Lightning

What is it

In the early stages of the development of a thunderstorm the air acts as an insulator between the positive and negative charges so no current can flow in the clouds or between the clouds and the ground. When the opposite charges build up enough, this insulating property of the air ionises and breaks down. When this happens there is a bright flash as the air is heated to white heat and the nitrogen in the air gives it a blue tint. In a lightning flash the temperature can exceed 25,000 °C. As this happens there is a rapid expansion of the air surrounding at a speed greater than the speed of sound the discharge which is a sonic boom which we hear as thunder.

Types of Lightning

Intra Cloud

This type of lighting can be defined as one which only moves within the same cloud and then disappears. It accounts for the majority (about 75%) of all lightning activity during a thunderstorm. Intracloud flashes tend to be weaker and slower compared to cloud-to-ground lightning. They have lower peak currents, in the range of 5,000 to 30,000 amps.

Cloud to Cloud

This type of lighting can be defined as one which moves from one cloud to another cloud and then disappears. Cloud-to-cloud lightning accounts for about 20-25% of the total lightning activity during a thunderstorm. Cloud-to-cloud lightning tends to be weaker compared to cloud-to-ground flashes. The currents are typically in the range of 5,000 to 30,000 amps.

Cloud to Ground

This type of lighting can be defined as the one in which the lightning moves from the cloud towards the ground. This type of lightning can be negative as well as positive.

• Positive CG lightning - This is the more common type, making up about 70-80% of CG strikes. It originates from the positively charged region of the storm cloud.
• Negative CG lightning - This starts from the negatively charged region and makes up 20-30% of CG strikes. It tends to be more intense and damaging.

Other types

Ground to Cloud

This type of lighting can be defined as one which moves from the ground and towards the clouds. This type of lightning is very uncommon and accounts for less than 1% of all lightning strikes. Tall structures like skyscrapers, radio masts, transmission towers and wind turbines are most susceptible to triggering Ground-to-Cloud lightning.

Cloud to Air

This type of lighting can be defined as the one which takes place between clouds and the air and then disappears abruptly. Cloud-to-Air lightning is more common than cloud-to-ground lightning. It accounts for the majority of lightning activity during a thunderstorm.

Ball Lightning

Ball lightning is a rare and unexplained phenomenon described as luminescent, spherical objects that vary from pea-sized to several meters in diameter. Though usually associated with thunderstorms,[1] the observed phenomenon is reported to last considerably longer than the split-second flash of a lightning bolt, and is a phenomenon distinct from St. Elmo's fire.

Ribbon Lightning

Ribbon Lightning occurs in thunderstorms with high cross winds and many return strokes. The wind blows each successive return stroke sideways into the previous return stroke, causing a ribbon effect (Camera movement during the capture of a lightning photograph can also result in the same effect).

Staccato Lightning

Staccato lightning is a CG lightning strike, a short-duration stroke that often appears as a single very bright flash with considerable branching.