Transferring Thermal Energy

1. Transferring Thermal Energy Earth Science Applications Objectives 4-9

2. Thermal Energy • Thermal Energy: sum of the kinetic and potential energy of all the molecules in an object • Thermal Energy increases as temperature increases • Heat is thermal energy that flows from high temperatures to low temperatures • Earth’s sources of heat: Sun, gravitational contraction, radioactive decay, asteroid/meteorite bombardment

3. How is heat transferred? • Conduction • Radiation • Convection

4. Conduction • Transfer of thermal energy through matter by the direct contact of particles • Ex: • Holding snow/ice in your hand • Holding a cup of coffee • Earth Science: conduction occurs at Earth’s surface as the particles in the atmosphere make direct contact with the ground.

5. Radiation • Transfer of energy by electromagnetic waves • Travel through space regardless of matter being present or not • Ex: • Standing by a fire to warm your hands • Earth Science: Sun heating the Earth

6. Radiation

7. Convection • Transfer of energy by the motion of heated particles in a fluid • Energetic particles move from one spot to another, carrying energy with them • Convection currents are a rising and sinking action • Ex: • Lava Lamp • Earth Science: Convection Currents on Earth (mantle, atmosphere, oceans)

8. Helpful Links • Atmosphere and Ocean Live Data • Ventusky Live Data

9. Global Circulation Video • Overall, the Sun heats the surface of the Earth, and Earth radiates back to space about as much energy as it receives over the course of a year. (300) • Day vs. Night, Poles vs. Tropics  Balancing the budget! (301) • Tropics and other places maintain fairly constant average temps bec heat energy is redistributed around the world. The continual motion of air and water reallocates heat energy among Earth’s surface, oceans, and atmosphere and brings it into balance.

10. Energy Transfer in Oceans: Vertically – • Water Masses (397-8) – sea ice forms, salt ions are left, cold salty water becomes denser and sinks, (H – density current) arctic, salty water migrates toward the equator along the ocean floor • Upwelling (405) – upward motion of ocean water, water originates from the bottom of the ocean and are cold, surface water is displaced by winds and replaced by upwelling deep water, waters are rich in nutrients which support marine life

11. Energy Transfer in Oceans: Horizontally – • Density currents - arctic, salty water migrates toward the equator along the ocean floor, move slowly in deep ocean waters (403) • Surface currents – wind driven and follow wind patterns, relatively salty midlatitude / subtropical water carried into polar regions and become colder and denser and sink (403) • Gyres – closed, circular current systems, five major ones, northern hemisphere = clockwise, southern hemisphere = counterclockwise--Read page 404 and view the figure

12. Salinity Graph

13. Salinity Map Salinity Map

14. Light Absorption

15. Thermocline

16. Thermohaline / Global Conveyer Belt

17. Gyres

18. Energy Transfer in Atmosphere: • Global Wind Systems (305-6) • Wind (282) – air moves in response to density imbalances created by the unequal heating and cooling of Earth’s surface, works like air conditioned building, H  L • Air Masses (303) – large body of air that takes on characteristics of the area over which it forms, cPcTmPmT, air masses move transferring heat from one area to another to establish heat balance

25. FRONTS

26. On a weather map

27. Weather Map Ex