Sarasota Herald Tribune (Florida)
WEATHER: Aim of aircraft is to gather data to solve mysteries of the storms
An eight-pound drone that can sprout wings and nose into a hurricane’s eyewall on command could revolutionize hurricane forecasts.
The tiny aircraft, dubbed Gale, will be the first remote-controlled instrument capable of collecting continuous data – for at least an hour – from a storm’s dangerous lower eyewall, where the wind interacts with the surface of the sea.
Scientists say that lower part of a hurricane probably holds the mystery behind why some storms suddenly intensify and others unexpectedly weaken, such as the recent Hurricane Irene.
The problem confounds forecasters, who have made a 50 percent improvement in predicting where a storm will go, but have been stuck in a rut on intensity projections.
Scientists plan to drop Gale from a Hurricane Hunter aircraft for the first time in a test run soon. The Hurricane Hunter will leave from MacDill Air Force base in Tampa and drop Gale over Avon Park. The drone is not ready to face Tropical Depression Ophelia near Puerto Rico.
But when Gale is prepared for a hurricane, advancements in storm intensity forecasts are likely to be substantial, said Joseph Cione, lead scientist on the project for the National Oceanic and Atmospheric Administration.
“It’s not something that’s been done before. It’s exciting, and it’s an area where there’s a big need,” Cione said.
The bottom of a hurricane, especially the eyewall, is too turbulent for even the bravest of hurricane hunter pilots.
Instead of flying into that danger zone, scientists drop devices, called dropsondes, into the storm from above.
Dropsondes can capture data from the eyewall, but not in enough detail for scientists to get a clear picture of what happens there. Also, they go wherever the hurricane takes them and stay in the storm only for about five to seven minutes.
Gale will collect similar atmospheric data but will go where scientists steer it for at least an hour, possibly longer.
Hurricanes get their energy from warm seas, but scientists do not know exactly how they intensify.
“We don’t have the data to understand exactly how the energy is extracted from the ocean,” Cione said.
Once scientists better grasp how ocean heat fuels hurricanes, they can modify the computer programs that make intensity forecasts. After new programs are created, the data from Gale can then be used in those forecasts.
Major advances could be seen in five to 10 years, Cione estimated.
Gale also will help more immediately with day-to-day predictions, by giving hurricane forecasters a more accurate read on a storm’s intensity.
While Cione is working on the hurricane science aspects of the Gale project, his collaborator, Massood Towhidnejad, is working on the engineering.
Gale has spent plenty of time in wind tunnels at Embry-Riddle Aeronautical University, where Towhidnejad is a professor. The device needs to undergo more testing before navigating an actual tropical storm or hurricane.
The next experiment, called a “clear air flight,” is meant to make sure everything on the Gale aircraft works before going into a hurricane.
Gale can survive 120 mph winds in the wind tunnel, but no simulator can reproduce a hurricane’s violent wind shifts.
Experiments with hurricanes should begin next year.
“It will probably be more of a trial and error,” Towhidnejad said.