Lightning is the visible discharge of static electricity within a cloud, between clouds, or between the earth and clouds.
Scientists still do not fully understand what causes lightning, however most experts believe that different kinds of ice interact in a cloud. Updrafts in the clouds separate charges so that positive charges move up to the top of the clouds, while negative flow to the bottom. When the negative charge moves down, a “pilot leader” forms. This leader rushes toward the earth in 50 meter discrete steps, ionizing a path in the air. ‘The final breakdown generally occurs to a high object, the major part of the lightning discharge current is then carried in the return stroke which flows along the ionized path.
Lightning is a naturally occurring electrostatic discharge during which two electrically charged regions in the atmosphere or ground temporarily equalize themselves, causing the instantaneous release of as much as one billion joules of energy. This discharge may produce a wide range of electromagnetic radiation, from very hot plasma created by the rapid movement of electrons to brilliant flashes of visible light in the form of black-body radiation. Lightning is often followed by thunder, an audible sound caused by the shock wave which develops as gases in the vicinity of the discharge experience a sudden increase in pressure. It occurs commonly during thunderstorms and other types of energetic weather systems.