Atmospheric Heating Chapter 15 section 2

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Atmospheric HeatingChapter 15 section 2
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Objectives

• Describe what happens to solar energy that
  reaches the Earth.
• Summarize the processes of radiation, thermal
  conduction, and convection.
• Explain the relationship between the greenhouse
  effect and global warming.

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The Earth and its atmosphere are warmed by the
energy radiating from the sun.

• It takes a little over 8 minutes for the energy
  to reach your face from 149,000,000km away!

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Heat!
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Energy from the sun is called Radiation

• Radiation- transfer of energy as
  electromagnetic waves.
• The Earth receives only about two- billionths of
  the total suns energy.
• This radiant energy drives the weather cycle and
  makes the earth inhabitable.

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Energy from the sun is absorbed by the
atmosphere, land, and water and is changed into
thermal energy.

• 25 - scattered and reflected by the clouds and
  air.
• 5 - reflected by the Earths surface.
• 50 - absorbed by Earths surface.
• 5 - reflected by Earths surface.

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Conduction Energy Transfer by Contact

• Thermal Conduction- transfer of thermal energy
  through a material.
• Always moves from warm to cold areas.
• When air come in direct contact with the warm
  surface, thermal energy is transferred to the
  atmosphere

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Conduction
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Convection Energy Transfer by Circulation

• Convection- the transfer of thermal energy by the
  circulation or movement liquid or gas. Due to
  differences in Density!
• convection currents are created as warm air rises
  and cool air sinks.

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Convection
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The Greenhouse Effect and Life on Earth
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The Greenhouse Effect and Life on Earth

• Greenhouse Effect gases in the atmosphere (H2O
  and CO2) absorb thermal energy and radiate it
  back to Earth.
• This process functions like the glass of a
  greenhouse, allowing solar energy to enter but
  preventing it from escaping.

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The Radiation Balance

• For Earth to remain livable, the amount of energy
  received from the sun and the amount of energy
  returned to space must approximately equal.
• Energy In Energy Out
• Is it balancing out?!?!?

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Global Warming

• The gradual increase in average global
  temperatures
• Data shows that the average global temperatures
  have increased in the past 100 years.
• Scientists hypothesize that greenhouse gases may
  be the cause.
• What would the effects be of the Greenhouse
  Effect on the Earth as we know it?