🌍 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

🎯 Easy Trick to Remember

“T S M T E” → “The Smart Man Travels Easily”
(Troposphere → Stratosphere → Mesosphere → Thermosphere → Exosphere)