The National Science Foundation is refurbishing a retired A-10 warplane, equipping it with scientific instruments to study severe-weather systems. This Thunderbolt will soon be flying into thunderstorms.
By Mara Grunbaum
November 18, 2011 2:30 PM
The U.S. military's veteran A-10 Thunderbolt II is built for battle: a titanium-armored cockpit protects its pilot from explosive projectile hits, and it can carry weapons like a 30-mm nose-mounted cannon to take out enemy tanks. Now the National Science Foundation (NSF) plans to arm a retired Thunderbolt not with bombs, but with scientific instruments, and use it to study the inside of violent thunderstorms—where winds, hail, and lightning would take down lesser planes.
The NSF recently awarded a $10.9 million grant to the Naval Postgraduate School in Monterey, Calif., a to refurbish a retired Thunderbolt for use as a storm-penetrating research plane, the journal Science reported this week. Stripped of weapons and outfitted with instruments and sensors, the extra-tough A-10 will let researchers study massive, energetic storms from the inside, increasing their understanding of how these damaging storms form and evolve, and helping meteorologists predict when and where they will strike.
"Conventional research aircraft avoid these severe storms, so they're basically outside looking in," meteorologist and veteran storm-chaser Joshua Wurman of the Center for Severe Weather Research in Boulder, Colo, tells PM. "We want to study the worst weather, but we're trying to keep the [plane] outside the worst weather. With the A-10, we don't have that limitation."
A couple of the Thunderbolt's targets will be supercell thunderstorms, which birth tornadoes, and mesoscale convective systems, giant storm clusters that can produce thunder and lightning, pounding hail, and damaging winds. Ground-based radar systems can track wind and precipitation in these systems fairly well from a distance. But to understand how temperature and humidity contribute to tornado formation, for example, researchers need to get at the heart of the storm.
The A-10 replaces a T-28, a small, single-propeller armored plane that flew into storms for 35 years before it was grounded in 2005. The Thunderbolt (also nicknamed Warthog, after its toughness and looks) can carry more than five times as much weight as the T-28, meaning it could bring heavier instruments such as radar and other remote-sensing equipment into the air. The A-10 has a far greater range, too, which will let it venture out to study thunderstorms over the ocean and the mechanics of hurricane formation. And where the T-28 had a maximum altitude of 23,000 feet, the Thunderbolt can reach nearly 40,000 feet: high enough to get above some storms, or to study the upper reaches of severe storms that stretch as high as 50,000 feet above sea level. "A lot of the important physics is happening throughout the depth of these storms," Wurman says, "so the higher we can go, the more comprehensive the measurements we can take."
The A-10 is rugged, but not invincible. It couldn't fly directly into a tornado, for example, and very high g-forces or hailstones much bigger than golf balls would probably put the plane and its pilot at risk. Scientists on the ground plan to use satellite communications to monitor the plane and direct it toward the most interesting parts of the storm, but ultimately, it will be up to the pilot to decide whether it's safe to proceed. "Doing frontier science does involve risks, but there are limits," said Brad Smull, a program director in NSF's Division of Atmospheric & Geospace Sciences, in a live chat hosted by Science this week.
The ready-to-be-refurbished Thunderbolt recently arrived at the Naval Postgraduate School's Center for Interdisciplinary Remotely Piloted Aircraft Studies, which operates several other aircraft for scientific research. The mechanics there will modify it for NSF's purposes. But since the A-10 is already hardened for wartime use, Smull said, the mechanics won't have to do too many structural modifications to make the plane stand up to intense storms (though they will remove the cannon and tweak the hardpoints that used to hold bombs to make room for scientific instruments). And because the A-10 originally was built for ground attacks, the plane can fly at slower speeds, which means it can spend a longer time inside storms recording quality data.
The NSF plans to have the plane ready by 2013, at which point scientists will submit proposals for how to use it. According to Sonia Lasher-Trapp, a meteorologist at Purdue University, researchers are already talking about commissioning the Thunderbolt to study electrical activity and lightning production, hail formation, and how thunderstorms over the ocean differ from those over land. Data the plane collects will also help refine computer models and algorithms for predicting storms based on radar and satellite observations.
And, surely, scientists will dream up entirely new uses for the Thunderbolt once it's available, Wurman says. "Once somebody has an airplane, scientists come up with all sorts of things that they want to measure."
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