Catalyst 4/10 What types of areas of Earth have - a high albedo? - a low albedo? (think urban, farmland, desert, etc.) Optional Slides: This is to prep students for next slide. Think of different types of areas on land.

Optional Slide: The colors in this image emphasize the albedo over the Earth’s land surfaces, ranging from 0.0 to 0.4. Areas colored red show the brightest, most reflective regions; yellows and greens are intermediate values; and blues and violets show relatively dark surfaces. White indicates where no data were available, and no albedo data are provided over the oceans. Remind student of what they learned about the distribution of sunlight with the Sun-Earth model. Sunlight does not reach everywhere equally. This image was produced using data composited over a 16-day period, from April 7-22, 2002. A new sensor aboard NASA’s Terra satellite is now collecting the most detailed and accurate measurements ever made of how much sunlight the Earth’s surface reflects back up into the atmosphere. By quantifying precisely our planet’s reflectivity, or albedo, the Moderate Resolution Imaging Spectroradiometer (MODIS) is helping scientists better understand and predict how various surface features influence both short-term weather patterns as well as longer-term climate trends. A low albedo mean that lots of energy is absorbed and only some is reflected. A high albedo like snow and ice means little absorption and lots of reflection. The most northern and southern areas are shown in white which means no data were available. Ask student - What would you predict for Antarctica? What would you predict about the temperature from this data? Does this give us the whole picture of climate? What about weather? What might cause a change in albedo in one location? Earth’s albedo Collected by NASA satellite and averaged. Does not include the ocean and no data for white areas.

Earth’s Energy Budget

Variables in the Energy Budget Where on Earth Pole vs. Equator Reflection (albedo) Material type Clouds Atmosphere Absorption and Re-radiation Variable can be used as a noun and an adjective. This is a list of variables (noun form) which are factors that vary. Variables may or may not impact the system. These variables impact the flow of energy through the Earth system.

Output= ? Input = Sunlight (short wave) Earth intercepts sunlight Sun emits radiation Review yesterday’s budget. This is the model that was developed on the first day of this lesson. 30% is reflected

Follow the Energy This figure follows the energy from the sun to the earth. It is helpful to start with the thickest yellow line on the left and follow the energy in the yellow lines. Focus on the left side of the image. The right side is today’s discussion.

Energy Moves in Three Ways Conduction • Convection • Radiation Conduction – Conduction is the process of handing on energy from one thing to the next. Example: A piece of metal that is hot at one end and cold at the other Convection – Convection is the process by which heat is transmitted in liquids and gases by the actual movement of the heated particles. Example: Heating a liquid in a container Radiation – Radiation is the process by which heat energy is transmitted from one place to another. Example: The sun Image from http://blogs.saschina.org/sophie01pd2016/2009/10/24/science/

Radiation seen in Infrared Images In this image, student can see the temperature of this animal. The temperature is detected as infrared waves of radiation. Image from http://en.wikipedia.org/wiki/Image:Infrared_dog.jpg

Radiation When energy is absorbed by an object (rock, water, building), the temperature of the object increases. All objects emit radiation. The amount and wavelength range is dependent on the temperature of the object. As the temperature increases (hotter), the wavelengths emitted by the object decreases (becomes shorter wavelengths).

Wavelengths of Energy Emitted by the Sun and Earth The Sun’s surface temperature is 5,500° C, and its peak radiation is in visible wavelengths of light. Earth’s effective temperature—the temperature it appears when viewed from space—is -20° C, and it radiates energy that peaks in thermal infrared wavelengths. (Illustration adapted from Robert Rohde.) http://earthobservatory.nasa.gov/Features/EnergyBalance/page2.php SHORT LONG

Incoming radiation is short wave and the outgoing radiation is long wave Emphasize that the incoming radiation is short wave and the outgoing radiation is long wave. This is important because in the next lesson we will discussion something that interacts with the long wave radiation but not the short wave radiation

Output= absorbed and re-radiated (long wave) Input = Sunlight (short wave) Earth intercepts sunlight Sun emits radiation Review yesterday’s budget. This is the model that was developed on the first day of this lesson. 30% is reflected

Missing one more variable A small part of the atmosphere is made of heat-trapping gases. These gases absorb long wave radiation. They are called greenhouse gases. Not all gases are greenhouse gases. Students may or may not have heard of greenhouse gases.

What is the greenhouse effect? The greenhouse is created by part of the atmosphere. The atmosphere is made up of gases including water vapor, some of which we see as clouds. Not all gases are greenhouse gases. Only those that absorb the long-wave radiation are called greenhouse gases. Most students have probably heard of carbon dioxide, but don’t know much about it. In the next lesson, the focus will be about these special gases. Students might also have experienced this feeling when they get into a car on a hot day. It feels much warmer inside the car because of the trapped air. So, it is different than the greenhouse effect but a connection to their experience. Students might be able come up with other examples as well. Air in the car is trapped and can’t get out. On Earth, there is no physical boundary, so it is the gases that actually work to hold the heat. After these three slides students should be able to fill out the graphic organizer comparing and contrasting a greenhouse with the “greenhouse effect”

Output= absorbed and re-radiated, (long wave) heat trapped by greenhouse gases Input = Sunlight (short wave) Earth intercepts sunlight Sun emits radiation Review yesterday’s budget. This is the model that was developed on the first day of this lesson. 30% is reflected

