The Atmosphere
National Weather Service Shreveport
www.srh.noaa.gov/shv
Transfer of Heat Energy
1.Radiation
2.Conduction
3.Convection
Radiation
•The transfer of heat energy by electromagnetic radiation.
•Earth is heated by this process.
- various substances on earth (dirt, rocks, water,
concrete, sand, etc.) absorb this energy and their heat level is
raised. They transmit that heat through mainly convective heat
transfer to the surrounding atmosphere, and eventually to us.
Conduction
• The transfer of heat energy from one substance to
another or within a substance.
• Very effective in heating metals
• Air is a poor conductor.
Convection
• The transfer of heat energy in a fluid.
• Commonly seen in the kitchen when you see boiling water
• Air in the atmosphere acts a fluid
Earth-Atmosphere Energy Balance
The Greenhouse Effect on Earth
Earth’s atmosphere is slightly warmer
than what it should be due to direct
solar heating because of a mild case of
greenhouse effect…
• The ground is heated by visible
and (some) infrared light from the
Sun.
• The heated surface emits infrared
light.
• The majority of Earth’s
atmosphere (N2 and O2) are not
good greenhouse gas.
• The small amount of greenhouse
gases (H2O, CO2) traps (absorb
and re-emit) the infrared radiation,
increasing the temperature of the
atmosphere…
Click on image to start animation
Greenhouse Gases
The most important greenhouse gases are:
– H2O – Water vapor.
– CO2 – Carbon Dioxide
– CH4 – methane
The most abundant greenhouse gas in Earth’s
atmosphere is water vapor. Most of the greenhouse
heating of Earth’s atmosphere is due to Water vapor
absorption of IR radiation emitted by Earth, and then
transferring the energy to the surrounding air
molecule
The Effects of Clouds
• Nighttime: clouds keep the earth warmer
• Daytime: clouds keep the earth cooler
Questions
A sunburn is caused by which method of
heat transfer:
A.) Radiation
B.) Convection
C.) Conduction
D.) Visible Light
Questions
The layer of the atmosphere where most of the
world’s weather occurs is:
A.) Thermosphere
B.) Stratosphere
C.) Troposphere
D.) Hemisphere
E.) Mesosphere
Questions
At night, temperatures will normally be
cooler under cloudy skies than under clear
skies.
A.) True
B.) False
Questions
The brief cloud that forms when you exhale on
a cold winter day was formed because of:
A.) Precipitation
B.) Convection
C.) Evaporation
D.) Condensation
E.) Runoff
Questions
If you feel the heat in the handle of a
cooking pot, that heat was transferred to
the handle by:
A.) Convection
B.) Conduction
C.) Radiation