Composition Nitrogen (N2): 78% Oxygen (O2): 21% Other Gases: 1%

Argon (Ar): 0.934% Carbon Dioxide (CO2): 0.037% Water Vapor (H2O): 0.01 to .04% Neon (Ne): 18.2 ppmv (parts per million by volume) Helium (He): 5.0 ppmv Methane (CH4): 1.8 ppmv Krypton (Kr): 1.1 ppmv Hydrogen (H2): 0.5 ppmv Nitrous Oxide (N2O): 0.5 ppmv Xenon (Xe): 0.09 ppmv Ozone (O3): 0.0 to 0.07 ppmv Nitrogen Dioxide (NO2): 0.02 ppmv

Pressure

Air PressureThe measure of the force with which the air

molecules push on a surface○ The lower the altitude, the higher the

pressure○ The higher the altitude, the lower the

pressure

The Atmosphere Layers

Troposphere 0-16 km from earth’s surface

Top is 10 to 16 km depending on latitude and season. Temp Range:

Highest ever recorded 57.8º C in LibyaColdest ever recorded -89º C in Antartica

Layer right next to the earth’s surface Most dense

90% of atmospheric mass Carbon dioxide, water vapor, clouds, air pollution,

weather, and life forms are found here The top of the troposphere is called the

tropopause.

Stratosphere

From between 10 and 16 to 50 km above Earth’s Surface

Temp Range: -85º C to 0º C Air is very thin and contains little moisture Temperature rises with altitude because of

ozone(O3) Ozone Layer is found in stratosphereOzone absorbs solar energy in the form of

ultraviolet radiation (warms air, protects Earth’s surface)

Mesosphere

50 to 85 km from Earth’s surface Temp Range: 0º C to -90º C Temperature gets colder as altitude

increases Meteors are burned up in this layer

Thermosphere 85 to 500-1000 km above the Earth’s surface Temperature can be up to 2000º C in sunlight! Space Shuttle and ISS (International Space

Station) orbit in this layer What we would think of as “outer space” Temp increases as altitude increases

Absorbs much of Sun’s UV (Ultraviolet) and X-ray energy

Northern Lights (Aurora Borealis) and Southern Lights take place here

Exosphere

From between 500-1,000 to 10,000 km (half the distance to the moon)

No clear boundary between exosphere and space

Molecules stay due to the Earth’s gravitational pull

Molecules so few and far between they hardly collide

TroposphereStratosphere

Mesosphere

Ionosphere

Exosphere

Thermosphere

Write in the Write in the labels!labels!

Ozone layer