Topic: changes in critical geographical features (including water-bodies and ice-caps) and in flora and fauna and the effects of such changes.
Q2. What is temperature inversion and how does it influence the dispersion of atmospheric pollutants? Explain why its effects can be particularly severe in valleys and basin-like urban areas. (15 M)
Difficulty Level: Medium
Reference: DTE
Why the question
Understanding of temperature inversion as an atmospheric process and its connection with air-pollution episodes, particularly in topographically enclosed urban areas.
Key Demand of the question
Explain the concept and basic mechanism of temperature inversion, establish how it restricts the vertical and horizontal dispersion of pollutants, and explain why valleys and basin-like cities experience greater pollution accumulation under inversion conditions.
Structure of the Answer:
Introduction
Briefly introduce the normal tropospheric lapse rate and show how its reversal creates a stable atmospheric layer favourable for pollutant accumulation.Body
- Concept and formation of temperature inversion: Explain the reversal of the normal temperature gradient and briefly indicate the atmospheric conditions under which different inversions develop.
- Impact on pollutant dispersion: Show how atmospheric stability, reduced mixing height and weak vertical circulation trap pollutants near the surface and intensify pollution episodes.
- Greater severity in valleys and basins: Explain how topographic confinement, cold-air pooling and restricted ventilation reinforce inversions and pollutant accumulation in enclosed urban settings.
Conclusion
Conclude by linking air quality not merely with emission volumes but also with atmospheric stability and geographical setting, necessitating meteorology-sensitive pollution management.
