Station 1: Solar Radiation on Earth

Transcription

1 Station 1: Solar Radiation on Earth Activity Procedures 1. Choose one person to be the Sun. 2. Standing an arm s length away from the globe, have the Sun classmate hold the flashlight level with the equator, and turn it on to shine on the globe. 3. Observe the light hitting the globe and answer the following questions in your journal: Materials globe flash light Does the light hit at different intensities in different locations? Where is the light the strongest? Where on the globe is no light received from the flashlight? 4. While the Sun classmate continues to hold the flashlight in place, have another person slowly turn the globe from west to east, mimicking Earth rotating on its axis. 5. Observe the light hitting the globe and answer the following questions in your journal: Are there still places that receive no light? What location receives the most light? Using the descriptions high, medium, or low, describe how much light the following places on Earth receive when that side of the globe faces the flashlight: Alaska, Antarctica, Ecuador, Greenland, Indonesia, New Zealand, Northern India, South Africa, Southern California, and Sweden

2 Station 1: Solar Radiation on Earth Station Review solar radiation solar radiation 1. Copy the diagram onto a Globe Worksheet. Be sure draw the areas representing the surface area hit by solar radiation. Label the North Pole, South Pole, and the Equator. 2. Answer the following questions in your journal: Look at the arrows in the diagram and notice that the sunlight represented by one band is spread out over a much larger geographic area at the poles than at the equator. How does that affect the amount of energy striking different latitudes? Is the Earth s surface heated by the Sun uniformly? Or unevenly? Explain. Which areas of Earth receive more of the Sun s heat energy per unit area? Why don t these areas simply get warmer and warmer forever?

3 Station 2: Convection Currents Activity Preparation Have students count off and take turns performing the steps in these procedures. Procedures Safety note: This station uses fire and should be performed only with adult supervision. Materials one shoebox with lid plastic wrap heavy-duty aluminum foil two cardboard paper towel tubes or toilet paper rolls, 4-5 in length tape scissors incense sticks one votive candle and glass holder one box of safety matches a bucket of water for emergencies 1. Stand the box on its long side, with the tubes up in the air. Take the window lid off the box. 2. Carefully light the candle and place it inside the box, directly under one of the tubes. 3. Replace the window lid on the box. 4. Carefully light one of the incense sticks and then blow it out so it is smoking. 5. Lower the smoking stick into the tube just above the candle flame (not so close that it catches on fire again). Hold it there for several minutes. Observe the movement of smoke inside and outside the box. 6. Lower the still-smoking stick into the other tube where there is no candle. Lower it several inches into the box, at a similar depth to the candle. Hold it there for several minutes. Observe the movement of smoke inside the box and outside the box. 7. Answer the following questions in your journal: What did you observe the smoke do? What is the pattern of the smoke when the incense stick is held right above the candle? Draw a diagram of this. Draw a diagram of the smoke pattern when the stick is held next to the candle. Where is the air initially the hottest? Define density in your own words. Is hot air more or less dense than cold air? Why? What happens when air becomes less dense? What causes the circular pattern of the smoke? This activity shows convection at work in the smoke Wind in a Box pattern. After what you ve observed, how would you define convection? Convection also happens in the atmosphere. How is convection in the atmosphere different than the convection you did in this investigation? How does atmospheric convection relate to wind, weather, and climate?

4 Station 2: Convection Currents Station Review ascending warm, moist air descending dry, cold air cold dry air ascending warm, moist air descending dry, cold air warm moist air warm moist air descending dry, cold air ascending warm, moist air cold dry air descending dry, cold air ascending warm, moist air 1. If Earth were stationary, Earth s atmosphere would be a very large convection current! Draw this diagram onto a Globe Worksheet. Include the vertical wind patterns from the equator and the poles. Notice how the convection currents are moving warmer and cooler air around the globe. 2. Answer the following questions in your journal: Where is the warmer air coming from? Where is the cooler air coming from? Which temperature of air circulates higher in the atmosphere and which circulates lower? What do you think happens to these giant convection currents on a rotating planet such as ours?

