Activity 3.1a Earth's Energy Budget

Part I  Read and Learn

Understanding Waves and Energy

This diagram shows two waves.  A wavelength is the distance from a place on one wave, to the same place on the next wave.

The next diagram shows the difference between long wave and short wave energy

The wavelength of the wave is related to it's energy. The diagram below shows that the Sun emits many kinds of energy in all directions.  Only a  very small part of the Sun's energy strikes the Earth.  The Earth absorbs, reflects, and emits energy.  Compared to the Sun, the Earth emits much cooler energy - longwave radiation - what we call HEAT.  Like the Sun, the Earth emits Energy in all directions.

Here's a diagram showing the energy arriving on Earth and being emitted by the Earth.

The Earth is receiving shortwave radiation (incoming energy from the Sun) and emitting longwave radiation (outgoing).  These energies must be in balance so that the Earth has a stable temperature. 

The radiation budget represents the balance between incoming energy from the Sun and outgoing thermal (longwave) and reflected (shortwave) energy from the Earth.   The Sun emits shortwave radiation, the Earth emits longwave radiation. 
 

Study this diagram of the Earth's energy balance. Your teacher will have a color print for you to look at also.