A lightning flash can be seen anywhere on Earth, but thunderstorms are most common in tropical and temperate regions.
Lightning is caused by the combination of water vapor in clouds and electricity passing through them.
When lightning strikes, it heats up the air around it so fast that the air expands a lot. This expansion causes a shock wave to form in the air and it is what creates the sound of thunder.
The noise of thunder is created by rapid heating and cooling of the air around a lightning channel.
You can learn how to tell how far away the lightning is by counting the seconds after the lightning flashes until you hear a loud rumble of thunder. If you are close enough to a lightning strike, you may hear a crack or boom of thunder, but if it is further away, the sound will be continuous and low pitched.
There are two types of lightning: downward triggered (IC) and upward triggered (CG). The latter occurs because the electricity in a cloud moves from high to lower layers.
Upward triggered lightning is most often triggered by artificial means such as tall structures or rockets.
When lightning strikes, it causes the lighter positive ions in the air to move up, while the heavier negative ions settle. This changes the charge in the cloud and forces it to try to discharge itself, neutralize itself, or disperse itself.