5 Station 3: Earth s Rotation and the Coriolis Effect Activity Procedures 1. Choose a group member to draw the line. 2. Model vertical wind patterns on Earth by drawing a straight line from the equator to the North Pole on the globe. The drawer should establish a steady pace and hold firm with her arm to keep the line straight. Materials globe chalk or dry erase marker safe for use on globe 3. Next, have a different group member rotate the globe slowly from west to east mimicking Earth s natural rotation. 4. While the globe is rotating, model wind patterns on Earth by having the original drawer repeat the vertical line, holding the steady pace and vertical motion amidst the turning globe. 5. Answer the following questions in your journal: What happened to the vertical line when the globe was turning? If the vertical line represents the winds on Earth, what effect does rotation have on the winds? In which direction do the winds turn in the Northern Hemisphere? 6. Now duplicate the activity for the Southern Hemisphere by drawing a straight line from the equator to the South Pole without moving the globe. 7. Now rotate the globe and draw another line in the Southern Hemisphere, again keeping the hand steady amidst the globe s movement. 8. Answer the following questions in your journal: How did the wind direction change in the Southern Hemisphere? Does this direction of wind (originating in the equator) represent cooler air or warmer air movement? 9. Repeat the activity starting the line (winds) at the North and South poles and moving towards the equator on a rotating globe. 10. Answer the following questions in your journal: What happened to these lines on a rotating globe? Does this direction of wind represent cooler air or warmer air movement?

6 Station 3: Earth s Rotation and the Coriolis Effect Station Review N Equator S 1. Study the diagram. As Earth rotates on its axis, its movement affects the winds and the water on Earth. This is called the Coriolis effect. 2. Copy the diagram onto a Globe Worksheet. 3. Answer the following questions in your journal: Does the diagram generally match the lines you drew on the globe during the previous activity? Describe the Coriolis effect in your own words. Can you see any way that the Coriolis effect would create different climates on Earth compared to the non-rotating Earth model?

7 Station 3: Earth s Rotation and the Coriolis Effect Station Review (continued) POLAR EASTERLIES LOW PRESSURE-ASCENDING AIR HIGH PRESSURE-DESCENDING AIR HIGH PRESSURE LOW PRESSURE-ASCENDING AIR WESTERLIES HORSE LATITUDES NORTHEAST TRADE WINDS DOLDRUMS SOUTHEAST TRADE WINDS HIGH PRESSURE-DESCENDING AIR HORSE LATITUDES LOW PRESSURE-ASCENDING AIR WESTERLIES POLAR EASTERLIES 1. Study the diagram. The deflections of air due to the Coriolis effect are cut short by high and low pressure zones in the atmosphere. These zones result in the air either sinking (in high pressure) or rising (in low pressure). 2. Copy the diagram onto a Globe Worksheet. 3. Label the area of low pressure at the equator the Doldrums. 4. Label the area of high pressure at 30 N and S the Horse Latitudes (said to be named so because sailing ships were stranded with no wind in these regions and sailors had to throw horses overboard as they ran out of freshwater to drink.) 5. Find and label the region where you live. Is that an area of high or low pressure? How does that explain the weather in your area?

8 Station 4: Oceanic Surface Currents Activity Procedures 1. Choose one classmate to act as the wind. 2. Have the wind classmate do the following (with the rest of the group observing an taking notes): Blow on the water in the tub from one direction for one second. Materials a long clear plastic tub full of water Blow more forcefully on the water from that same direction for one second. Blow on the water with more force for five seconds. Blow on the water with more force for ten seconds. 3. Answer the following questions in your journal: How are the currents in the water different when you blow on them lightly and more forcefully? How are they different when you blow on them for a short amount of time versus a longer amount of time? How do you think the force and duration of wind drives currents in the ocean? How does the wind create currents in the ocean?

