Carls Corner: The cause of lightning
By Carl Swanson | The Broadside (Contact: firstname.lastname@example.org)
When lightning, occurs when there is electrical discharge in or around a thunderstorm. The three most common types of lightning are cloud-to-ground lightning, cloud-to-cloud lightning, and cloud-to-air lightning.
Cloud-to-ground lightning occurs when the electrical charge travels between a negatively charged cloud base and the positively charged ground. The lightning strokes last only a fraction of a second, and sometimes more than one stroke is needed to discharge the electrical build-up.
Many times, the main stroke shoots out small offshoots like a spider web, out into the air displaying a spectacular light show. Only about 20 percent of lightning reaches the ground, and they normally hit tall objects first like trees and skyscrapers.
Cloud-to-cloud lightning is the most common type of lightning. The lightning travels across the sky from the negatively-charged base of the cloud to the positively charged upper part of the cloud, which lights up the sky and clouds for about a half a second. Cloud-to-cloud lightning normally occurs at high altitudes and can be seen from up to 200 miles away, but thunder can only be heard up to 20 miles away.
Cloud-to-air lightning occurs when there is a buildup of one type of charge in the cloud and a buildup of the opposite charge in the air surrounding the clouds. It’s not as powerful as cloud-to-ground lightning and usually only needs one stroke to discharge the electrical build-up. Since cloud-to-air lightning usually occurs at the top of the cloud, this type of lightning can also be seen from miles away.
To calculate how far away the thunderstorm is, starting to count right after you the lightning is seen until the thunder is heard and then dividing the number by five will give an estimate. For example, if you counted to 10 the thunderstorm is 2 miles away.
Being struck by lightning is extremely rare, and it never strikes the same place twice, but it can be fatal. When thunder roars go indoors, stay away from windows, and do not take a shower, use any electrical device, and do not hold anything that is metal like knitting needles. Lighting is attracted to metal and can travel along metal pipes and electrical circuits into your house. Going into your car is another safe place because your tires act as insulation.
If you get stuck outside stay away from trees and any metal objects like wire fencing because lightning is attracted to tall objects and can travel along wire fencing from a long distance away.
The safest thing to do is to crouch on to all fours and keep your head low, do not lie full-length on the ground, as this will increase your contact with any charges that may be conducted through the ground by wet soil. ■