Cloud-to-ground lightning, also known as CG lightning, refers to a type of electrical discharge that occurs between a cloud and the Earth's surface. It is an atmospheric phenomenon characterized by a visible, powerful and intense flash of light, accompanied by a sharp cracking or rumbling sound called thunder. This type of lightning occurs when there is a difference in electrical charge between a storm cloud and the ground.
Cloud-to-ground lightning can be further divided into two main categories: negative CG lightning and positive CG lightning. Negative CG lightning is more common and accounts for approximately 90% of cloud-to-ground lightning strikes. It forms when negatively charged electrons are discharged from the cloud towards the positively charged ground. Positive CG lightning, on the other hand, is less frequent but tends to be more powerful and can travel longer distances. It occurs when positively charged electrons are discharged from the cloud towards the negatively charged ground.
Cloud-to-ground lightning poses various risks and hazards, including property damage, wildfires, and an increased likelihood of electrical injuries or fatalities to humans and animals. It can also disrupt power grids, communication systems, and cause fires or explosions. Thunderstorms, which often feature cloud-to-ground lightning, exhibit a complex interplay of atmospheric conditions, such as the presence of moisture, temperature differentials, and convective winds.
Meteorologists and scientists study cloud-to-ground lightning to better understand its behavior, predict storms, and improve safety measures. Lightning rods and other lightning protection systems are commonly used as a means to mitigate the potential damage caused by cloud-to-ground lightning strikes.
