1. Heat Transfer, Greenhouse Effect, Ozone Layer Notes

2. How does the Earth get heated?
Energy transfer from the sun

3. Energy The ability to do work or cause change Temperature Gas
The average amount of energy of motion of each molecule (the measure of how hot or cold something is)
Gas
Moving particles, the hotter they get the faster they move

4. The atmosphere moves energy
Energy moves by heat transfer
There are 3 types of heat transfer
Conduction
Convection
Radiation

5. Conduction
The transfer of heat energy from one substance to another through DIRECT contact
The Earth’s surface heats the air (gas) molecules directing above it
Molecules of air gain energy when they collide with the molecules in grains of hot sand.

6. Convection
Transfer of energy from place to place by the motion of gas or liquid (fluids)
Up and down movement of molecules not the side to side movement

7. Density and Convection
The atmosphere gets less dense at higher altitudes
Warm air is less dense than cold air
Warm air has more energy, so molecules move faster than cold ones
This makes them collide more, then they spread out
More space between molecules = less dense

8. Radiation The transfer of the Sun’s energy to the Earth’s surface
Solar radiation heats both the surface and the air
Includes visible light
Earth’s surface gives off a type of invisible radiation called Infrared radiation

9. Earth’s absorption of Radiation
30% of incoming solar energy is reflected by clouds
70% is absorbed and becomes different forms of energy
Absorbed by oceans, landforms, and living things (photosynthesis and respiration)
This absorbed energy heats the Earth’s surface

10. Transfer of Energy

11. Gases Absorb and Give Off Radiation
The Atmosphere affects light in 4 ways.
Absorbs Light
Reflects Light
Lets Light Pass Through
Emits (Gives Off) Light
On sunny days more visible light gets to the earths surface.
On cloudy days clouds reflect and absorb most of the sunlight

12. Forms of Radiation We Cant See
Ultraviolet Radiation
More energy than the light you can see
Can cause sunburns and other damage
Infrared Radiation
Less energy than the light you can see
Warms the materials that absorb it

13. Ozone Layer Protects Life
Ozone - O3
Ozone in stratosphere is called the ozone layer
Protects life on Earth
Absorbs harmful ultraviolet radiation from sun
Too much can cause sunburn, skin cancer, and can harm crops, plastic or paint
Lets other types of radiation like visible light through

15. Greenhouse Effect Animation Keeps Earth Warm
Slow the movement of energy away from the Earth’s surface
Greenhouse gases
Includes carbon dioxide, methane, water vapor, and nitrous oxide
Gases mix with gases in the air like nitrogen and oxygen. Not its own layer
Found in the troposphere
Absorbs and emits infrared radiation
Animation