Energy transfer 15.2

Energy transfer 15.2

• 1.
  CH. 15-2 Energy Transferin the Atmosphere
• 2.
  Energy from theSun  The Sun provides most of the energy on Earth.  Three things happen when Earth receives the energy:  Some is reflected back into space by clouds, atmospheric particles, & Earth’s surface.
• 3.
  Energy from theSun  Some energy is absorbed by the atmosphere  The rest is absorbed by land and water on Earth’s surface.
• 4.
  Energy from theSun  About 35% is reflected back into space.  6% by the atmosphere  4% by Earth’s surface  25% by clouds
• 5.
  Energy from theSun  The other 65% is absorbed.  15% by the atmosphere  50% directly or indirectly by Earth’s surface
• 6.
  Heat  Heat energyflows from warm to cold.  Heat energy is absorbed by roads, rocks, water, & soil.  Heat is transferred through the atmosphere in 3 ways:
• 7.
  Heat  Radiation  Conduction Convection
• 8.
  Radiation  Radiation –Energy from the sun transferred in the form of waves or rays.  You feel the radiation when the Sun warms your face or skin.
• 9.
  Conduction  Conduction –the transfer of energy that occurs when molecules bump into one another.  In other words, one object comes into contact with another….
• 11.
  Conduction  Energy willtravel from the warmer object to the cooler object.  Earth’s surface conducts energy to the atmosphere by air moving over warm land.
• 12.
  Convection  Convection –is the transfer of heat by the flow of material.  Convection circulates heat throughout the atmosphere. How?
• 13.
  Convection  As airis warmed it becomes less dense & rises.  Cooler air moves in to replace the warm air.
• 15.
  Water Cycle  Hydrosphere– all the water on Earth’s surface.  Evaporation – when water changes from a liquid to gas.  Condensation – when water changes from a gas to a liquid.
• 16.
  Water Cycle  Waterevaporates from oceans, lakes & streams AND transpiration from plants  The water vapor (gas) condensates forming clouds.  The water in clouds falls to Earth as precipitation