1. Heating of the Earth

2. Review of Key Features of the Earth

4. Transfer of Solar Energy
Conduction – energy transferred by direct contact (substance to substance)
Convection – energy transferred by moving (place to place as a gas or liquid)
Radiation – transfer of energy by electromagnetic waves

5. Examples of Conduction
Spoon in a bowl of hot soup
Metal marshmallow stick heating up

6. Conductors Substances that transfer thermal energy quickly and easily.
Iron skillet
Liquids and solids are good conductors because they have freely moving electrons
Coils on stove
Copper pipes
Cookie sheet

7. Insulators Items that transfer energy poorly. Flannel PJ’s Oven Mitt
Plastic spatula
Gases are not good at transferring energy because particles are further apart and have fewer collisions
Ceramic bowl
Fiberglass

8. Examples of Convection
Heated water becomes less dense and rises, boiling water
Hot air expands and is less dense, hot air balloon
Radiator heat

9. Examples of Radiation
ELECTROMAGNETIC SPECTRUM - Spectrum shows the relative wavelengths of each type of radiation

10. Which gets hotter faster? Ocean water or beach sand
Which gets hotter faster? Snow or dirt

11. Absorption & Reflection of Solar Energy
What is effective at absorbing heat?

12. Which heats up faster, land or water?

13. Land Heats Up Faster Because…
Solar energy only penetrates a few centimeters in soil, but up to 300 meters in water
water has a much higher specific heat than rocks or soil.
Convection currents in water moves the heat around

14. Specific Heat
The amount of heat energy it takes to raise the temperature of 1 gram of a substance by 1 degree Celsius
Low specific heat = heats up and cools off quickly (doesn’t take a lot of energy)
High specific heat = heats up and cools off slowly (takes a lot of energy)

15. Greenhouse Effect Energy enters the atmosphere heating Earth’s surface
Surface re-radiates the heat
Greenhouse gases absorb this heat (infrared)
Main greenhouse gases
Carbon dioxide
Water vapor

17. Is the Greenhouse Effect Good or Bad?
GOOD - It is needed for life; it keeps our climate stable and warm.
BAD - too many greenhouse gases causes climate to warm to much

18. Heat Transfer Quiz: Identify the type of Heat TransferC B A
A = Radiation
B = Convection
C = Conduction

19. Heating of the Earth Does the sun heat the earth evenly?
No, its shape does not allow all places on the surface to receive the same amount of energy.
Which area of the earth receives the most solar energy (heat)?
Equator (most direct sunlight)
Which area of the earth receives the least solar energy?
The poles (least direct sunlight)

20. Heating of the Earth

21. Temperature & Air Pressure
Uneven heating of Earth creates different air pressures (highs and lows).
Air Pressure – Created by the number of air molecules moving and bouncing off an object.
Measured using a barometer. Air pressure increases, mercury in tube increases.
Examples:
Warm air = more active air molecules = low air pressure
Ex: equator
Cool air = less active air molecules = high air pressure
Ex: poles

22. Air Pressure – Created by the number of air molecules moving and bouncing off an object. (Measured using a barometer.)

23. Elevation & Air Pressure

24. High and Low Air Pressure Systems

25. Air Pressure & Moisture
Low air pressure usually means warm humid weather (ex: equator). Why?
Warm air causes more evaporation; air molecules are more active & can hold more moisture
High air pressure usually means cooler drier weather. Why?
Less evaporation; molecules are close together holding less moisture.

26. Low Pressure at Equator

27. Differences in Temperature & Air Pressure
Remember: uneven heating of the Earth creates differences in air pressure.
What do the differences in temperature and air pressure create?
Wind
How do they create wind?
Air wants to move from an area of high pressure to an area of low pressure

28. Wind Direction

29. Sea & Land Breeze Convection Currents

30. Sea Breezes Coastal Areas
Land surface heats up fast during the daylight hours
Hot air rises
Creates low pressure
Wind blows from the sea to the land

31. Land Breezes Coastal Areas
Land surface cools off fast during the night hours
Cool air sinks
Creates high pressure
Wind blows from the land to the sea

33. Global Winds
The uneven heating of the earth creating differences in air pressure creates global winds.
At the poles: indirect solar energy; cold temps; high pressure
air sinks and moves towards the equator.
At the equator: direct solar energy; warm temps; low pressure
air rises and moves towards the poles.
The circular movement is called a convection current.

35. Complex Movement of Global Winds
Why isn’t it as simple as one global wind convection current in each the northern & southern hemisphere?
Earth’s rotation affects wind direction.
The influence of the Earth’s rotation on the movement of air and water is called the Coriolis Effect.
The Coriolis Effect cause global winds to turn:
Northern Hemisphere = clockwise
Southern Hemisphere = counter clockwise

36. Coriolis Effect

40. Global Wind Belts & Calm Regions