March 19, 2013 Earth Science Strand Focus: Earth Science Standard 4 By Rich Hedman and Ingrid Salim

Goals for Workshop Two main goals: To develop in each of you an understanding of the science content. To encourage each of you to use a student-centered and data-centered instructional approach.

Instead of the more traditional teacher-centered approach. Not much of this in this workshop

However, the instructional approach is highly teacher-guided.

Instead of telling you about the greenhouse effect, we will present you with data and questions from which you can construct your own understanding. We want you to figure it out for yourself. We will be here to help guide you. We may do some telling if necessary. We encourage you to take the same approach with your students. This student- and data-centered instructional approach is aligned with how people learn science and how scientists engage in their work.

Rules of Engagement Be considerate and respectful in language and tone. Make sure everyone has a chance to express their ideas. Try to not steal anyone’s “Aha!” moment by “telling” them your “answers”—instead ask questions that will guide your group to these ideas. (ask, don’t tell!)

The Science Part One: Earth and the Moon Temperatures Part Two: Consider a New Phenomena (lab) Part Three: Create a Model Part Four: More Data Part Five: Apply Our Model to Other Planets

Data: Earth / Moon Temperatures You will be given temperature data from the Apollo 17 landing site (Taurus-Littrow region) You will also be given temperature data for a typical week in Sacramento in May.

Phenomena: Earth / Moon Temperatures Question: What similarities, differences, and patterns do you notice in the data on the earth and moon temperatures? Work with your group to list some of your observations on the whiteboard. Be prepared to share an observation or two. We will capture your observations on chart paper.

Consider a New Phenomena Before we try to explain the patterns you found in the earth/moon temperature data, first we want you to consider a new phenomena. You will be given a box with 2 sections, one covered in plastic wrap, the other uncovered. You will have two thermometers and a light source. Use the data table provided to record temperatures. Record initial temperatures before turning on the light. Record temperatures for 10 minutes, then turn off the light for the final 10 minutes of data.

Consensus on Box Temperature Phenomena Describe your results. We will capture your ideas. Do we all agree?

Model: Temperature in Boxes A model is a coherent set of ideas. What set of ideas could explain the temperature differences you described between the covered and uncovered sections of the box? With your group, write down a list of statements and a diagram which can be used to explain the temperature differences you observed. Be prepared to share your model. We will capture the model on chart paper.

Summary of Box Temperature Models Do we have consensus on one model, or do we have multiple models that can be used to explain the temperature phenomena? If possible, reach consensus by combining ideas. If consensus isn’t possible, we will keep multiple models “alive” until we get more data. Ok—now let’s go back to our original question…

Earth / Moon Temperatures Review the patterns observed in the data.

New Data to Consider Earth has an atmosphere. What happens when light enters earth’s atmosphere?

The Atmosphere and Incoming Sunlight

Model: Earth / Moon Temperatures A model is a coherent set of ideas. What set of ideas could explain the temperature differences you described between the earth and the moon? With your group, write down a list of statements and a diagram which can be used to explain the temperature differences you observed. Be prepared to share your model. We will capture the model on chart paper.

Summary of Earth/Moon Temperature Models Do we have consensus on one model, or do we have multiple models that can be used to explain the temperature phenomena? If possible, reach consensus by combining ideas. If consensus isn’t possible, we will keep multiple models “alive” until we get more data. Ok—let’s consider additional data…

Possible Consensus Model of Greenhouse Effect on Earth

Earth’s Atmosphere Composition of earth’s atmosphere. Which gases are considered “greenhouse gases”? Why are they considered greenhouse gases? (show their specific heat capacities, show how they absorb certain wavelengths of light).

Carbon dioxide () is one of the greenhouse gases. It consists of one carbon atom with an oxygen atom bonded to each side. When its atoms are bonded tightly together, the carbon dioxide molecule can absorb infrared radiation and the molecule starts to vibrate. Eventually, the vibrating molecule will emit the radiation again, and it will likely be absorbed by yet another greenhouse gas molecule. This absorption-emission-absorption cycle serves to keep the heat near the surface, effectively insulating the surface from the cold of space.

What about other planets? Now that we have an understanding of the greenhouse effect on earth, and the role of the different gases in our atmosphere, let’s consider other planets. Look at the data table on the inner planets.

Apply our Greenhouse Effect Model Pick a planet (not earth), and use our model of the greenhouse effect to explain the temperatures on the planet. Use diagrams and text. Be prepared to share your ideas. If you finish one planet, pick another!

Apply our Greenhouse Effect Model Ok, let’s share our ideas!

From: bouman.chem.georgetown.edu Comparison of Atmospheres: Venus, Earth, Mars

Atmosphere of Venus (from Venus Express spacecraft) From: Svedhem, H., Titov, D.V., Taylor, F.W., Witasse, O. (2007). Venus as a more earth-like planet. Nature, 450, 29 November 2007.

Summary of Earth, Venus, and Mars From: Svedhem, H., Titov, D.V., Taylor, F.W., Witasse, O. (2007). Venus as a more earth-like planet. Nature, 450, 29 November 2007.

Venus in Particular… From: Svedhem, H., Titov, D.V., Taylor, F.W., Witasse, O. (2007). Venus as a more earth-like planet. Nature, 450, 29 November 2007.

What if Venus, Earth, and Mars were different sizes? A smaller Venus is cooler, but not enough to be habitable. Nor is a larger Mars habitable. Earth is habitable at all three sizes. As with smaller amounts of real estate, what matters most is location, location, location. From: Levenson, B.P. (2011). Planet temperatures with surface cooling parameterized. Advances in Space Research, 47,

California Science Content Standards Addressed: High School Earth Science Standard 4. Energy enters the Earth system primarily as solar radiation and eventually escapes as heat. As a basis for understanding this concept: a. Students know the relative amount of incoming solar energy compared with Earth’s internal energy and the energy used by society. b. Students know the fate of incoming solar radiation in terms of reflection, absorption, and photosynthesis. c. Students know the different atmospheric gases that absorb the Earth’s thermal radiation and the mechanism and significance of the greenhouse effect. d.* Students know the differing greenhouse conditions on Earth, Mars, and Venus; the origins of those conditions; and the climatic consequences of each.

Thank You Contact information: Rich Ingrid All files (instructor notes, handouts, PowerPoints, videos) used in this presentation may be downloaded from: