By Irene Klotz
CAPE CANAVERAL, Florida (Reuters) - NASA is using of a pair of decommissioned military drones to study how tropical storms develop over the Atlantic Ocean.
The campaign, known as the Hurricane and Severe Storm Sentinel, or HS3, began last year with one Global Hawk unmanned aircraft outfitted with instruments to probe the environment around a developing storm.
With two planes available for the 2013 Atlantic hurricane season, scientists are focusing on the interior of storms as well. The project could improve storm prediction and forecast models by shedding light on how tropical cyclones can rapidly intensify.
"The second aircraft will measure eyewall and rainband winds, and precipitation, something we didn't get to do last year," project lead scientist Scott Braun, a meteorologist with the U.S. space agency's Goddard Space Flight Center in Greenbelt, Maryland, said in a NASA interview.
"Just as we did in 2012, the first aircraft will examine the large-scale environment that tropical storms form in and move through, and how that environment affects the inner workings of the storms," he said.
The NASA Global Hawks were built for the U.S. Air Force by Northrop Grumman Corp, part of a fleet used for surveillance missions over Afghanistan, Iraq and Libya.
Global Hawks, which first flew in 1998, also have supported disaster relief efforts in Haiti and Japan. NASA first used the planes for scientific research in April 2010.
Global Hawks are particularly suited for atmospheric studies since they can reach altitudes greater than 60,000 feet, about twice as high as commercial airplanes, and can stay airborne for up to about 28 hours.
For its hurricane research program, NASA is remotely flying its Global Hawks from the Wallops Flight Facility on Wallops Island, Virginia. Flights began in late August and are scheduled to run through September 23. The Atlantic hurricane season runs from June 1 to November 30 and typically peaks in early to mid-September.
The next flight from Wallops is scheduled to leave no earlier than Friday, NASA spokesman Keith Koehler said.
The project is expected to run through next year.
(Editing by Tom Brown and Stacey Joyce)