Lightning
- For the NHL team, see Tampa Bay Lightning
- For the World War II fighter, see P-38 Lightning
Lightning is a very powerful electrical discharge made during a thunderstorm. The electric current makes the air very hot. The suddenly heated air expands very quickly, which causes thunder. Sometimes lightning happens between clouds. Sometimes (in the rain) lightning goes from cloud to ground. If it goes from cloud to ground, it can strike a person. Around 2000 people are struck by lightning each year. A few of them are not killed. About 50 to 100 lightning bolts strike the Earth every second.[1][2] Lightning has hit the Empire State Building as many as 500 times a year. A bolt of lightning can reach temperatures hotter than the surface of the sun.[3]
When lightning strikes, the surface rubs electrons from the lightning, and a spark of electricity shoots from the lightning to the surface. In a thunderstorm, the lower cloud has as many as 100 million volts of electricity.[1] This electricity is given out either within the cloud, to the ground, to another cloud, or into the air. Lightning has been known to travel from the ground upwards to the cloud. In 1993, scientists discovered lightning bolts that shot upward from the top of a cumulonimbus cloud.[1]
People can make and study lightning with a Tesla coil or a Van de Graaff Generator.
Franklin experiment
Benjamin Franklin experimented with electricity and was interested in lightning. He discovered many things about lightning. In 1772, he was the first to show that a thunderstorm lets out electricity.[1] In his book he suggested an experiment to test it. Joseph Priestley said that Franklin flew a kite to prove the presence of electricity in the storm, using a dry silk string to protect himself from the electricity in the wet hemp kitestring. [2]
Lightning Media
Strokes of cloud-to-ground lightning strike the Mediterranean Sea off of Port-la-Nouvelle in southern France.
(Figure 1) The main charging area in a thunderstorm occurs in the central part of the storm where the air is moving upward rapidly (updraft) and temperatures range from −15 to −25 °C (5 to −13 °F).
(Figure 2) When the rising ice crystals collide with graupel, the ice crystals become positively charged and the graupel becomes negatively charged.
The upper part of the thunderstorm cloud becomes positively charged while the middle to the lower part of the thunderstorm cloud becomes negatively charged.
Four-second video of a lightning strike at Canyonlands National Park in Utah, U.S.
Data obtained from April 1995 to February 2003 from NASA's Optical Transient Detector depicting space-based sensors revealing the uneven distribution of worldwide lightning strikes
A downward leader travels towards earth, branching as it goes.
Lightning strike caused by the connection of two leaders, positive shown in blue and negative in red
Upwards streamer emanating from the top of a pool cover
Cloud to ground seen in slow motion
Related pages
References
- ↑ 1.0 1.1 1.2 1.3 Oard, Michael (1997). The Weather Book. P.O. Box 126, Green Forest, AR 72638: Master Books. ISBN 0-89051-211-6.
{{cite book}}: CS1 maint: location (link) - ↑ 2.0 2.1 "Lightning".
- ↑ US Department of Commerce, NOAA. "How Hot Is Lightning?". www.weather.gov. Retrieved 2024-09-08.