1. Earth’s Energy Budget

2. Modes of Energy Travel Heat Energy can be transferred in three specific ways: Heat Energy can be transferred in three specific ways: Conduction Conduction Convection Convection Radiation Radiation

3. Heat Transfer Conduction - atoms that are energized (heated) collide with other atoms that are not energized and give them some of their energy Conduction - atoms that are energized (heated) collide with other atoms that are not energized and give them some of their energy Convection – atoms that are energized move from one place to another Convection – atoms that are energized move from one place to another Radiation – atoms emit electromagnetic waves. This is how sunlight gets to earth. Radiation – atoms emit electromagnetic waves. This is how sunlight gets to earth.

4. Solar Energy When radiant solar energy reaches the Earth, 2 different interactions occur: When radiant solar energy reaches the Earth, 2 different interactions occur: Reflection – the radiation is reflected back into space unchanged Reflection – the radiation is reflected back into space unchanged Absorption – the radiation is absorbed by the atmosphere of the Earth’s surface. Absorption – the radiation is absorbed by the atmosphere of the Earth’s surface. 70% absorbed 70% absorbed 30% reflected 30% reflected

5. Breakdown

6. Earth’s “Constant” Temperature The Earth retains a relatively constant temperature. The Earth retains a relatively constant temperature. To do this, it must lose as much energy back to space as it absorbs from the Sun. To do this, it must lose as much energy back to space as it absorbs from the Sun.

8. Energy and Water Most of the sun’s energy hits water on earth (earth is 70% water) Most of the sun’s energy hits water on earth (earth is 70% water) Interactions between the sun’s energy and water have a major influence on weather but it depends on what state the water is in Interactions between the sun’s energy and water have a major influence on weather but it depends on what state the water is in White snow reflects up to 90% of the incoming solar energy White snow reflects up to 90% of the incoming solar energy Ice reflects about 50% Ice reflects about 50%

9. Energy and Water Liquid water reflects only about 7% (i.e. it absorbs about 93%!!!) Liquid water reflects only about 7% (i.e. it absorbs about 93%!!!) Therefore many weather systems are initiated from the energy that is absorbed by the oceans Therefore many weather systems are initiated from the energy that is absorbed by the oceans

10. Water in the Air Water exists in the air as a gas (water vapour) Water exists in the air as a gas (water vapour) When the air becomes saturated, condensation of the water vapour occurs (forms liquid water droplets) When the air becomes saturated, condensation of the water vapour occurs (forms liquid water droplets) The amount of water vapour in the air is measured by humidity The amount of water vapour in the air is measured by humidity

11. The Water Cycle The incoming sun causes ~23% of liquid water to evaporate The incoming sun causes ~23% of liquid water to evaporate Evaporation occurs from all bodies of water but mostly the oceans Evaporation occurs from all bodies of water but mostly the oceans Evaporation occurs from plants through their leaves through a process called transpiration (or evapotranspiration) Evaporation occurs from plants through their leaves through a process called transpiration (or evapotranspiration)

12. The Water Cycle Movement of air saturated with water vapour into cooler areas causes condensation and formation of clouds Movement of air saturated with water vapour into cooler areas causes condensation and formation of clouds When moisture falls to the ground as precipitation When moisture falls to the ground as precipitation if there is enough precipitation, it can run off from the ground into lakes, rivers and oceans as surface runoff if there is enough precipitation, it can run off from the ground into lakes, rivers and oceans as surface runoff

13. The Water Cycle If the water does not runoff, it can be absorbed into the earth as groundwater If the water does not runoff, it can be absorbed into the earth as groundwater If there is enough groundwater, the water will flow back to the waters on the surface as groundwater flow If there is enough groundwater, the water will flow back to the waters on the surface as groundwater flow

14. Assignment Using your notes that you just copied, draw your own picture that shows the water cycle. Include the following terms: Using your notes that you just copied, draw your own picture that shows the water cycle. Include the following terms: Evaporation Evaporation Transpiration Transpiration Condensation Condensation Surface Runoff Surface Runoff Groundwater flow Groundwater flow Precipitation Precipitation

