What is lightning?
Lightning is believed to have become the costliest weather related force. The reason is the proliferation of electronic equipment that is highly susceptible to damage or destruction from lightning-induced voltage and currents as well as direct strikes. How Lightning Selects a Target A typical cloud-to-ground flash is initiated when an avalanche of free electrons sets off from the base of a thundercloud toward the intense positive charge that has been building up below. This first “stepped leader stroke” approaches ground in discrete steps of about 100 to 150 feet or more. This channel is composed of negatively charged air molecules and is not the actual lightning strike. It is barely visible but can carry currents of 100 to 1,000 amperes or more. As the “stepped leader approaches the earth the ground s positive charge increases sharply. Near the ground electrons are stripped away by air molecules creating positively charged channels. These channels reach up toward the leader. The chann
Lightning is a discharge of atmospheric electricity which is triggered by a buildup of differing charges within a cloud. The result is a sudden release of electricity which causes a distinctive bright flare, followed by a thunderclap. Lightning is most common around the equatorial regions of the world, although it can potentially strike anywhere, and it appears in a variety of guises, depending on atmospheric conditions. There are several competing theories to explain why differing electrical charges appear in clouds, although scientists suspect that it may be related to the presence of ice crystals in the cloud. Typically, the bottom of a cloud become negatively charged, and it sends out what is known as a “leader” which seeks a positive charge, either in another cloud or on the earth. As the leader approaches an area which is positively charged, a positively charged streamer emerges, meeting the leader, sealing the connection, and generating a bolt of lightning. After the lightning t
The action of rising and descending air within a thunderstorm separates positive and negative charges. Water and ice particles also affect the distribution of electrical charge. Lightning results from the buildup and discharge of electrical energy between positively and negatively charged areas. Most lightning occurs within the cloud or between the cloud and ground. The average flash of lightning could turn on a 100-watt light bulb for more than 3 months. The air near a lightning strike is hotter than the surface of the sun! The rapid heating and cooling of air near the lightning channel causes a shock wave that results in thunder. Your chances of being struck by lightning are estimated to be 1 in 600,000 but those chances can be reduced by following safety rules. Most lightning deaths and injuries occur when people are caught outdoors, and most happen in the summer. Many fires in the western United States and Alaska are started by lightning. In the past 10 years, more than 15,000 fire
Lightning is a gigantic electrostatic discharge (the same kind of electricity that can shock you when you touch a doorknob) between the cloud and the ground, other clouds, or within a cloud. Scientists do not understand yet exactly how it works or how it interacts with the upper atmosphere or the earth ‘s electromagnetic field. Lightning is one of the oldest observed natural phenomena on earth. It has been seen in volcanic eruptions, extremely intense forest fires, surface nuclear detonations, heavy snowstorms, in large hurricanes, and obviously, thunderstorms.
Lightning is a kick-butt jolt of electricity that can travel inside a cloud, between clouds, or from a cloud to Earth. There’s no real consensus on how clouds accumulate such huge charges. The Why Files asked David Martin, a scientist at the University of Wisconsin-Madison’s Space Science and Engineering Center to explain the most plausible theory. Photo ©Daniel Robinson Martin told us that differences in temperature cause updrafts in thunderstorms. These fast vertical winds contain large and small particles of ice, and supercooled water (water that’s cold enough to freeze, but has not yet frozen). As the water and ice collide, positive and negative charges separate. The updrafts then move the charges, forming the cloud into a sandwich with negative charges in the middle, and positive ones at the top and bottom. Map courtesy of National Weather Service, Jackson, Mississippi. When enough charges accumulate, the resulting electrical potential, or voltage, overcomes the air’s electrical r
