Einstein Science Reporting for Kids
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14-Feb-2005

Contact: Anne Stark
stark8@llnl.gov
925 422-9799
DOE/Lawrence Livermore National Laboratory

Lightning is a flash point for collaboration



Livermore scientists are working with the university of Florida, where researchers create rocket-triggered lightning to study its effects.
Click here for a high resolution photograph.

The sight of lightning makes some people run for cover. But for Charles Brown and Todd Clancy, lightning makes their hearts pump.

Brown and Clancy, along with Mike Ong of Livermore's Defense Sciences Engineering Division (DSED), are working with University of Florida researchers to test a new lightning measurement system.

"The idea is to understand the phenomena behind these measurements," Brown said.

Lightning occurs when rapidly rising air in a thunderstorm interacts with rapidly falling air to create separate positively and negatively charged areas within a cloud. When the downward negative charges meet with the upward positive charges, a continuous path between the cloud and the ground is formed where the charge is dumped, creating sparks, or lightning).

Lightning is now measured by its electrical current over time. The newer measurements, conducted by British researchers David Newton and Malcolm Jones, use a system that calculates peak current flowing through a conductor.

One year ago, Clancy and Brown began conducting safety measurements at Livermore's Site 300 near Tracy, Calif., on buildings that store high explosives to assure that the explosives, buildings and personnel would be safe in a lightning storm.

"In every facility that houses high explosives we were doing the number crunching to figure out what would happen if it got struck by lightning," Clancy said.




Click here for a high resolution photograph.

Buildings made of concrete reinforced with metal rebar are generally safe from a lightning strike, because the charged particles would travel evenly through the rebar to the ground. Brown and Clancy said most of the buildings tested at Site 300 are made of concrete and rebar, so their job was to determine a safe distance for workers to stay away from the walls during a lightning storm.

Certifying the Site 300 buildings as safe from a lightning strike will save the Laboratory close to $250,000 a year, Clancy said.

Though the Site 300 project is nearly complete, Brown, Clancy and Ong continue to look into new ways to protect Lab buildings from the punch of thunderstorms.

Because lightning strikes are unpredictable, Brown began working with scientists at the International Center for Lightning Research and Testing at Camp Blanding, Fla., where they can test the measurement system on man-made lightning. At the Florida site, lightning is triggered by shooting a rocket with a trailing grounded wire (like a kite tail) at an overhead thundercloud. These experiments can be routinely performed and the resulting lightning studied.

Florida scientists have succeeded in triggering lightning during each thunderstorm season for the past 11 summers.

Though most people stay away from lightning temperatures can exceed 50,000 degrees Fahrenheit triggering lightning with the rocket and wire technique allows researchers to capture lightning to measure its currents.

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Founded in 1952, Lawrence Livermore National Laboratory has a mission to ensure national security and apply science and technology to the important issues of our time. Lawrence Livermore National Laboratory is managed by the University of California for the U.S. Department of Energy's National Nuclear Security Administration.