Lightning: flash and thunder
Electrically charged ice crystals
It forms in thunderclouds due to the separation of charges caused by the mixing of warm and cold air currents. In the cold air, there are ice crystals, while in the warm air, there are water droplets. When warm air rises and collides with cold air, the droplets rub against the ice crystals. As a result, both become electrically charged. The lower part of the thundercloud carries a negative charge, while the upper part carries a positive charge.
As a result, the lower part of the cloud becomes electrically charged with a negative charge. Due to the much larger accumulation of negative charge in the cloud compared to the Earth's surface, a discharge occurs, and part of the negative charge from the cloud is transferred to the Earth. This discharge is seen as a lightning strike, which consists of a flash of light and thunder.
Light travels much faster than sound. From the time difference, we can estimate the distance to their source. A 1-second difference corresponds to a distance of about 300 meters.
Types of lightening
Not all lightning strikes are the same, and they are classified based on their place of origin. We know of those that occur between clouds, within a cloud, or between a cloud and the Earth. Approximately 10 percent of all lightning strikes hit the Earth's surface. Depending on the path of the lightning, we classify them as either downward or upward strikes. Based on the charge, we differentiate between those that strike from the lower part of the cloud (negative charge) and those that strike from the upper part of the cloud (positive charge). Most lightning strikes carry a negative charge. However, lightning that strikes from the top of the cloud is much stronger and lasts longer. These strikes cause more damage and can ignite fires, which is why they are often referred to as "fire lightning." Such strikes are frequently called "lightning from a clear sky," as they strike from the top of the cloud.
Protection from lightning strike
During a storm, the safest place is a large building equipped with multiple lightning conductors. These are long metal rods that direct the lightning strike into the ground if it hits. It is also safe inside a car, as the metal chassis conducts the lightning charge away from the passengers to the ground. If you happen to be caught in a storm, never run or seek shelter under a tree! Even if the lightning doesn't kill you directly, the heat released by the strike can boil the sap inside the tree, causing it to explode! When lightning strikes the ground, the current flows outward from the center of impact. If you stand with your legs apart, the current could flow up one leg and down the other, which can cause fatal injuries. Many cattle die in this way because they can't keep their legs together to maintain balance.
DO YOU KNOW?
- Due to the consequences of lightning strikes, it is estimated that around 1,000 people die worldwide each year.
- In 1971, in what is now the African country of Zimbabwe, 21 people died due to a direct lightning strike on a hut.