The term lightning 'strike' refers to cloud-to-ground lightning, where lightning 'strikes' the ground. A lightning flash is what you can see, but this is often made up of several individual lighting strokes which are pulses of current which occur separately if though only hundredths of a second apart. Lightning flashes and lightning strikesĪlthough often assumed to be the same thing, there is a key distinction between lightning flashes and lighting strikes. As the attraction between the cloud and the ground grows stronger, electrons shoot down from the cloud cutting through the air at around 270,000 miles per hour. This leaves the ground and the objects on it with a positive charge. The path they make in doing so forms the channel we see during a flash of lightning.Īs negative charge builds at the base of the cloud, the electrons near the ground's surface are repelled. If the attraction is strong enough, the electrons will rapidly move towards the positive atoms. As well as being attracted to the positive charge in the top of the cloud, the surplus of electrons in the cloud base are attracted to positive charge in other clouds and on the ground. The hail continues to fall through in the lower part of the cloud, giving it a negative charge. The updraughts continue to carry the ice particles upwards, giving the top of the cloud a positive charge. During these collisions, electrons are transferred to the hail giving the hail a negative charge, while the ice particles that have lost electrons gain a positive charge. Some of the hail that forms becomes too heavy to be propelled by the updraughts and so begin to fall back through the cloud, bumping into smaller ice particles as they do so. Some of the pieces of ice grow into hail, but others remain very small. As tiny water droplets form inside a storm cloud, they are propelled towards the top of the cloud by strong internal winds (updraughts) where they turn to ice.
0 kommentar(er)
