Earth Science

Atmospheric Processes

Heat Budget of Planet Earth

Study Tip
Like a financial budget, the heat budget accounts for how much comes in and how much is lost or spent.

Where Does Solar Energy Go?

  • About half of the solar radiation that strikes the top of the atmosphere is filtered out before it reaches the ground.
  • This portion of the sun’s radiation can be absorbed, reflected, or scattered before reaching the Earth’s surface.
Study Tip
Like a financial budget, the heat budget accounts for how much comes in and how much is lost or spent.

Heat Budget

  • Despite solar energy constantly entering the atmosphere, the Earth doesn’t grow hotter because the energy escapes into space through the top of the atmosphere.
  • However, the heat budget isn’t balanced because different amounts of solar energy enter the Earth’s different latitudes.

The Amount of Incoming Solar Energy

Region
Day Length
Sun Angle
Solar Radiation
Albedo
Equatorial Region
Nearly the same all year
High
High
Low
Polar Regions
Night 6 month
Low
Low
High
Concept Check
  • What can happen to solar energy entering the Earth’s atmosphere?
  • Why isn’t the Earth’s heat budget balanced?