1. C HAPTER 2; S ECTION 2 A TMOSPHERIC H EATING Heat transfer

2. THINK ABOUT IT… If you add ice to lemonade on a hot summer’s day why does the ice melt? Choose the best answer: A. The coldness from the ice moved into the lemonade B. The heat from the lemonade moved into the ice C. The coldness and heat moved back and forth until the lemonade cooled off

3. The correct answer is B. The heat from the lemonade moved into the ice. Heat energy is transferred from one place to another through the process of heat flow. This thermal energy will only move from a warmer object to a cooler object, never the other way around. Heat went into the ice from the lemonade, cooling the lemonade and melting the ice

4. H EAT CAN BE TRANSFERRED IN 3 WAYS :

5. R ADIATION : S OLAR E NERGY T RANSFERS BY W AVES Radiation: is energy that is transferred as electromagnetic waves, such as visible light and infrared waves. (Energy transferred from the sun in waves) The Sun heats up the Earth through radiation Examples include visible light, radio waves, sunlight,and radiant heat. Can be in the form of particles or waves.

6. E XAMPLES OF RADIATION ( HEAT )

7. C ONVECTION The transfer of heat by a liquid or gas (such as air). A convection current is where hot less dense air rises and cold more dense air sinks. Convection causes most of the heating of the troposphere (atmosphere)

8. E XAMPLES OF CONVECTION

9. C ONDUCTION : S OLAR E NERGY T RANSFERS BY C ONTACT The direct transfer of heat from one substance to another substance that is touching it. Conduction works better in certain substances, like metals

10. E XAMPLES OF CONDUCTION

11. A LL 3 TYPES WORK TOGETHER :

12. H EATING IN THE TROPOSPHERE Convection causes most of the heating of the troposphere Air near the ground is heated by the sun (radiation) The molecules gain energy and move faster As they bump into each other they move further apart and become less dense The less dense air then rises due to the warm temperature Cooler, denser air sinks This causes a constant movement of heat through the troposphere called convection current !!

13. R ADIATION Direct transfer of energy without heating the space in between Fireplace Microwave Radiator Energy from the Sun to the Earth

14. C ONVECTION Transfer of a heat through a fluid (gas or liquid) Oven Boiling Water Air rising (hot) and falling (cold

15. C ONDUCTION Transfer of heat from one substance to another that is touching Hair Straightener Heating Pad Electric Blanket Energy from molecules that touch Earth’s surface