Glossary

Cumulonimbus - This cloud is the scientific term for the "rain cloud." It is a very tall anvil shaped cloud which is characterized by severe storms and sometimes tornadoes.

Ionization - The process in which particles gain either positive or negative charges by the joining or separation of atoms.

Ionosphere - Name given to the layer(s) of ionized air in the upper atmosphere. The layer begins at around fifty miles above the surface of the earth and ends approximately four hundred miles above the surface of the earth. At these heights, the air is extremely thin, so when particles become ionized by ultraviolet rays from the sun, they usually stay ionized because the chance of collisions between particles is very slim

Leader stroke - The stream of negatively charged particles that starts off the flash, and travels to the ground or another cloud. It is followed by many other strokes during its path.

Lightning - A giant electric spark in the sky. It has numerous forms and consists of many strokes.

Lightning Arrester - Gas filled tube put on power lines to give a low resistant path to conduct electricity into the ground.

Lightning Rod - A tall metal object which sits atop the highest point on a structure. It channels lightning into the earth, thus saving the structure from electrical damage.

Meteorologist - Scientist that specialize in the field of weather. They track storms and predict where, when, and how severe the storm will be.

Stroke - The name for a part of a flash of lightning. There can be up to 46 strokes in one flash of lightning.

Thunder - The sound that you hear when lightning heats up the air surrounding it to extremely high temperatures, thus creating an explosion of sound when the hot air collides with the cooler air.

Volt - The standard unit of measurement for electricity.