Ecology. What is the role of the Sun s Energy in Earth s spheres?

Transcription

1 Ecology What is the role of the Sun s Energy in Earth s spheres? videos/ climate-change-bill-nye-news

2 Solar Energy that reaches Earth is absorbed and reflected by Earth s atmosphere and Earth s surface How is a greenhouse similar to Earth s atmosphere? (p , ) Sketch a diagram to show how a greenhouse works. Then relate it to Earth s atmosphere.

3 Earth is a closed system. A greenhouse is a closed system that absorbs thermal energy. The Earth s natural greenhouse effect allows a narrow range of temperatures. Solar radiation comes in, most is absorbed by water, and is then emitted as thermal radiation. This thermal radiation becomes trapped. Greenhouse gases in the atmosphere absorb thermal energy. This keeps Earth an average of 34ºC warmer than it would be otherwise. More greenhouse gases could make it too warm. The main Natural Greenhouse Gases are water vapour, carbon dioxide, methane and nitrous oxide.

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5 Q: What are some natural and human sources of these gases? (page may help you) Q: Predict what would happen to Earth s other spheres if the concentration of greenhouse gases in the atmosphere increased. Handout Reading Check: pg. 487 #1-5

6 Solar energy heats Earth s surface unevenly, and global winds help redistribute thermal energy around Earth (p ) Bill Nye video Almost all of the thermal energy on Earth comes from the Sun. Yet, this is only a small fraction of the solar radiation that reaches Earth. Most thermal energy is transferred near the equator, which receives a more direct source of solar radiation. Solar radiation does not heat the atmosphere directly. Earth s surface absorbs solar radiation, heats up, then radiates the thermal energy into the atmosphere. Convection currents in the air spread the thermal energy around. Angle of incidence

7 Solar energy heats Earth s surface unevenly, and global winds help redistribute thermal energy around Earth (p ) Wind is the movement of air from higher pressure to lower pressure. An air mass is a large body of air with similar temperature and humidity throughout. Air masses can be as large as an entire province or even larger. High pressure systems form when an air mass cools. This usually occurs over cold water or land. Winds blow clockwise around the centre of the system. Low pressure systems form when an air mass warms. This usually occurs over warm water or land. Winds blow counterclockwise around the centre of the system. Lows usually bring wet weather. High pressure system Low pressure system

8 Prevailing Winds Prevailing winds are winds that are typical for a location. Winds in British Columbia usually blow in from the ocean. Precipitation falls as air is forced up the mountain slopes. Air gets drier as it moves inland, continuing to drop precipitation. Dry air rushes down the far side of the mountains into the prairies. The prevailing winds off British Columbia s coast, crossing into Alberta.

9 The Coriolis Effect We know winds move from higher pressure to lower pressure. In a simple model, air would warm in the tropics and rise. Cooler air from the north would rush in below to fill the empty spot. The warm air at higher altitudes would move north to replace the cooler air. This occurs at several latitudes as we move north. As Earth rotates, these winds are bent clockwise = Coriolis effect The equator moves much more quickly than do the poles. Global wind systems develop. (p.450) The trade winds The prevailing westerlies The polar easterlies Wind systems of the world.

10 Q: Summarize why Earth receives more direct energy at lower latitudes than at higher latitudes. Q: Write a summary about how the global wind systems move thermal energy around Earth. Handout Pg. 451#1-5 Pg. 459 #6,7,8 Pg. 461 #18

11 Ocean Currents rents/the-role-of-ocean-currents-in-climate/#.wri66gnysqm

12 Ocean Currents redistribute thermal energy around Earth (p ) Convection currents in the oceans move large amounts of thermal energy all around Earth. Deep ocean currents (200 m and deeper) flow based on density differences. Salinity of water also changes density. Cold water (found at the poles) is more dense than warm water. Salty water (found at the poles) is more dense than fresh water. Large changes in ocean water density can reverse current direction. Deep-ocean currents move cold, salty water below the surface and warm, less-salty water near the surface.

13 Ocean Currents (continued) Surface currents (0-200 m) are warmed by from solar radiation. The thermocline is the region separating surface and deep ocean currents. Upwelling occurs when cold, deep water rises into surface currents. La Niña is an example of upwelling. When this occurs, cool water at the surface of the Pacific Ocean causes warm winters in southeastern North America, and cool winters in the northwest. El Niño is the reverse: warmer water on the surface of the Pacific Ocean results in warm winters in the Pacific Northwest and in eastern Canada. There are 5 major sets of surface currents: north and south Pacific basin, north and south Atlantic basin, Indian ocean basin.

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15 Q:Describe how surface currents in ocean basins redistribute heat between the equator and the poles. Q: How does the great ocean conveyor belt move heat and nutrients around earth? Complete Handout: the oceans currents

16 Solar radiation provides energy for life on earth Solar energy enters the biosphere through photosynthesis and cellular respiration Use page or any other resources to answer the following and compare photosynthesis and cellular respiration : What is it? Which living things use it? How is energy changed? What substances does it use? What substances does it produce? How can it be represented? Why is it important?

17 Answers

18 Photosynthesis 1. What is it? A series of chemical changes in which green plants capture the Sun s light energy and transform it into chemical energy that is stored in energy-rich food compounds such as sugars. 2. Which living things use it? Green plants and certain kinds of single-celled organisms 3. How is energy changed? Light energy is changed to chemical energy 4. What substances does it use? Carbon dioxide (CO 2 ) Water (H 2 O) 5. What substances does it produce? Glucose (C 6 H 12 O 6 ) Oxygen (O 2 ) 6. How can it be represented? Light energy + Carbon dioxide + water glucose + oxygen Light energy from the Sun + CO 2 + H 2 O C 6 H 12 O 6 + O 2 7. Why is it important? Photosynthesis transforms the Sun s energy into a form that living things can use to survive. Photosynthesis produces the oxygen that most living things need to survive.

19 Cellular Respiration 1. What is it? A series of chemical changes that let living things release the energy stored in energy-rich food compounds such as sugars to fuel all life functions. 2. Which living things use it? Nearly all living things on Earth 3. How is energy changed? Light energy is changed to chemical energy 4. What substances does it use? Glucose (C 6 H 12 O 6 ) Oxygen (O 2 ) 5. What substances does it produce? Carbon dioxide (CO 2 ) Water (H 2 O) 6. How can it be represented? glucose + oxygen Carbon dioxide + water + usable energy C 6 H 12 O 6 + O 2 CO 2 + H 2 O + usable energy 7. Why is it important? Cellular respiration releases the energy that living things use to survive Cellular respiration produces the carbon dioxide that green plants need to carry out photosynthesis