Eventually, the whole cloud fills up with electrical charges. Lighter, positively charged particles form at the top of the cloud. Heavier, negatively charged particles sink to the bottom of the cloud.
When the positive and negative charges grow large enough, a giant spark - lightning - occurs between the two charges within the cloud. This is like a static electricity sparks you see, but much bigger.
Most lightning happens inside a cloud, but sometimes it happens between the cloud and the ground. A build up of positive charge builds up on the ground beneath the cloud, attracted to the negative charge in the bottom of the cloud. The ground's positive charge concentrates around anything that sticks up - trees, lightning conductors, even people! The positive charge from the ground connects with the negative charge from the clouds and a spark of lightning strikes.
Go to What is lightning? Lightning is an amazing natural phenomenon. Use it to discuss the nature of electricity, charge and the transfer of electrical energy into heat, light and sound. Planet Science. Advanced Search. Under 11s. Lightning is a giant spark of electricity in the atmosphere between clouds, the air, or the ground. In the early stages of development, air acts as an insulator between the positive and negative charges in the cloud and between the cloud and the ground.
When the opposite charges build up enough, this insulating capacity of the air breaks down and there is a rapid discharge of electricity that we know as lightning. The actual breakdown process is still poorly understood. The air breakdown creates ions and free electrons that travel down the conducting channel. This current flow temporarily equalizes the charged regions in the atmosphere until the opposite charges build up again. Lightning from thunderstorms begins in a strong electric field between opposite charges within the storm cloud, and can stay completely within the cloud intra-cloud lightning when the charge regions are similar strength balanced or can reach the ground cloud-to-ground lightning when one of the regions is much stronger than the other unbalanced.
Lightning is one of the oldest observed natural phenomena on earth. So, do thunderclouds have rubber shoes? Not exactly, but there is a lot of shuffling going on inside the cloud. Lightning begins as static charges in a rain cloud. Winds inside the cloud are very turbulent. Water droplets in the bottom part of the cloud are caught in the updrafts and lifted to great heights where the much colder atmosphere freezes them. Meanwhile, downdrafts in the cloud push ice and hail down from the top of the cloud.
Where the ice going down meets the water coming up, electrons are stripped off. It's a little more complicated than that, but what results is a cloud with a negatively charged bottom and a positively charged top. These electrical fields become incredibly strong, with the atmosphere acting as an insulator between them in the cloud.
Lightning happens. The electric field "looks" for a doorknob. Sort of. It looks for the closest and easiest path to release its charge. Often lightning occurs between clouds or inside a cloud.
0コメント