16. Heating the Dry Land Why is it that when you are at the beach, the sand can be scorching hot while the water is cool? Why is it that when you are at the beach, the sand can be scorching hot while the water is cool? After all they are getting the same amount of solar radiation After all they are getting the same amount of solar radiation

17. Heating Dry Land Water is cooler because it has a higher specific heat capacity – meaning that it can absorb much more heat than dry land Water is cooler because it has a higher specific heat capacity – meaning that it can absorb much more heat than dry land All sunlight that hits the sand or earth is absorbed in the top few cm making it 5 times as hot as water All sunlight that hits the sand or earth is absorbed in the top few cm making it 5 times as hot as water All sunlight that hits water can be absorbed in layers much deeper thus making it cooler All sunlight that hits water can be absorbed in layers much deeper thus making it cooler

18. Heating the Air The first step is conduction The first step is conduction Conduction heats the air by hot (energized) water and land molecules transferring their heat (energy) to the surrounding air Conduction heats the air by hot (energized) water and land molecules transferring their heat (energy) to the surrounding air The air directly above the land or water then becomes a similar temperature to the temperature of the water or land The air directly above the land or water then becomes a similar temperature to the temperature of the water or land

19. Heating the Air The second step is convection The second step is convection As the lower layers of air warm, it expands becoming less dense As the lower layers of air warm, it expands becoming less dense Since it is less dense and warm, it rises and cooler air takes the place closer to the ground Since it is less dense and warm, it rises and cooler air takes the place closer to the ground Other substances in the air such as CO 2 and H 2 O (g) can absorb sunlight and can cause temperature in the air to fluctuate Other substances in the air such as CO 2 and H 2 O (g) can absorb sunlight and can cause temperature in the air to fluctuate

20. Heating the Air Uneven heating of the air causes wind Uneven heating of the air causes wind When cold air is located near warm air it pushes it upwards and creates wind When cold air is located near warm air it pushes it upwards and creates wind

21. The Atmosphere The layer closest to the earth in which all heat, air and water interactions occur (weather) occurs in the troposphere. The layer closest to the earth in which all heat, air and water interactions occur (weather) occurs in the troposphere. The troposphere extends about 10 km from the surface of the earth. The troposphere extends about 10 km from the surface of the earth. At about 11 km the temperature starts to cool off to -57ºC At about 11 km the temperature starts to cool off to -57ºC

22. The Atmosphere As the altitude increases the temperature starts to warm again. As the altitude increases the temperature starts to warm again. From 11 km to 50 km is the region called the stratosphere From 11 km to 50 km is the region called the stratosphere This layer also known as the ozone layer This layer also known as the ozone layer The ozone layer absorbs huge amount of ultraviolet radiation The ozone layer absorbs huge amount of ultraviolet radiation This prevents living creatures on earth from getting crispy This prevents living creatures on earth from getting crispy

23. The Atmosphere At about 60 km from the earth’s surface is the mesosphere At about 60 km from the earth’s surface is the mesosphere Temperature starts to decrease here Temperature starts to decrease here At the top of the mesosphere (90 – 100 km above earth) the temperature is about -90 to -100 ºC At the top of the mesosphere (90 – 100 km above earth) the temperature is about -90 to -100 ºC All layers above the troposphere exert pressure on the layers below. We know this as atmospheric pressure. All layers above the troposphere exert pressure on the layers below. We know this as atmospheric pressure.

24. The Atmosphere Standard atmospheric pressure at 25 ºC is 101.3 kPa Standard atmospheric pressure at 25 ºC is 101.3 kPa Temperature differences causes small differences in the local pressure systems Temperature differences causes small differences in the local pressure systems

25. The Atmosphere Draw a picture that shows a slice of the earth and the layers of the atmosphere with their distances. Draw a picture that shows a slice of the earth and the layers of the atmosphere with their distances.