CH 24.3 Solar Radiation, Pressure,

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CH 24.3 Solar Radiation, Pressure, Wind
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Earths Energy Balance
Surfaces Matter! Albedo measure of how much
solar energy a surface reflects. Ice caps and
clouds have a high albedo. Positive feedback
loops More ice caps --gt more solar energy
reflected --gt cooler --gt more ice caps
Input Suns Energy (Visible light some UV)
REFLECTED 25 by clouds, dust, gases
5 by surfaces
ABSORBED 20 by clouds, dust, gases 50 by
surfaces
Big Idea Most air is NOT heated by the sun
directly.
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Ch. 24.3 Albedo Values Surfaces Matter to
Earths Energy Balance
http//www.the-m-factory.com/portfolio/all_images/
ill_maps-Albedo-Effect.jpg
Question As icecaps melt, how will Earths
albedo change? How will this affect climate?
Why?
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Earths Energy Balance
Output Energy Reflected from Earth back to
space (Usually Infrared - longer wavelength)
Greenhouse Gases CO2, CH4, H2O Allow Visible
light UV to pass through, but Reradiates I.R.
back to surface instead of letting it escape into
space. More GHG more I.R. Warming Temps.
Surfaces reradiate the solar energy that was
absorbed by releasing longer wavelengths of I.R.
(heat) Most of this I.R. escapes into outer
space.
Big Idea The amount of reflective surfaces and
the amount of GHG can have a big impact on TEMPS.
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Feedback Loops

• Positive Feedback a change causes a process to
  continue (amplify response)
• Negative Feedback a change causes a process to
  stop (supression)

• Warming temperatures cause ice caps to melt.
  Discuss how this is a feedback loop
• B. Discuss how Snowball Earth came about through
  positive feedback

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Feedback process that amplifies or suppresses
some initial change.

• Examples
• Positive Feedback
• Ice melts ? Less energy reflected/more absorbed ?
  E. warms ? ice melts

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Ch. 24.3 Energy Transfer in the Atmosphere

• Radiation Energy travels as a wave on the EMS.
• UV Vis. Light from sun absorbed by surfaces
• Infrared (IR) waves are radiated from surfaces
  heat air

2. Conduction Heat energy is transferred by
molecule collisions w/in a few feet of Es
surface. Requires contact b/w molecules.
3. Convection Air masses transfer heat by
moving. Warm, less dense air masses rise
Cooler denser air masses sink ... Convection
Current or Cells. VERY IMPORTANT TO WEATHER
CLIMATE.
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Heat Transfer
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