Presentation on theme: "Thermal Energy Transfer"— Presentation transcript:
1 Thermal Energy Transfer in the AtmosphereThermal Energy Transfer
2 What is Thermal Energy Transfer? There are three types of thermal energy transfer:RadiationConductionConvection
3 RadiationHeat transfer by radiation is the transfer of heat through electromagnetic waves.
4 RadiationThere is no direct contact between the substances.
5 Radiant Energy from the sun radiates through empty space to earth.
6 Radiant Energy from the sun consists of : Visible LightUltraviolet Light- has a shorter wavelength than visible light and can cause sunburn and skin cancerInfrared Radiation- has longer wave length than visible light and is felt as heat
7 ENERGY ON EARTHNot all of the sun’s energy reaches the Earth’s Surface.20% of the Sun’s Energy is ABSORBED by gases and particles in the Atmosphere.Ozone, Oxygen & Water Vapor absorb ultraviolet lightWater and carbon dioxide(CO2) absorb infrared light.Earth’s Atmosphere (clouds) and the surface of the Earth REFLECTS about 30% of Sun’s radiationAbout 50% of the Sun’s radiation is absorbed by the Earth's Surface
9 RADIATION BALANCEEarth’s temperature remains stable because of the balance between the amount of radiation coming from the Sun and the amount going out from Earth.Land, trees, and the oceans absorb and emit solar radiation mainly in the form of infrared radiation.
10 THE GREENHOUSE EFFECTGlass allows sunlight into a green house. It prevents infrared radiation from escaping which keeps the greenhouse warm
11 THE GREENHOUSE EFFECTCertain gases, such as CO2, in the atmosphere act like the glass in a greenhouse warming the atmosphere.
12 What is Thermal Energy Transfer? Thermal energy transfer is the movement of heat energy from one substance to another.Heat (energy) always moves from objects with high temperature to objects with lowColdHot
13 What is Thermal Energy Transfer? Heat will continue to move until both substances are the same temperature.WarmWarm
14 What is Thermal Energy Transfer? The greater the difference in temperature between the substances, the faster the heat will transfer.
15 Your Coke becomes cold because the heat from the soda Your Coke becomes cold because the heat from the sodatransfers into the ice, not the other way around.
16 No matter what it feels like, cold does not transfer into your body. What is really happening here?Why do you wear heavy clothes when it’s cold outside?
17 Examples Anti-Examples You touch a black car in the summer and the heat from the car transfers into your hand.A breeze makes you feel cooler because the wind transfers heat away from your body.You feel the cold of a winter day because the cold air transfers into you.Your Coke in a cooler gets cold because the cold from the ice moves into the Coke.
18 ConductionThe transfer of thermal energy by the collisions between particles of matter. (through direct contact).Molecules transfer energy to the molecules next to them.
19 Conduction The molecules do not have to be the same substance.
20 ConductionThermal energy is CONDUCTED from the warm ground to the air above it.
21 cooler air, forming a convection current. As air above the road warms up, it becomes less dense and rises and is replaced bycooler air, forming a convection current.
22 ConvectionHeat transfer by convection is the transfer of thermal energy (heat) through the fluid (liquids and gases) movement of currents.
23 ConvectionWarm fluids rise, cool down, sink, and then are warmed again.
24 The radiator warms the room by warming the The radiator warms the room by warming theair around it. Then the warm air transfers heatto the rest of the room through convection.
25 When water changes from one phase to another, Latent heat is exchanged.
26 This picture illustrates all three type of heat transfer. This picture illustrates all three type of heat transfer.Can you identify them all?