Source: TW
Context: 13 people were killed by lightning strikes across Bihar in the past 24 hours. The Bihar government announced Rs 4 lakh ex-gratia for each bereaved family and urged citizens to follow safety guidelines.
About Lightning:
- What is Lightning?
- A natural electrostatic discharge caused by static electricity build-up in thunderstorm clouds.
- Generates extreme heat (~50,000°F), rapidly expanding air, causing thunder.
- India’s Vulnerable Regions:
- Eastern and Northeastern states: Bihar, Jharkhand, Odisha, West Bengal, Assam.
- Parts of Madhya Pradesh, Chhattisgarh, Maharashtra, and hill regions are also prone.
- Principles Behind Occurrence:
- Charge Separation in Clouds: Inside thunderclouds, colliding water droplets, ice crystals, and hailstones create separation of electric charges—positive charges rise to the top, while negative charges accumulate at the bottom.
- Electrostatic Build-Up: The earth’s surface becomes positively charged in response to the cloud’s negative base, further intensifying the electrical potential.
- Threshold Breach: When the electric field strength exceeds the insulating capacity of the air, the energy discharges violently as lightning, balancing the charge difference.
- Path of Discharge: The discharge can travel cloud-to-cloud, intra-cloud, or ground-to-cloud, producing a sudden flash of light and a shockwave heard as thunder.
- Significance of the Hazard:
- Lightning is one of India’s leading natural disaster killers, especially affecting farmers, labourers, and outdoor workers.
- On average, lightning causes over 2,000 deaths annually in India.
- It impacts agriculture, rural livelihoods, and contributes to climate vulnerability.
- Key Initiatives Taken in India:
- Damini App (IITM): Sends real-time lightning alerts within a 40-minute window based on location.
- Lightning Detection Network (LLN) and Doppler radars monitor lightning strikes.
- IMD forecasts: Provide nowcast (2-3 hrs), short-range (1-3 days), and medium-range alerts.
- Lightning Resilient India Campaign (CROPC & IMD): Targets 80% reduction in deaths through rural education.
- NDMA guidelines: Advise states on mapping risk zones, data sharing, and safety infrastructure.
