Part 1: Atmosphere Fundamentals
Earth's Atmospheric Envelope
The atmosphere is the thin layer of gases surrounding Earth, held in place by gravity. It protects life from harmful radiation, regulates temperature, and enables weather and climate. Understanding its structure and composition is fundamental to atmospheric science.
99%
Below 30 km altitude
1013 hPa
Sea-level pressure
288 K
Mean surface temp
Topics in This Part
Key Concepts
Scale Height
$$H = \frac{R_d T}{g} \approx 8.5 \text{ km}$$
Height over which pressure drops by factor e
Barometric Formula
$$p(z) = p_0 e^{-z/H}$$
Pressure decreases exponentially with altitude