Why in the news?

  • As per the National Crime Records Bureau (NCRB) report Accidental Deaths and Suicides in India, lightning was responsible for the highest number of deaths in 2023, accounting for 39.7% of the 6,444 deaths attributed to ‘forces of nature’.

Lightning

  • Definition: A lightning bolt is a sudden electrostatic discharge during a thunderstorm, which occurs between electrically charged regions within clouds, or between clouds and the ground.
  • Recent Data:
    • In the last few years, lightning has emerged as a new climate challenge for India, which has seen a 400 per cent rise in lightning strikes from 2019-20 to 2024-25. 
    • Under lightning strikes, Madhya Pradesh (397), Bihar (345), Odisha (294), Uttar Pradesh (287), and Jharkhand (194) were the biggest victim states/Union Territories (UTs).
  • Formation Process:
    • Charge Separation:
      • In cumulonimbus clouds, collisions between ice particles cause separation of electric charges.
      • Positive charges gather at the top; negative charges at the base.
    • Electric Potential Build-up:
      • The difference in charge between cloud regions or between cloud and ground becomes intense.
      • Ground beneath the cloud becomes positively charged due to induction.
    • Discharge (Lightning Bolt):
      • When the electric field exceeds the insulating capacity of air (~3 million volts/m), a discharge occurs.
      • Electrons travel downward (stepped leader), then upward streamers rise from the ground.
      • Upon connection, a return stroke travels back up, producing the visible lightning bolt.
  • Types of Lightning:
    • Cloud-to-Ground (CG): Most dangerous to life and property.
    • Intra-Cloud (IC): Most common, occurs within the same cloud.
    • Cloud-to-Cloud (CC): Between two separate clouds.
    • Ground-to-Cloud (GC): Rare upward-moving lightning.
  • Associated Phenomena:
    • Thunder: Sound caused by the rapid expansion of air due to intense heat (~30,000°C).
    • Electromagnetic Disturbances: Can disrupt radio, navigation, and power systems.
  • Impacts:
    • Hazards:
      • Fatal to humans and animals.
      • Causes forest fires, power outages, structural damage.
    • Scientific Utility: Lightning helps fix atmospheric nitrogen into usable nitrates for plants.
  • Mitigation and Safety:
    • Use lightning rods for buildings.
    • Follow “30-30 Rule”: If thunder is heard within 30 seconds of lightning, seek shelter.
    • Avoid open fields, water bodies, and tall isolated trees during a storm.