Chapter 22, Section 2
Standards
Chapter 10, Section 2
4b. Students know the fate of incoming solar radion in terms of reflection,
absorption, and photosynthesis
4c. Students know the different atmospheric gases that absorb the Earth’s
thermal radiation and the mechanism and significance of the greenhouse
effect.
8a. Students know the thermal structure and chemical composition of the
atmosphere.
Objective 1
Explain how radiant energy reaches Earth.
Objective 2
Describe how visible light and infrared energy warm
Earth.
Objective 3
Assessment
Summarize the processes of radiation, conduction,
and convection.
Group Posters, Chapter Test
Review
Daily Bellwork, Science Starters, Standards Practice
Solar Energy
Key Terms: Create a flashcard for each. The words can be
found starting on page 555 or use the glossary. If you finish
early, study your new words!
•
•
•
•
•
Electromagnetic Spectrum
Albedo
Greenhouse effect
Conduction
Convection
Solar Energy
Heat in the atmosphere comes from the
absorption of the sun’s rays by gases in
the atmosphere and indirectly as the
ocean and land surfaces absorb solar
energy and then give off that energy as
Radiation
• Radiation= all forms of energy that travel
through space as wave.
• Visible light is a form of radiation the
human eye can see
• UV rays, x-rays, radio waves are also
radiation
• Electromagnetic Spectrum= all of the
frequencies or wavelengths of
electromagnetic radiation
INTERACTIVE
The Atmosphere and Solar Radiation
• As solar radiation passes through the
atmosphere:
• 30% is reflected back into space
• 20% absorbed by clouds, dust, and gases
• 50% absorbed by Earth’s surface
Scattering
Clouds, dust, water droplets, and gas
molecules in the atmosphere disrupt the
paths of radiation from the sun and
scatter them.
This deflection causes the rays to change
direction and some reflects back to space.
Why is the sky blue??
As light travels through the atmosphere the smaller
wavelengths (Blues) hit small particles of gas and
dust, which then scatter the blue light in all
directions across the sky.
Longer wavelength light (Reds) usually pass straight
through the sky, however when the sun is low in
the sky (sunset), only the reds can get through so
we see only shades of red, not blue.
Demo
Reflection
When solar energy reaches the surface it is
either absorbed or reflected.
The fraction of solar radiation that is
reflected = abledo
Amount of energy absorbed or reflected
depends on color, texture, composition,
volume, mass, etc.
INTERACTIVE
Tell me about the GREENHOUSE
EFFECT
Greenhouse Effect
• The Earth’s atmosphere allows radiation to
pass through but it slows the escape of
energy the radiates from the Earth’s
Surface
• Car example…
• Generally the amount of solar energy that
enters the atmosphere is equal to the
amount that escapes into space
• Human activities may change this balance
(CO2 has increased, which prevents energy
BrainPop GreenHouse Effect
Conduction and Convection
Conduction: Transfer of energy as heat through
direct contact of one object to another
Convection: Movement of matter (liquids and
solids)
due to different densities and temperature
differences, which as a result transfers heat
Cool air sinks, warm air rises
Assessment/INTERACTIVE
Answer # 1 and # 8 on page 560
Solar Energy