How is lightning created? What are the types of lightning? Where does ball lightning come from?
It would seem that lightning is a very rare phenomenon. We happen to hear and see it at most a few times a year. However, the Earth is constantly bombarded by lightning. At any moment there are on average 2 thousand storms raging over the planet. They can strike even several tens of lightning bolts per second.
A thunderstorm is heralded by rapidly forming, huge clouds and a cool, sometimes strong wind. When we see these phenomena, we expect rain to fall. Less often do we realize that water is not the only thing that moves between the atmosphere and the Earth’s surface during a storm. Another is electrical charges, negative and positive.
A storm cloud is electrically charged. Positive charges accumulate in its upper part, and negative charges accumulate in its middle and lower parts. During a thunderstorm, the electrical potential difference between the cloud and the Earth’s surface grows rapidly until it becomes so great — on the order of 20–30 million volts — that a discharge occurs. Then lightning strikes the Earth’s surface, usually accompanied by thunder and lightning.
Lightning releases enormous amounts of energy. These are between 500 megajoules and 1 gigajoule in size. However, scientists are intensively studying a particular type of lightning called superbolt. These ultra-powerful mega-lightning bolts can be up to a thousand times more powerful than average lightning — enough to provide power for an average household for an entire year. They occur most often in winter in the northern hemisphere.
What are the types of lightning?
Lightning can be divided according to different criteria. Depending on where their “beginning” and “end” is, they are divided into:
- intra-cloud (arising within a single cloud),
- inter-cloud (strikes between two thunderstorm units),
- cloud-to-ground discharge (in rare cases also running the other way).