A. Troposphere – Key Characteristics:
- Lowest atmospheric layer (extends up to 8–18 km).
- Contains ~75% of atmospheric mass and ~99% of water vapour.
- Temperature decreases with altitude (lapse rate: ~6.5°C/km).
- Bounded above by tropopause, acts as weather cap.
B. Role in Weather Processes:
1. Weather Phenomena Occur Here:
- All clouds, rainfall, storms, winds, fog, snow occur in troposphere.
- Due to presence of water vapor, aerosols, and dust particles.
2. Vertical Air Movement:
- Convection currents drive cloud formation and thunderstorms.
- Influences air pressure and wind systems.
3. Heat and Energy Exchange:
- Receives heat via terrestrial radiation (from Earth’s surface).
- Differential heating causes pressure variations → wind patterns.
4. Cyclones and Monsoons:
- Low-pressure systems, monsoons, cyclones develop in this layer.
- Example: Tropical cyclones originate due to tropospheric instability.
Conclusion:
The troposphere governs all dynamic weather systems crucial for agriculture, water resources, and disaster preparedness. Its composition and processes make it the engine of Earth’s climate system.