Composition of the Earth’s Atmosphere Nitrogen N2 = 78 % Oxygen O2 = 21 % Argon Ar = 0.9 % Other = <0.1% Carbon Dioxide CO2 Methane CH4 Nitrous Oxide NO2 Ozone O3 Hydrogen DAY 1- RESONANCE MODELS Most of our atmosphere is nitrogen and oxygen, neither of which is a greenhouse gas. Compare this to the Goldilocks effect. The greenhouse gases in our atmosphere are less than 0.1% of the total amount of gas in the atmosphere. Yet they are what make our planet inhabitable. Without the small amount of greenhouse gases, the average temperature on the planet would be 0 degrees F There is a major misconception that the hole in the ozone layer is the primary reason for climate change. It is correct to say that the ozone hole has a small effect on climate change, but is not the main cause.  The other connection between these issues is that Chlorofluorocarbons (CFCs) and their non-ozone-destroying replacements are very potent greenhouse gases, which also contribute to climate change. Students may or may not bring up these ideas in their discussion.

Greenhouse Gases Carbon Dioxide Water Methane Nitrous Oxide Ozone RESONANCE MODELS- Show the tennis ball models of the gases While this slide is up, students will complete the task card to use the models and discuss the following questions. Depending on your students it would also be possible to do this entirely as a demonstration. Is there a frequency at which it is much easier to keep the model vibrating? At this frequency your model molecule better absorbs and retains your energy output. If there is such a frequency, determine what it is in vibrations per second by counting the number of vibrations in a 5-second interval and dividing by 5. Do at least three trials, letting different member of your group experiment and obtain the range of frequencies at which the maximum energy is absorbed. Repeat this procedure for all three models. 1. How do the resonant frequencies of the 3 models compare? 2. What hypothesis can you formulate to explain your observations? 3. Physicists tell us that the behavior of the models built from the tennis balls is a good analogy of the behavior of real molecules of carbon dioxide, methane, and nitrogen. From the observations of your models, can you explain why some gases in the atmosphere absorb infrared radiation and others do not? 4. Why do you think greenhouse gases absorb infrared radiation and do not absorb visible light?

The “Goldilocks” Principle Why is the greenhouse effect so important? This slide compares the temperatures on three planets with and without greenhouse gases. All of them do experience warmer temperatures with the greenhouse gases. The next slide is specifically the Earth and temperatures are reported in Fahrenheit (which might be more familiar to the students). Recent calculations by NASA actually put the temperature change due to GHGs at only 20 degrees, not the 33 degrees in the chart. This is mostly because of using a different albedo number to consider the effects of solar and longwave radiation on the planetary albedo. The changed number is (-18 to -5) and is called the “atmosphere effect” of greenhouse gases, as opposed to the “enhanced atmospheric test” associated by the increase in greenhouse gases due to human activities. Mars is too cold, Venus is too hot, and Earth is just right!

What if Earth did not have greenhouse gases? Main Greenhouse Gases CO2 and H2O Estimated temperature without greenhouse gases -5 °C (23 °F) Actual average temperature 15 °C (59 °F) Temperature change because of greenhouse gases 20 °C (36 °F) This is an example of why we want to have greenhouse gases. They make our planet inhabitable and bring the temperature up to a level humans can live in. It does not mean that the temperature everywhere on everyday is equal to 59 degrees, but just that there is a dramatic change because of the GHG. We know this because we can look at other planets (Mars and Venus usually) and compare their temperatures and atmospheres to ours.

Use this slide to relate back to and debrief the lab Use this slide to relate back to and debrief the lab. What are the comparisons between the greenhouse gas lab and this picture? Ask students for similarities and differences. There is space on their lab notes to write their comments. Earth’s greenhouse effect Some gases preferentially absorb certain wavelengths of radiation and are transparent to others. This is because of resonance. As we just saw with the amount of shaking in the gas models, they shake more or less depending on how much energy you put into them. The long wave radiation is the resonance wavelength of the greenhouse gases.

This is a picture of the numbers that give us the greenhouse effect This is a picture of the numbers that give us the greenhouse effect. This gives a more energy budget example of the previous picture. Explain that most of the solar irradiation reaching the lower atmosphere is visible light, but there are other wavelengths present as well. Some of the gases (including water vapor) in the atmosphere reflect incoming solar irradiation, some allow it to pass through to the Earth’s surface (where it is absorbed), and some absorb it. The radiation (mostly visible light) that is absorbed in the atmosphere or by the Earth’s surface is re-emitted as long wave infrared energy (heat). When long wave radiation interacts with the atmosphere, different molecules will reflect, absorb, or allow it to pass through to space. Point out that the passing of long wave radiation from the Earth’s surface to the atmosphere, back to the Earth’s surface and so on is the fate of large quantities of solar irradiation and a major positive forcing. So the atmospheric gases that allow visible light to pass through but then absorb and re-emit long wave radiation are of huge interest to us (they can be thought of as like the car’s windshield), we call these “greenhouse gases” because they create a “greenhouse effect” in the Earth’s atmosphere.

More Complete (and complex!) Energy Balance Model OPTIONAL: This is a much more complicated diagram. The idea is to follow the energy on the left which is the incoming solar radiation and then follow the energy (outgoing radiation) out on the right. The idea is to show that there are many more things going on but that they have the general idea. DO NOT SPEND TOO MUCH TIME HERE!!!! Incoming Solar Radiation = Outgoing Radiation