3. atmosphere notes

ATMOSPH

ERE NOTE

S

ATMOSPHERE:

Layer of gases that surround the Earth

COMPOSITION:

78% Nitrogen

21% Oxygen

.9% Argon

.1% Other Gases

ATMOSPHERIC PARTICLES:

• Water Vapor – from evaporation and transpiration, ranges from 1% (dry) to 4% (moist)

• Ozone – O3, absorbs harmful UV radiation, being destroyed by particulates

• Particulates – tiny solid particles such as ash, dust, pollen, microscopic organisms

ATMOSPHERIC PRESSURE:

• The pressure exerted on a surface by the atmosphere

• Decreases as altitude increases• Measured using a barometer

LAYERS OF THE ATMOSPHERE:

a) Troposphere

b) Stratosphere

c) Mesosphere

d) Thermosphere

TROPOSPHERE:

• Closest layer to the Earth• Where the weather is found• Temperature decreases as

altitude increases because its heated by Earth’s surface

STRATOSPHERE:

• Almost all the ozone (including ozone layer) in this layer

• As altitude increases temperature increases because UV rays absorbed by ozone

MESOSPHERE:

• Temperature decreases as altitude increases

• Coldest layer

THERMOSPHERE:

• As altitude increase temperature increases because oxygen and nitrogen atoms absorb solar radiation

RADIATION:

All the energy from the sun travels through space through radiation

Travels at 300,000 km/s

SCATTERING:

The deflection of solar radiation due to clouds, dust, water droplets, and gas particles

Thus sunlight hits the Earth surface from all directions and makes the sky blue

REFLECTION:

When solar radiation reaches the Earth surface it is either absorbed or reflected back into the atmosphere depending on the surface

ABSORPTION:

Absorbed solar radiation is converted into infrared waves (heat) and keeps the Earth warm

GREENHOUSE EFFECT:

The warming of the surface and lower atmosphere of Earth that occurs when carbon dioxide, water vapor, and other gases in the air absorb and re-radiation solar radiation

CONDUCTION:

The transfer of heat through a material through direct contact

Collisions between molecules in the atmosphere transfer heat energy

CONVECTION:

Warm air moves up as cool air sinks due to density differences.