National Oceanographic and Atmospheric Administration, military institutions, university personnel and weather professionals, are hoping to hone their ability to gauge the strength of a hurricane and how it will change when it makes landfall.

The analysis of the hurricane data will take several months to complete, but Hood is excited by the preliminary results and observations that have been made by the various researchers so far.

The experiment was carried out between Aug. 12 and Sept. 23, 1998. During that time the researchers lucked out, as four major hurricanes -- Bonnie, Danielle, Earl and Georges -- and one tropical storm -- Hermine -- developed in the Atlantic Ocean.

"Each of the hurricanes we sampled was different, so we think that was a great accomplishment to get so much different data," said Hood.

One of the things the researchers have learned is that the inflow and outflow wind patterns are much more complicated than expected, said Hood. The direction and strength of the wind patterns are a measure of the energy flow within the hurricane and may help predict its future.

Gerry Heymsfield of NASA's Goddard Space Flight Center said that data showing how mountains in the interior of the Dominican Republic significantly enhanced rainfall will keep him busy for quite some time.

"We got a glimpse of an example of the impact of the storms with a mountainous island and the subsequent rain which eventually caused significant loss of life. Understanding this very complicated interaction between Hurricane Georges and the mountains will keep us busy for a while."

Another surprise came when Hurricane Bonnie "winked" at the research team, said Hood. Bonnie's eye changed shape during successive passes by a DC-8 airplane on Aug. 24.

"I had no idea that the position or structure of the eye would change that fast," said Hood. "It was pulsating; it was undulating."

Later this year, the researchers will pool their data and analysis and determine precisely how the Convection and Moisture Experiment has aided their understanding of hurricanes.

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