Layers of the Atmosphere
Divided up by: Temperature
Make up (more dense air is in lower layers )
What occurs
From closest to earth to farthest away
1. Troposphere
Meaning: “Tropo” means turning or changing
a. Depth: 16 km above the equator and thinner at the poles at 9km
i. Shallowest layer
b. Contains dust, water vapor and 75% of all gases
c. Temperature decreases with increasing height
d. Temperature: Every 1km increase in altitude, the air drops 6.5 ˚ C
i. Stops dropping around -60˚C
e. All weather occurs here
2. Stratosphere
Meaning: “Strato” means layer or spread out
a. Depth: extends from Troposphere to 50 km above earth
b. Houses the ozone layer (protection from UV )
c. Temperatures: Lower portion -50 ˚C; upper portion are O˚C
d. Why is the upper portion of the Stratosphere warmer???
e. The Ozone Layer absorbs energy from the sun (heat)
3. Mesosphere
Meaning: “Meso” means middle
a. Depth: begins at 50km above earth and extends to 80-85km
b. Temperature: -90˚C (coldest temps)
c. Protection from foreign objects
d. Trail of hot, glowing gases from the meteor
4. Thermosphere
Meaning: “Thermo” means heat
a. Depth: 80km above earth extending into space
b. Temperature: extremely HOT: 1,800 ˚C
c. Sun strikes this layer first
d. Oxygen and Nitrogen molecules convert energy into heat
e. Air is very thin- 0.001% as dense as air in Troposphere
f. 1 cubic meter of matter at sea level would expand to 100,000 cubic meters
g. Divided into two layers
Ionosphere
Meaning: “Ion” electronically charged particles (sun causes this)
h. Lower layer of Thermosphere
i. Depth: 85km-400km above earth
j. Auroras are caused by particles from the sun that enter the ionosphere near the poles.
These particles strike atoms in the ionosphere—causing them to glow!
Exosphere
Exo” means outer
k. Depth: From 400km for thousands of km
l. Satellites and “space junk” orbit earth here