How lightning kills, and how to be safe when it strikes?

Of all the atmospheric phenomena, lightning perhaps is the most dangerous and mysterious. In India, lightning kills about 2,000-2,500 people every year. Recently, Seventeen people have been in various parts of Bihar, Six deaths have been reported from Bhagalpur district, while three people were killed in Vaishali and two each in Banka and Khagaria.

About Lightning:

• Scientifically, lightning is a rapid and massive discharge of electricity in the atmosphere some of which is directed towards earth, generated in giant moisture-bearing clouds.
• Distance of the clouds from the earth’s surface:
  • Base of the clouds: 1-2km from the Earth’s surface
  • Top of the clouds: 12-13km
• Temperature at the top of the clouds: -35^oC to -45^oC

How the lightning is formed?

• As the water vapour moves upward in the clouds, the falling temperature converts the vapour into tiny ice crystals, as the temperature is below the freezing point.
• Collisions follow and trigger the release of electrons, the moving free electrons cause more collisions and more electrons, a chain reaction ensues. 
• This process results into a situation of formation of layers of clouds with alternate positive and negative charge with a huge potential difference, of the order of a billion to 10 billion volts.
• As Earth is a good conductor of electricity 15-20% of the electricity generated by the process is directed to the Earth surface, creating the lightning situation.