For lightning Caused by electrostatic discharge from cumulonimbus cloud or clouds, Nimbus Lo accumulator. (Cumulonimbus) is a large chunk. The cloud base to a height of approximately two kilometers and the cloud tops as high as 20 kilometers inside the cloud is the flow of air flows fast and furious. Making water drops and ice in clouds, causing Coulomb friction. It was found that the positive charge is located on top of the clouds. The negatively charged area of the cloud base. The negatively charged cloud base may induce the earth's surface under the shadow of it with a positive charge.