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Unit Plan |
Heating the Earth: The Atmosphere and Wind Formation
Christie Chiappetta
Morse School
Cambridge, MA |
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AGI, TERC, and their employees do not warrant the completeness, accuracy, appropriateness,
and/or safety of the procedures, materials, and content contained herein.
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Stage 1: Identify Desired Results |
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Unit Description |
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Before starting this unit, students will have a basic understanding of heat transfer. This unit will allow them to apply their understanding of heat transfer to the atmosphere as they investigate the absorption of the sun's energy and the earth's attempt to balance heat through the movement of air, or winds. The unit will begin by looking at what happens to the sun's energy after it enters the atmosphere and its absorption by the surface of the earth. The second part of the unit will investigate how both global and local winds are generated as this heat is transferred throughout the lower atmosphere. |
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Relationship to the Big Ideas in Earth Science: |
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2. Radiation, conduction, and convection transfer energy through the earth's systems.
9. Radiant energy from the sun creates temperature differences in water, land, and atmosphere which drive local, regional, and global patterns of atmospheric circulation.
10. The atmosphere exhibits long-term circulation patterns and short term patterns known as weather. |
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Unit Enduring Understandings: |
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- Energy from the sun and the Earth's attempt to balance its heat budget are the driving forces behind weather and climate.
- Heat energy is transferred to the atmosphere and throughout the atmosphere through conduction, convection, and radiation.
- Both global and local winds are caused by the unequal heating of the earth's surface.
- The atmosphere is a relatively thin layer of gases that surrounds the Earth.
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Unit Essential Questions: |
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- What would it be like to travel through the atmosphere?
- What causes winds?
- What would the Earth be like if there was no wind?
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What students will need to know and be able to do (knowledge and skills): |
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- The sun's energy is reflected and absorbed by both the atmosphere and the surface of the Earth.
The Earth as a system is constantly trying to balance its heat budget by moving cold air from the poles towards the tropics, and warm air from the tropics towards the poles. - Heat is transferred from the earth's surface to the atmosphere through conduction and radiation.
Once heat is in the atmosphere, convection currents transfer heat as warm air rises and air from high pressure (cool) areas to low pressure (warm) areas. - Because the Earth is a sphere, light hits its surface at different angles. This causes unequal heating of the earth by lattitude.
The properties of different surfaces absorb and reflect light differently.
Global and local winds are caused by the convection currents created due to unequal heating of the earth's surface.
The paths of winds curve because of the earth's shape and rotation.
Because of the Coriolis Effect and difference in air pressure, the earth has major wind belts. - Students will analyze and create maps to represent heating and wind patterns on earth.
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What do students typically misunderstand? |
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The atmosphere is thick compared to the size of the earth.
Weather happens throughout all levels of the atmosphere.
Winds never die down, they just move around to different parts of the earth.
The earth generates its own heat.
The poles of the earth are cold because they are farther from the sun.
Winds are caused by the Earth spinning.
Wind is created by the movement of objects on Earth (trees, waves, rivers, etc.) |
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Stage 2: Determine Acceptable Evidence |
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What is the Goal of the performance? |
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The goal of the assessment is to use the design process to design and build the best solar heater (an oven to melt a chocolate chip or to heat water.) Students will use their lab experiences and understanding of heat transfer on earth and withing the atmosphere to develop the most effective design. |
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What Role does the student assume in the performance? |
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The student assumes the role of a scientist hired by United States Department of Energy to help design a solar heating device. |
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What Audience does the student address? |
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The target audience consists of government officials who will judge whether or not your product works well enough to produce and sell to the public. |
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What is the Situation for the performance? |
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Pollution from the burning of fossil fuels has lead the government to promote the use of solar energy by funding the invention of products that rely on energy from the sun. You have been asked by the U.S Department of Energy to use your understanding of the heating patterns on Earth to design a new product for them.
A Solar Water Heater: The Department of Energy (DOE) is looking for a way to take advantage of the sun’s energy to heat water for homes. They would like you to build a miniature model, the size of a shoe box, that will heat a pipe (plastic tube) filled with water to the highest temperature possible. They will provide some simple, cost effective materials for your use.
