What is lightning?
Lightning is a naturally occurring electrostatic discharge during which two electrically charged regions, both in the atmosphere or with one on the ground, temporarily neutralize themselves, causing the instantaneous release of an average of one gigajoule of energy.
It is accompanied by a bright flash, a loud sound, and occasionally thunderstorms.
How does lightning work?
During a storm, water droplets in warmer air and ice crystals that condensed in cooler air coalesce together to form thunderstorm clouds (usually cumulonimbus clouds).
Contact between these droplets and crystals produces a static electrical charge in the clouds.
The negative and positive charges in the clouds build up.
Over time, the voltage difference becomes high enough to surmount the resistance presented by the air, leading to a rapid discharge of electric charge. This is what we see as a lightning flash.
Lightning Concerns
Lightning strike
A lightning strike or lightning bolt is an electric discharge between the atmosphere and the ground.
Most originate in a cumulonimbus cloud and terminate on the ground, called cloud-to-ground (CG) lightning.
Cloud-to-ground (CG) lightning is dangerous because it can electrocute people due to its high electric voltage and current.
Inter- or intra-cloud lightning is visible and safe.
Lightning strikes can produce severe injuries, and are lethal in between 10 and 30% of cases, with up to 80% of survivors sustaining long-term injuries.
The heat created by lightning currents travelling through a tree may vaporize its sap, causing a steam explosion that bursts the trunk.
As lightning travels through sandy soil, the soil surrounding the plasma channel may melt, forming tubular structures called fulgurites.
Effects on buildings and vehicles.
Common injuries caused by lightning include: muscle pains, broken bones, cardiac arrest, confusion, hearing loss, seizures, burns, behavioral changes, and ocular cataracts.
Loss of consciousness is very common immediately after a strike.
Is lightning a climate indicator?
Long-term changes in lightning patterns reflect, (at least in part), changes wrought by the climate crisis.
The World Meteorological Organisation recognises lightning to be an essential climate variable that contributes critically to the way the earth’s climate is characterised.
According to Eos, a publication of the American Geophysical Union, lightning also produces nitrogen oxides, which react with oxygen in the air to form ozone, which is a strong greenhouse gas.
Lightning strikes in India
Lightning strikes have been the deadliest natural disaster in India.
There were 18.5 million lightning strikes in the country between April 2020 and March 2021 – 34% higher than the previous year – according to the Climate Resilient Observing Systems Promotion Council.
The Indian Institute of Tropical Meteorology, Pune, has also reported a sharp uptick in strikes in the decade since 1995.
Per a report of the Lightning Resilient India Campaign, 90,632 people died by lightning between 1972 and 2019.
According to the National Crime Records Bureau, India had 2,875 deaths due to lightning in 2019, rising marginally by 2021.
The private weather-forecasting company Skymet has reported that Odisha recorded the most strikes among India’s states in 2019.
However, the Campaign report also said strikes had dropped by 60% in Odisha, Andhra Pradesh, and Nagaland in 2021-2022.
It also said that most such deaths in India happen because people living in villages seek shelter from lightning under tall trees, which are more likely to be struck.
States are demanding to declare it as a “declared natural disaster in India”.
Declared Natural disasters in India
According to present norms, cyclone, drought, earthquake, fire, flood, tsunami, hailstorm, landslip, avalanche, cloudburst, pest attack, frost and cold waves are considered as natural disasters.
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