According to wikipedia, “A lightning strike or lightning bolt is an electric discharge between the atmosphere and the ground. ” It mostly occurs within the cloud but when it does strike the earth, it can cause serious damage to life and property. About 240,000 lightning strike incidents happen each year globally and according to National geographic, about 2000 annual deaths occur due to lightning strikes. About 41 people died in Uttar Pradesh (India) and 23 in Rajasthan (India) and about 21 were injured due to lightning strikes on Sunday (11 July, 2021).
How does lightning occur?
Clouds consist of electric charges (positive and negative) that are usually balanced but the winds of a storm result in a separation of charges within the clouds. Positively charged particles occupy the top of the cloud and the negatively charged particles concentrate on the bottom. This separation of charges result in the flow of electricity.
Types of lightning bolts-
There are 3 main types of lightning bolts-
- Cloud-to-cloud: When charged particles of one cloud are attracted to the oppositely charged particles of another cloud, it is known as cloud-to-cloud lightning. It is the most common form of lightning in the sky.
- Cloud-to-air: When the discharge moves from the cloud to the sky and is attracted to the charged particles of air, it is referred to as cloud-to-air lightning.
- Cloud-to-ground: Negative charge- In this type of flow of lightning, the negatively charged particles begin to move towards the ground in a zig-zag path( also known as stepped leader) . They move with such high speed that they reach the ground in about a millisecond. When they reach the ground, they attract positive charges(also known as an upward leader or streamer) that begin to move towards them (usually through tall buildings, trees, etc.). When the stepped leader and streamer meet, it leads to a flow of powerful current from the ground to the cloud. Positive charge- When the positive charge of cloud overcome the negative charge and travel towards the earth meeting negative stream of charges coming from the earth , it is referred to as CG lightning-positive charge. It, though uncommon, is more dangerous.
5 ways lightning strikes people –
- Direct strikes- The most deadly, it usually occurs to people who are in open areas. When lightning strikes the body,, some of the current moves through the body and some moves along and over the body( which produces heat that can cause skin burns).
- Side flash- It occurs when the victim is standing next to a taller object and some of the current from the taller object is transferred to the body of the victim, which is why you should avoid taking shelter under a tree when lightning strikes.
- Ground Current- When lightning strikes a tall body, much of the energy leaves the body and is either side flashed or transferred to the ground. The current transferred to the ground affects a larger area as it can transfer through conducting materials, which is why you should avoid being outside during lightning flashes.
- Conduction- Lightning can travel through potentially conducting surfaces like barbed wires who provide a pathway for lightning to travel very large distances.
- Streamers- People caught in streamers formed during cloud-to-ground transition of lightning will find it very difficult to come out of it and it can result in death.
How to protect yourself from lightning?
- Avoid going outdoors during lightning strikes and even if you do end up being in the outdoors, immediately find an enclosed shelter.
- Do not, under any circumstance, take shade under a tree or be near one.
- If you are inside your car, do not get out. But ensure that your car is parked in an open space away from potential charge attracters or conductors.
- Avoid being near water. Do not bathe (even inside your house) and stay away from rivers, lakes or any other water body.
- Try to minimize your surface area, when outside. Do not lie flat and crouch into a ball-like-position.