Physics

 

When the positive and negative charges within a cloud separate the electric field inside the cloud begins to grow in strength. This is result of the fact that electrical charges of a similar charge repel one another and oppposite charges attract. Due to the fact that the atmosphere around a cloud acts as a very strong insulator, a significant amount of charge must be built up before an electrostatic discharge(lightning) can occur. The reason most lightning occurs within the cloud itself is because the electric fields within the cloud are oftentimes much stronger than those between the bottom of the cloud and the surface of the ground.

 

The electric field line map diagrammed in the image above shows a typified electrical interaction between the clouds and the ground. Observe that the height of the tree over its surroundings has caused the electric field lines to concentrate in that area. In a diagram such as this the electric field is always stronger where the electric field lines are closer together. Where the electric field is very strong there is a high probability that elecdtrons will be forced out of the cloud and attracted to the ground.

 

Photo courtesy of www.strikingimages.com

A lightning storm

 

Title Page

What Causes Lightning

Types of Lightning

Credits