Lightning is an electrical discharge between clouds, within a cloud, between clouds and the earth, or between a cloud and the air. The discharge can have up to 100 million volts of electricity and may reach 60,000 degrees Fahrenheit. The discharge rapidly heats the air which expands abruptly making a sound wave we call thunder. The bright flash of light that is seen is called a return stroke which travels approximately the speed of light (186,282 miles per sec.). A stroke of lightning between a cloud and the ground can be up to 9 miles long. A stroke of lightning between one cloud to another can be up to 90 miles long. Lightning strikes the earth approximately 100 times per second. Approximately 100 people in the U.S. are killed from lightning each year and many more are injured. Lightning causes about 10,000 forest fires and 40% of all farm fires. One stroke of lightning takes about one fifth of a second to strike. Lightning is five times hotter than the surface of the sun. Enough electric charge is in one stroke to light an entire city.
Lightning has always been one of nature's greatest mysteries. The serious study of lightning began in the 1700's. The Greeks and Romans thought that lightning was the "weapon of the gods". In Africa people presupposed that humans and places that were struck by lightning were cursed. Some people in Europe and America thought that lightning could be kept away by ringing church bells. In 1752 Benjamin Franklin showed that lightning is an electricity by flying a kite in a storm. On the kite string was a key and the lightning caused sparks to jump from the key to grounded objects.
Types of Lightning:
Forked lightning is a stroke of lightning that has a many branches.
Streak lightning is a flash that appears as one single jagged line.
Ribbon lightning occurs when the wind separates a stroke of lightning creating parallel strokes.
Bead or chain lightning occurs when a flash breaks up into a dotted line as it fades.
Heat Lightning seems to have no thunder because it is too far away to hear.
Sheet lightning occurs when the sky is lit with flashes but it is too far away to see or the display is hidden by clouds.
Ball lightning is a rare phenomenon. It appears as a glowing ball that floats as it fades. It can appear red, yellow, or orange.
Lightning Preparedness
Some things you should remember in a lightning storm:
- Go into a house or large building for shelter, don't touch metal.
- In emergencies only: use the phone.
- If you are in an open area, crouch down.
- If the only shelter you can find is a car, stay inside the car and roll up the windows. Do not get out of the car or touch any metal parts.
- Do not stand near an isolated object like a flag pole or tree.
- Stay away from water and metal vehicles.
- If in a pool or at the beach when lightning is sighted, get out of the water immediately! Water is one of the best conductors of electricity!
- If caught in the forest, hide under the shrubs.
- If someone is struck, they should be treated with C.P.R.
- Install lightning rods to buildings to ground the electric discharge.
Lightning can occur in any type of storm: thunderstorms, snowstorms, sandstorms, ice storms, or during volcanic eruptions!
TOP