| Radio programs for the week of 3 July 2000 (fe00703 - fe00707) | For more information: | ||
Summer Lightning Ahead I'm Kevin Pierce with the Florida Environment. As summer weather patterns begin to take hold, we are reminded that Florida is the lightning capital of the United States. Listen to Martin Uman who heads up Florida's Lightning Research Laboratory (Martin A. Uman, Ph. D., professor and chairman of Department of Electrical and Computer Engineering, University of Florida, Lightning Research Laboratory) ... "Florida has more lightning than any other state in the United States. In an area from Tampa to Orlando, down the West Coast, there can be as many as 50 lightnings per square mile per year." Maybe you've heard Florida referred to as lightning capital of the world? Not true. Because Florida's summer doesn't last all year... "There are other places around the world that have more lightning than we do -- for example, Tampa has lightning about 90 days a year, which is basically almost every day in the summer -- some parts of the world that are tropical have lightning all year round. It's always summer." Even though Florida storms aren't as lightning-filled as those in the Midwest, we still see more strikes per year than anywhere in the nation... "Most of our storms are air mass storms, convective storms. They're small and localized and produce the same kind of lightning but maybe only 50 to 100 lightnings per storm, and there may be lots of storms piled up. But it's not as violent a storm situation as you find in other parts of the United States." For more information, visit floridaenvironment.com. With help from its Environmental Studies Program, we're produced at the Whitaker Center at Florida Gulf Coast University and funded by the Southwest Florida Council for Environment Education. |
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 fe00704Why so much lightning? I'm Kevin Pierce with the Florida Environment. As another summer is about to stand proof for Florida's claim as lightning capital of the U.S., you might wonder why there's so much lightning here. It's a magic combination, with three primary ingredients (Martin A. Uman, Ph. D., professor and chairman of Department of Electrical and Computer Engineering, University of Florida, Lightning Research Laboratory)... "Florida is hot and wet and that's the starting point. The other ingredient is sea breezes." Martin Uman works with electrical engineering at the state's Lightning Research Laboratory... "The breezes blow in off the Atlantic and the Gulf and when they blow in to the hotter air inland they undercut it and it rises, forming thunderstorms." Formation of those thunderstorms is amplified by Florida's atmosphere... "What we've got is hot, wet air which normally rises to form convective thunderstorms. And we have an atmosphere that allows the clouds to rise, which means the temperature decreases in the proper amount as you go up in the proper way. And we have this sea breeze which helps the whole thing get going." When it comes to lightning, other coastal areas just don't have what it takes... "If you go to California and along the coast there, it's too cold , the air doesn't have much moisture in it and they don't have the right temperature gradients and atmosphere and it's a different situation." For more information, visit floridaenvironment.com. With help from its Environmental Studies Program, we're produced at the Whitaker Center at Florida Gulf Coast University and funded by the Southwest Florida Council for Environment Education. |
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fe00705 Feeling lightning's power I'm Kevin Pierce with the Florida Environment. While Florida the nation's lightning capital with more strikes per year than anywhere else in the U.S., lightning takes a special spot in Florida. Especially in the eyes of insurance companies (Martin A. Uman, Ph. D., professor and chairman of Department of Electrical and Computer Engineering, University of Florida, Lightning Research Laboratory)... "It's the leading cause of insurance claims in Florida in the summer. Actually lightning is a major cause of insurance claims all over the United States." Martin Uman heads up the state's Lightning Research Laboratory...He says there's a cost for the 20 million lightning strikes in the U.S. each year... "If you average the total insurance cost for lightning in the United States over those 20 million lightnings, each of those lightnings produce about $50 worth of damage. Now every lightning doesn't cause damage and many lightnings cause a lot of damage." Uman recommends only lightning protection that has been approved by either Underwriter's Laboratory or the National Fire Protection Association. "A typical house in Florida is struck once every 50 to 75 years. So most people don't worry about structural damage. Most of the damage inside a house comes from signals coming in on the power lines because lightning can strike outside anywhere near or on the power lines." For more information, visit floridaenvironment.com. With help from its Environmental Studies Program, we're produced at the Whitaker Center at Florida Gulf Coast University and funded by the Southwest Florida Council for Environment Education. |
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| fe00706 Learning about lightning I'm Kevin Pierce with the Florida Environment. It's only been in the past decade or so that scientists have been able to count lightning. Because of that, they know there's more lightning in Florida than anywhere else in the U.S. They've also been able to learn more about the characteristics of lightning. Martin Uman heads up the state's Lightning Research Laboratory (Martin A. Uman, Ph. D., professor and chairman of Department of Electrical and Computer Engineering, University of Florida, Lightning Research Laboratory)... "The peak current and other properties of the current is what does damage when lightning hits things. And the rise time is related to the electromagnetic fields that are generated that produce induced voltages." Peak current and rise time. The current refers to lightning's power. "The peak current of a typical lightning is 30,000 to 35,000 Amps. Your household circuit has a circuit breaker that operates if you get more than 15 Amps in the circuit. Positive lightnings, which are less common but bigger, have been measured at 300,000 Amps." The rise time refers to lightning's speed to intensity... "The rise times of the fastest currents are considerable less than a millionth of a second. Actually less than a tenth of a millionth of a second." For more information, visit floridaenvironment.com. With help from its Environmental Studies Program, we're produced at the Whitaker Center at Florida Gulf Coast University and funded by the Southwest Florida Council for Environment Education. |
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fe00707 Charting lightning's future I'm Kevin Pierce with the Florida Environment. Scientists at Florida's Lightning Research Laboratory continue to make breakthroughs in their study of lightning in Florida, where there are more lightning strikes per year than anywhere else in the U.S: about 50 for every square mile. Says researcher Martin Uman, gaining the ability to count lightning -- which only became possible 10 or 15 years ago, had a dramatic effect (Martin A. Uman, Ph. D., professor and chairman of Department of Electrical and Computer Engineering, University of Florida, Lightning Research Laboratory)... "Once you see a map with a year's worth of lightning in the United States, which is something like 20 million flashes to ground -- probably 10 percent of them were in Florida -- it's just incredible." Of those 20 million strikes, at least a few were brought on by some unusual research efforts... "We initiate lightning from thunderstorms by shooting rockets up in the air, trailing wires. And if you do that at the right time, it convinces the cloud to send a lightning down through the rocket down the wire. And since the bottom of the wire can be connected to measuring equipment, you can then measure the characteristics of a lightning." Other research in looking into controlling or inhibiting lightning, something that would only be good in special situations... "There are certain facilities it would be good to keep lightning away from, for example Kennedy Space Center. So in a localized area if you could control lightning, that would be good." For more information, visit floridaenvironment.com. With help from its Environmental Studies Program, we're produced at the Whitaker Center at Florida Gulf Coast University and funded by the Southwest Florida Council for Environment Education. |
