Energy Pathways

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Energy Pathways
Figure 4.1
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Energy pathways
www.etl.noaa.gov/eo/notes/clouds_and_climate.html
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Energy Pathways through the atmosphere

• Refraction
• Change in speed and direction of light
• Transmission
• Passage of energy through atmosphere or water
• Scattering
• Changing direction of lights movement, without
  altering its wavelengths

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Refraction light travels at different speeds
through different materials
www.mic-d.com/curriculum/lightandcolor/refraction.
html
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Refraction
Figure 4.3
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Refraction

• Sun appears to set 4 minutes after it has
  actually dipped below the horizon.
• The amount of refraction depends on atmospheric,
• Temperature
• Moisture
• Pollutants

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Tansmission

• Some wavelengths of solar radiation are absorbed
  by the atmosphere.

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Scattering why is the sky blue?

• Gas molecules in the atmosphere scatter incoming
  solar radiation.
• The smaller molecules scatter shorter wavelength,
  blue light.

Moonrise
Earthrise
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Insolation Radiation that reaches the Earths
surface.
Figure 4.4
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What affects insolation?

• Latitude further from the equator means less
  insolation.
• Clouds more clouds less insolation

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Albedo - the reflectiveness of a surface
Figure 4.5
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Albedo

• Albedo reflectivity of a surface
• Has values between 0 (no reflectivity) and 100
  (full reflection)
• Albedo values
• Snow 50 95
• Grass 25 30
• Roads 5 10
• Oceans 0 60
• Forests 10 20
• Earth average 31

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Clouds and Albedo
Figure 4.8
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Heat Transfer

• Conduction
• Molecule to molecule transfer
• Convection
• Energy transferred by movement
• Advection
• Horizontally dominant movement
• Radiation
• Energy traveling through air or space

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Heat Transfer
Figure 4.10
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Energy Balance in the Troposphere  

• The Greenhouse Effect and Atmospheric Warming  
• Clouds and Earths Greenhouse  
• EarthAtmosphere Radiation Balance  

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The Greenhouse Effect and Atmospheric Warming

• Atmosphere absorbs heat energy
• A real greenhouse traps heat inside
• Atmosphere delays transfer of heat from Earth
  into space

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Clouds and Earths Greenhouse
Figure 4.11
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EarthAtmosphere Radiation Balance
Figure 4.14
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Energy Balance at Earths Surface

• Daily Radiation Patterns  
• Simplified Surface Energy Balance  
• The Urban Environment

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Daily Radiation Patterns
Figure 4.15
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Energy BalanceRadiated Energy

• Short wave (SW)
• Incoming solar radiation Insolation
• Reflected light
• Long wave (LW)
• Incoming Long wave
• Radiated Long wave outgoing LW

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Global NET R
Figure 4.18
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Latent and sensible heat
Boiling
Water Vapor
100
Water
Temperature (oC)
0
Ice
Melting
Heat added
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Latent head vs. Sensible heat
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Global Latent Heat
Figure 4.19
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Global Sensible Heat
Figure 4.20
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Radiation Budgets
Pitt Meadows, BC
El Mirage, CA
Figure 4.21
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The Urban Environment
Figure 4.22