Lightning Lightning

By Ashley MildrenBy Ashley Mildren

How Rain FormesHow Rain Formes

Lightning comes from thunder clouds, known as Lightning comes from thunder clouds, known as cumulonimbus. These are created when hot moist air cumulonimbus. These are created when hot moist air rises in to the atmosphere and condenses. Hot air rises rises in to the atmosphere and condenses. Hot air rises when it is heated by the sun, carrying water vapour into when it is heated by the sun, carrying water vapour into the sky. As it rises, the hot air mixes with colder air, and the sky. As it rises, the hot air mixes with colder air, and the moisture condenses into water droplets. Clouds are the moisture condenses into water droplets. Clouds are created when these water droplets become visible. The created when these water droplets become visible. The droplets increase in size as the cloud grows and droplets increase in size as the cloud grows and eventually becoming so heavy that they fall as rain. eventually becoming so heavy that they fall as rain. Thunder clouds are large, anvil-shaped masses that can Thunder clouds are large, anvil-shaped masses that can stretch miles across at the base, and reach 40,000 feet stretch miles across at the base, and reach 40,000 feet or more in to the atmosphere. or more in to the atmosphere.

http://www.eo.ucar.edu/kids/dangerwx/tstorm5.htm

Lightning happens when Lightning happens when the negative charges the negative charges (electrons) in the bottom (electrons) in the bottom of the cloud are attracted of the cloud are attracted to the positive charges to the positive charges (protons) in the ground. (protons) in the ground.

The accumulation of The accumulation of electric charges has to be electric charges has to be great enough to great enough to overcome the insulating overcome the insulating properties of air. When properties of air. When this happens, a stream of this happens, a stream of negative charges pours negative charges pours down towards a high down towards a high point where positive point where positive charges have clustered charges have clustered due to the pull of the due to the pull of the thunderhead.thunderhead.

The connection is made The connection is made and the protons rush up and the protons rush up to meet the electrons. It is to meet the electrons. It is at that point that we see at that point that we see lightning and hear lightning and hear thunder. A bolt of thunder. A bolt of lightning heats the air lightning heats the air along its path causing it along its path causing it to expand rapidly. to expand rapidly. Thunder is the sound Thunder is the sound caused by rapidly caused by rapidly expanding air. expanding air.