Sambhav-2025

Approach  Define temperature inversion and briefly explain the concept. Explain its impact on air pollution levels. Illustrate with suitable examples. To conclude, suggest measures to mitigate the harmful effects.

Introduction

Temperature inversion is a meteorological phenomenon where the normal temperature gradient in the troposphere is reversed. Instead of temperature decreasing with altitude, a layer of warm air traps cooler air below it. This condition has significant implications for air quality, particularly in urban and industrial regions.

Body

Favorable Conditions for Temperature Inversion :

• Long winter nights: Loss of heat by terrestrial radiation from the ground surface during the night may exceed the amount of incoming solar radiation.
• Cloudless and clear sky: Loss of heat through terrestrial radiation proceeds more rapidly without any obstruction.
• Dry air near the ground surface: It limits the absorption of the radiated heat from the Earth’s surface.
• Slow movement of air: It results in no transfer or mixing of heat in the lower layers of the atmosphere.
• Snow-covered ground surface: It results in maximum loss of heat through reflection of incoming solar radiation.

Temperature Inversion significantly impacts air quality by:

• Trapping Pollutants: Under normal atmospheric conditions, warm air rises, allowing pollutants to disperse. During a temperature inversion, a stable layer of warm air acts as a lid, preventing the cooler air and pollutants from rising.
  • The lid created by the inversion layer prevents pollutants from dispersing, leading to their accumulation near the surface.
• Increased Pollution Concentration: Gases like carbon monoxide, sulfur dioxide, and nitrogen oxides, along with particulate matter, build up, causing poor air quality.
  • In 2024, New Delhi experienced hazardous air quality during winter inversions, with the Air Quality Index (AQI) soaring to 409.
• Formation of Smog: The trapped pollutants, combined with moisture, can lead to smog formation, reducing visibility and affecting health.
  • The 1952 London Smog, also known as the "Great Smog of London" was a catastrophic event caused by temperature inversion.

Implications for Human Health and Environment

• Human Health:
  • Exposure to concentrated pollutants can cause respiratory problems, asthma, and cardiovascular diseases.
  • The World Health Organization estimates that air pollution kills 7 million people every year.
• Environment:
  • Reduced visibility affects transportation and aviation.
  • Accumulated pollutants can lead to the formation of acid rain, harming ecosystems.

Conclusion

Addressing the issue requires a combination of strategies, such as reducing emissions through cleaner energy sources, monitoring weather conditions, and implementing effective urban planning to mitigate its impact on air quality