🌍 1. Troposphere
- Height: Surface to about 8 km (poles) and 16–18 km (equator)
- Key Features:
- This is the lowest layer where we live.
- Contains about 75% of the atmosphere’s mass.
- All weather phenomena (rain, clouds, storms) occur here.
- Temperature decreases with height (~6.5°C per km).
👉 Important Point:
The boundary above it is called the Tropopause.
☁️ 2. Stratosphere
- Height: 18 km to about 50 km
- Key Features:
- Contains the ozone layer, which absorbs harmful UV radiation.
- Temperature increases with height due to ozone absorption of sunlight.
- Air is stable → ideal for jet aircraft flying.
👉 Boundary: Stratopause
🌌 3. Mesosphere
- Height: 50 km to 80 km
- Key Features:
- Temperature again decreases with height.
- This is the coldest layer of the atmosphere.
- Meteors burn up in this layer.
👉 Boundary: Mesopause
🔥 4. Thermosphere
- Height: 80 km to 400–700 km
- Key Features:
- Temperature increases sharply (can exceed 1000°C).
- Contains the ionosphere, important for radio communication.
- Auroras (Northern & Southern Lights) occur here.
🌠 5. Exosphere
- Height: Above 700 km up to 10,000 km
- Key Features:
- Outermost layer of the atmosphere.
- Air is extremely thin; particles can escape into space.
- Satellites orbit the Earth in this layer.
📊 Summary Table
| Layer | Height Range | Temperature Trend | Main Feature |
|---|---|---|---|
| Troposphere | 0–18 km | Decreases | Weather |
| Stratosphere | 18–50 km | Increases | Ozone Layer |
| Mesosphere | 50–80 km | Decreases | Meteors burn |
| Thermosphere | 80–700 km | Increases | Ionosphere, Auroras |
| Exosphere | 700+ km | Very high | Satellites |
🎯 Easy Trick to Remember
“T S M T E” → “The Smart Man Travels Easily”
(Troposphere → Stratosphere → Mesosphere → Thermosphere → Exosphere)