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A Solar Cooker: The DOE is also looking for a device that could be used to cook food when there is not a fuel source available. They are open to any type of container for the cooker, it just needs to have dimensions no longer than 30 centimeters in any direction. Your device needs to melt a refrigerated chocolate chip in the shortest amount of time possible.
Your product will have two parts: a product (solar oven or solar heater) and a poster presentation documenting background research, blueprints, and testing data for three prototypes. |
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What Product should be produced? |
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Students will go through the design process to construct a prototype solar oven or water heater. They will then redesign their protype two more times, changing one variable with each redesign.
Throughout the process, students will document their work. This documentation will be put together on a posterboard and presented to the class (board members of the company.) |
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What are the Standards for the product? |
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Throughout the process, you must construct 3 testable prototypes.
Your presentation poster to the board should include the following:
- Background information including the science related to solar energy and its trip to Earth.
- A Blueprint for Prototype #1
- Testing data for Protype #1 including suggestions for improvement
- A Blueprint for Prototype #2
- Testing Data for Prototype #2 including suggestions for improvement
- A Blueprint for Prototype #3
- Testing Data for Prototype #3
- A conclusion summarizing what you have learned from your research and any final suggestions before the product is manufactured. |
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Preconception Survey: |
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1. Imagine a group of light rays traveling towards the earth's surface. Draw what you think might happen to them as they approach the earth. (drawing of Earth with land, water, and clouds labeled)
2. Where do you think the wind we feel in Cambridge is coming from?
3. If the sun did not exist, you could not fly a kite. Why do you think this is true? |
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Quizzes, Tests, and Academic Prompts: |
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Pre-conceptions check
Writing assignment (trip through the atmosphere)
Map analysis prompt (Heat distribution on earth)
Text analysis (absorption and reflection of the sun's rays)
Wind forecast (land/sea breeze formation)
Wind belt prompt (convection currents)
Revisit pre-conceptions |
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Other Evidence: |
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Stage 3: Plan Learning Experiences, Instruction, and Resources |
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Use WHERETO as a guide to describe the learning experiences, instructional strategies, and resources you will use to help students
address the essential questions of the unit and achieve deep understanding of the big ideas. |
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W
Students will start with a preconceptions quiz.
The following questions will be asked:
1.Imagine a group of light rays traveling towards the earth's surface. Draw what you think might happen to them as they approach the earth. (on a blank picture with clouds, land, water, etc.)
2. Where do you think the wind we feel in Cambridge is coming from?
3. If the sun did not exist, you could not fly a kite. Why do you think this is true?
Introduce the essential questions
Briefly describe the final performance assessment.
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Students will start with an activity around the the thickness of the atmosphere. Students will be given an outline of the Earth and asked to draw a line representing the thickness of the atmosphere. The same picture will be on the board and students will share out their ideas. The actual thickness to scale will then be presented.
lesson description and images
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What is the atmosphere like?
Graphing the layers: Students will create a scaled column of the layers of the atmosphere. lesson description and images
A power point presentation will review the basic properties of the atmosphere and show some relevant images (thickness, view from space, layers, and temperature differences.)
Students will write an essay describing what it would be like to take a trip through the atmosphere.
What happens to the sun's energy upon entering the atmosphere?
1.Angle of light affects heating
Students will analyze GLOBE maps of solar energy to get at how angle of light affects the amount of energy certain lattitudes receive.
Globe Maps:
http://archive.globe.gov/sda-bin/wt/ghp/gdp_images+L(en)
There will be a globe and flashlight on hand for additional demostrations.
2. Absorption of light differs by surface properties
A.)Lab: Black Can/Silver Can
Students will perform a lab where the collect temperature data for the heating of a can painted black and silver can. They will try to explain the temperature differences and apply their data to areas of reflection and absorption on earth. This lab will also review conduction, convection and radiation as they apply it to the earth systems.
