Air energy

1. Air energy Earth Science II (Session 3)

2. Air energy • The air’s energy can be transmitted by three different mechanisms: • Convection • Conduction • Radiation. Ciencias de la Tierra II

3. Convection • Convection: is the transmision of heat by materials that flow such as gases and liquids. Ciencias de la Tierra II

4. Convection • Heat is transferred by the movement of gasses from a higher temperature to a region with a lower temperature. • Convection requires the mobility of the environment and accelerates by means of agitation. Ciencias de la Tierra II

5. The fresh ocean breeze during the day • Why is there a nice breze when you dgo to the beach? • What is happening to the air on the ground versus the air over the ocean? Ciencias de la Tierra II

6. The fresh ocean breeze during the day • On a hot day, the air over the ground heats up faster than the air over the water. • The colder ocean air moves from the ocean to the beach, generating a fresh ocean breeze during the day. • What happens to the flow of air after the sun sets? Ciencias de la Tierra II

7. Ocean breeze at night • After dawn, the ground cools more quickly than the water, the direction of air currents invert, that is to say, the air moves from the beach to the ocean. Ciencias de la Tierra II

8. The process of convection is completed mostly in the atmosphere. • What are some other examples of convection? Ciencias de la Tierra II

9. Ascendening currents • On sunny days, the ground and rocks are heated by the rays of the sun. • The rocks transfer heat to the air that surround them; this hot air rises and is cold air takes its place. • That cold air will eventually heat up. • This process happens over and over again forming ascending currents that can be pretty strong. Ciencias de la Tierra II

10. Ascending Currents • Air plane pilots look for Ascending currents to reach high altitudes and maintain flight for their apparatus. Ciencias de la Tierra II

11. Conduction • Conduction: is the direct transmission of heat from one particule to another. Molecules Solid Material Flow of energy Ciencias de la Tierra II

12. Conduction • Is the mechanism thru which thermal energy transfers without macroscopic movement of the environment that conducts the flow of heat. • Air presents a very low thermic conductivity. • In the air, the heat by conduction is transferred when molecules that form it crash between themselves or with the surface they are exposed to. Ciencias de la Tierra II

13. Radiation • Radiation: is the energy that can be transmitted through an empty space. Ciencias de la Tierra II

14. Radiation • Is the constant flow of energy that comes from the sun (ultraviolet, infrared light, etc.) • Thermal radiation, like light, consists of electrmagnetic waves similar to radio, TV and radar waves. • The transfer of energy by radiation does not need a material means, it travels through space with wave like movements. Ciencias de la Tierra II

15. Class reading • From your textbook… • Science and You: Protecting yourself from the sun. • Page 400 Ciencias de la Tierra II

16. Added Material • Page: Action unit by Ozone • Page: Earth Observatory • Virtual laboratory of the ozone layer • Virtual laboratory of solar radiation • Virtual laboratory of heat radiation • Virtual laboratory of neta radiation Ciencias de la Tierra II

17. Bibliography • DiSpezio, M. et al. (1999). Science Insights: Exploring Earth and Space. first ed. USA: Prentice Hall. Ciencias de la Tierra II