It's enough to make your hair stand on end. Literally. By that point, however, William Beasley says, "it's almost always too late.”
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Lightning, those arcs of electrical energy so powerful they leap across miles of sky, are among nature's most amazing and, so far, mysterious displays. Beginning with a buildup of static charge that sometimes can be felt and heard on the ground moments before a strike, a bolt of lightning's main "leader” can reach temperatures five times that of the surface of the sun. The discharge can cause all manner of havoc, from destroying electrical equipment to causing fires and death.
So it's good to learn as much as possible about such things, which is what Beasley and fellow researchers Donald MacGorman and Ted Mansell plan to do. A proposal by Beasley, meteorology professor at the University of Oklahoma, and MacGorman and Mansell, research scientists at the National Severe Storms Laboratory in Norman, won a $1.4 million grant from the National Aeronautics and Space Administration.
The three-year grant will be used to establish the Center for Lightning Advanced Studies and Safety (CLASS) at OU. The center will focus on improving ground-based observations of lightning by adding eight "moveable” monitoring stations to an existing "lightning mapping array” of 11 fixed stations operating in central Oklahoma.
Those stations, which detect lightning locations by triangulating on the radio frequency emissions they produce, currently cover an area about 250 miles in diameter. They can produce three-dimensional profiles of lightning in an area 100 miles in diameter.
The added stations will increase the coverage area and improve the data collection. Researchers will use the improved system to cross-check visual satellite lightning data, gaining what they hope will be new insight into the shapes, behavior and even predictability of lightning.
The grant will also pay for a high-speed digital camera, a leap in technology over the old high-speed, film-based "streak cameras” the Norman researchers have been using — one of which they purchased on eBay. Combined with other data, Beasley said, "we can get from beginning to end and top to bottom the whole sequence of events in a lightning flash.”
Besides producing lots of gee-whiz data and photos of lightning, the data is important for plenty of practical reasons, the researchers said. For one thing, if you know exactly where lightning is, you know where the powerful and dangerous part of a storm is and where it's likely to head.
"If you can get the initial conditions more accurate, then your forecast is going to be more accurate,” MacGorman said. "It puts the thunderstorms in the right place.”
More understanding of lightning might even result in some tweaking of the old "30/30” safety rule of thumb, which states you should seek shelter if you hear thunder within 30 seconds of lightning and stay there until 30 minutes after the last thunder. Shaving even a few minutes can save millions of dollars in refunds, delays and other losses for airlines and other businesses and at public events and sports venues.
"The big problem is the false-alarm rate,” Beasley said. "If they have to stand down because there's lightning ... that's money.”
Confirming and improving satellite visual lightning detection would also be a leap forward. Satellite monitoring means storms can be tracked over oceans and across other remote parts of the world that are not covered by radars or other ground-based systems, MacGorman said.
"It detects storms everywhere,” he said. "Radars have some limitations. They can't look through mountains very well.”
Lightning might even be a "kind of global thermometer,” Beasley said, explaining that increased lightning might mean increased convection, which could be the result of increased temperature. But, MacGorman said, that idea is controversial and would take years of study to confirm.
The researchers also are eager to learn more about sprites — the cloud kind, not the fairy kind. Sprites and elves and jets are some of the names given to mysterious "transient luminous events” — diffuse electrical discharges seen high in the atmosphere in clear air above storm clouds.
"They know they're associated with very big lightning flashes,” MacGorman said of researchers studying the phenomena. "But they can't pin it down.”
Norman researchers recruited a physicist at Southwestern Oklahoma State to help search for sprites using low-light cameras, a project pioneered by a researcher in Colorado, Beasley said. "We'll be looking that way, and he'll be looking this way.”
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•Lightning causes an average of 80 fatalities and 300 injuries each year.
•Lightning occurs in all thunderstorms; lightning strikes the Earth 20 million times each year.
•Most lightning fatalities and injuries occur when people are caught outdoors in the summer months during the afternoon and evening.
•Lightning can occur from cloud-to-cloud, within a cloud, cloud-to-ground, or cloud-to-air. Air near a lightning strike is heated to 50,000 degrees, causing a shock wave and thunder.
Source: National Oceanic and Atmospheric Administration
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