B.) Students will use GLOBE maps to analyze temperature data throughout the year on earth, with a focus on connecting lab data to observations they make of the maps. Reflection and absorption rates are noticeable, especially at the poles.
(Reflection/Quiz- Look at the July sun energy map and temperature map side by side. What do you notice? How can you explain the differences?)
3. Tying it together- drawing the sun's rays
Students will read about how the sun's energy reaches the earth. They will be given the text with a blank picture of the Earth at the top. Notes will be taken by drawing in the path of the sun's rays as described in the text (Prentice Hall - Weather p.13-14)
(Reflection piece- What is new information for you? Based on what you have learned so far, what would you add to make this a more accurate picture?)
Going to the Beach! Understanding Local Wind
4. Lab: Heating up the Earth
Students will place sand and water under a heat lamp and observe how each substance absorbs and retains heat.
5. Convection Activity: Streamers
Students will add drops of colored hot water into a beaker of cold water and make observations. Colored cold water will then be dropped into hot water and observations will be made.
6. Reflect/Check: Students will be given a picture of beach and ocean during the night and day. Draw in which way you think the air above this area will be moving? Which way does the wind blow? Lay the foundation here that the earth wants to balance its heat budget?
(How well students remember/understand heat transfer and convection will be revealed in this assignment.)
6. Additional Convection lab (if needed)
http://www.ucar.edu/learn/1_1_2_7t.htm
7. Class discussion/readings
Students will walk step by step through what is going on in the land/sea breeze example. Important terms will include high and low pressure and convection.
Visualization:
http://www.intellicast.com/DrDewpoint/wx101/1099Wind/
Text: Prentice Hall Weather p.22-23
(Review/Quiz: Students will be given a map of the U.S. labeled with coastal cities label and their land and sea temperature data. Students will have to determine whether or not their will be a land or sea breeze for each city. Answers will be presented to the class as a weather forecast.)
Looking at the bigger picture: Global Winds
8. Students will revisit the temperature data maps and try to predict what will happen with air/heat across the earth. What is happening at the equator? at the poles? Have a globe and light on hand to demonstrate.(This where the idea of the earth trying to balance its heat budget is discussed.)
Visualization:
http://ess.geology.ufl.edu/ess/Notes/AtmosphericCirculation/simpatmcell_lg.jpeg
http://www.ucar.edu/learn/1_1_1.htm
The teacher will introduce the Coriolis Effect here, explaining that because the of the earth's shape and rotation the wind curve and wind belts are created.
Supporting activity:
http://kids.earth.nasa.gov/archive/nino/wind.html
Visualizations:
http://ess.geology.ufl.edu/ess/Notes/AtmosphericCirculation/atmoscell_big.jpeg
9. Students will read about and map the wind belts.
http://kids.earth.nasa.gov/archive/nino/global.html
Text reading: Prentice Hall Weather pp. 24-27
Students will read/ hear historical and interesting information about the wind belts (trade winds, horse lattitudes, doldrums...)
Clip of South America- application/connection
http://www.jpl.nasa.gov/srtm/images/movies/AndesFlt_3201.MPG
(Review/Quiz: Looking at the diagram of wind belts what is the wind like at the equator? Why? There is a saying that you can be stuck in the doldrums. How is this a true scientific statement?)
How scientists study the wind...
10.If time permits, it would be a great extension to use some real time data activity using Quikscat satellite data to help students understand how scientists get information on winds. Connection to hurricane movement by plotting a hurricane's path using the Event Based Science hurricane text. (visualization?)
http://windss.jpl.nasa.gov/missions/quikscat/quikindex.html
http://haifung.jpl.nasa.gov/anim.html#NWATL
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Small quiz /reflection activities are included throughout the unit. Detailed descriptions are included in the experience section above.
End of Unit Prompt: What would the earth be like if there were no wind?
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Students will use thir understanding of how temperature differences are created on Earth to design a solar oven or solar water heater.
Students will also take a post-conceptions quiz and then look back on their pre-conceptions answers. Students will evaluate their own learning in a reflection piece. |
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