#Environment ■Lightning strikes see 34% rise than previous ye | UPSC Environment Ecology PSIR
#Environment
■Lightning strikes see 34% rise than previous year
There was 22.6% increase lightning in India last year compared to 2019.
This was revealed in the '2020 India Lightning Report ' released by Earth Networks, which operates the largest
global hyperlocal weather network.
The top five states with the most lightning last year were Tamil Nadu, Andhra Pradesh, Karnataka, West Bengal, and Odisha.
●Findings of report:
Karnataka and Maharashtra were among the top 10 States with the highest lightning pulse counts during 2020.
Over 39.5 million pulses were detected in India last year by the company's Total Lightning Network.
Odisha, followed by Chhattisgarh, experienced more than I million cloud to ground pulses last year.
Of these, 12,022,402 were dangerous cloud-to-ground strikes.
In 2020, India saw the highest concentration of lightning in May, June, and September because of the monsoon season.
●What is lightning; How does it strike?
Lightning is a very rapid and massive discharge of electricity in the atmosphere, some of which is directed towards the Earth's surface.
These discharges are generated in giant moisture-bearing clouds that are 10-12 km tall.
The base ofthese clouds typically lies within 1-2 km of the Earth's surface, while their top is 12-13 km away.
Temperatures towards the top of these clouds are in the range of minus 35 to minus 45 degrees Celsius.
As water vapour moves upward in the cloud, the falling temperature causes it to condense.
Heat is generated in the process, which pushes the molecules of water further up.
As they move to temperatures below zero degrees celsius, the water droplets change into small ice crystals.
They continue to move up, gathering mass until they are so heavy that they start to fall to Earth.
This leads to a system in which, simultaneously, smaller ice crystals are moving up and bigger crystals are coming down.
Collisions follow, and trigger the release of electrons
As the moving free electrons cause more collisions and more electrons, a chain reaction ensues.
This process results in a situation in which the top layer of the cloud gets positively charged, while the middle
layer is negatively charged.
The electrical potential difference between the two layers is huge of the order of a billion to 10 billion volts.
In very little time, a massive current, of the order of 100,000 to a million amperes, starts to flow between the layers.
An enormous amount of heat is produced, and this leads to the heating of the air column between the two layers of the cloud.
As the heated air column expands, it produces shock waves that result in thunder.
●How does Lightning Kill?
People can be hit by lightning in several ways:
1. Direct strike
2. Ground current
3. Conduction
●Statistic for Lightning:
According to the Accidental Deaths & Suicides in India 2019 report, lightning strikes accounted for more than a third of all deaths "attributable to the forces of nature" in that year.
SOURCE - THE HINDU
