LIGHTNING

About: 

• Lightning is a giant spark of electricity in the atmosphere between clouds, the air, or the ground.
  
  
• Formation of lightning:
  • Air generally acts as an insulator between the positive and negative charges in the cloud and between the cloud and the ground.
    
    
  • But when the opposite charges build up enough, this insulating capacity of the air breaks down and there is a rapid discharge of electricity that we know as lightning.
    
    
  
  
  
• It is of three broad types:
  • Cloud to ground (CG): Lightning originates in atmosphere and terminates on the ground.
    
    
  • Ground to cloud (GC): it involves upward propagation of lightning initiated from a tall grounded object and reaches into the clouds. It is the least common type.
    
    
  • Cloud to cloud (CC): In this discharges only occur high in the atmosphere. The bulk of lightning events are cloud to cloud (CC).
    
    
  
  
  
• Lightning rod: It is used to mitigate lightning damage and influence the path of a lightning flash. It is a metal strip or rod connected to earth through conductors and a grounding system, used to provide a preferred pathway to ground if lightning terminates on a structure.
  
  
• Lightning can cause injuries in several ways:
  • Direct strike: Victims may sustain a direct strike, which is often fatal.
    
    
  • Contact injury: This occurs when lightning strikes an object, such as a car or metal pole, that the victim is touching.
    
    
  • Side flash: This occurs when lightning splashes or bounces off an object, such as a tree or person, onto the victim.
    
    
  • Ground current: This occurs when lightning strikes the ground near a victim and the ground current passes from the strike point through the ground and into the victim.
    
    
  
  
  
• Lightning related deaths in India:
  • According to the National Crime Records Bureau (NCRB) data, as a whole, India sees 2,000-2,500 lightning deaths every year on average. Lightning is the biggest contributor to accidental deaths due to natural causes.
    
    
  • Regions most affected: Eastern states of Assam, West Bengal and Odisha report the highest fatalities due to lightning. North-eastern states, Maharashtra, Kerala, Jharkhand and Bihar also suffer heavy casualties.
    
    
  
  
  
• Government steps: Lightning remains among the least studied atmospheric phenomena in the country. Just one group of scientists, at the Indian Institute of Tropical Management (IITM) in Pune, works full-time on thunderstorms and lightning.