9 Station 4: Oceanic Surface Currents Station Review 1. Study the global wind currents and oceanic surface current diagrams. 2. Copy the surface currents diagram onto a Map Worksheet. 3. Answer the following questions in your journal: How are wind and ocean currents similar? How are they different? How does wind drive oceanic surface currents? What factors besides wind might affect surface currents? Think about the Coriolis effect, placement of landmasses, and seasonal changes when answering this question. How might surface currents affect climate on Earth? Think about global distribution of heat when answering this question. How do surface currents affect our lives? How might surface currents affect our use of the oceans for transportation? POLAR EASTERLIES LOW PRESSURE-ASCENDING AIR HIGH PRESSURE-DESCENDING AIR HIGH PRESSURE LOW PRESSURE-ASCENDING AIR WESTERLIES HORSE LATITUDES NORTHEAST TRADE WINDS DOLDRUMS SOUTHEAST TRADE WINDS HIGH PRESSURE-DESCENDING AIR HORSE LATITUDES LOW PRESSURE-ASCENDING AIR WESTERLIES POLAR EASTERLIES

10 Station 5: Deep Ocean Currents Activity Preparation Have students count off and take turns performing the steps in these procedures. Hot water may be collected from the tap if in the classroom or bathrooms. Materials a long clear plastic storage tub glass jar hot water ice cubes food coloring hot mitts Part A: Procedure (density currents due to differences in temperature) 1. Fill the glass jar with hot water. 2. Add a few ice cubes to the water. 3. Place a few drops of food coloring into the water. 4. All students: Watch what happens. Describe in your journal the motion of the food coloring. What do you see? Why do you think that is happening? Part B: Procedure (density currents due to differences in salinity) 1. Fill the storage tub and the other glass jar with tap water. 2. Add several spoons of salt to the water in the glass jar and mix thoroughly. 3. Add a few drops of food coloring to the salt-water mix. 4. Pour the salt-water mix slowly into the storage tub. 5. All students: Describe in your journal the motion of the food coloring (salt water). What do you see? Why do you think that is happening? 6. Recalling your definition of density in Station 2, answer the following questions about these investigations in your journal: Which has a higher density: hot water or cold water? Which has a higher density: freshwater or salt water?

11 Station 5: Deep Ocean Currents Station Review high salinity water cools and sinks cold deep high salinity current warm shallow current deep water returns to the surface through upwelling 1. Study the diagram: it shows the movement of surface and deep water currents in the ocean around the world. Convection currents in the atmosphere, due to the uneven heating of the Earth s surface, fuel the surface currents. The deep water currents are fueled by density differences in the ocean water in different locations on Earth. This global movement of water is known as the global conveyor belt. 2. Copy the diagram onto a Map Worksheet. 3. Answer the following questions in your journal: Copy your definitions of convection and density from the previous stations. Explain how salinity and temperature affect density. How does salinity affect the global conveyer belt? How does temperature affect the global conveyer belt? Describe the global conveyer belt in your own words. How might the global conveyer belt affect life on Earth?

12 Station 6: Ocean Currents and Life on Earth Final Wrap-up high salinity water cools and sinks cold deep high salinity current warm shallow current deep water returns to the surface through upwelling

13 Station 6: Ocean Currents and Life on Earth Final Questions Answer the following questions in your journal: 1. Study and compare the diagrams again. This time, focus on how the movement of warmer and cooler water might affect climates on Earth. What effect does the global conveyor belt have on Earth s climate? 2. Where do you see a place that warm water is brought close to a continent? Find a country that has cold wind patterns and warm water affecting it. What country is this? What is its climate like? Why do you think this is the case? 3. What area on Earth might be most affected by a change in the global conveyor belt? Make sure to explain why. 4. Describe how you think the following things might be affected by global currents: The movement and clean up strategy of oil spills in the oceans. The path cargo ships take in the oceans to deliver merchandise. Fishermen determining the best locations to find fish. The Coast Guard searching for a person missing at sea. Lifeguards deciding if a beach is safe for swimming. Animal migration in different parts of the oceans.