Part 3 - Energy Budget and Habitability (CIP3) Physics Instructions and Solution

Running head: EARTH’S ENERGY BUDGET

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Instructions Hide Part 3: Energy Budget and Habitability (CIP3) Activity Description 1. Go to: i. HYPERLINK "http://science-edu.larc.nasa.gov/energy_budget/' target="_blank">http://scienceedu.larc.nasa.gov/energy_budget/" http://science-edu.larc.nasa.gov/energy_budget/ and review.

Focus on the Earths Energy Budget diagram. ii. Please conduct informational research on Habitable Zones. You can also use: HYPERLINK "http://astro.unl.edu/naap/habitablezones/animations/stellarHabitableZone.html' target="_blank">http://astro.unl.edu/naap/habitablezones/animations/stellarHabitableZone.html" http://astro.unl.edu/naap/habitablezones/animations/stellarHabitableZone.html. From this simulator, you can go back and read some of the Main Content under Habitable Zones.

Regardless, do some research on Habitable Zones.

2. Refer to the Earths Energy Budget diagram above and describe your understanding of it.

Follow the numbers used and describe how they add up or dont add up. Be thorough and specific. Use the numbers in your response.

3. In referencing the Earths Energy Budget diagram, someone might state, The heat exchanges are in balance: the heat gained by the Earth through solar radiation equals the heat lost through thermal radiation. What is meant by this statement? What NSCI100 concepts are being used here? Explain.

4. Now make connections among the Earths Energy Budget diagram, the Habitable Zone information and the Vital Signs of Planet Earth by discussing what you think the impact on planet Earth would be for each of these three conditions if each condition was sustained for a significant amount of time : i. The heat gained by the Earth through solar radiation equals the heat lost through thermal radiation. ii. The heat gained by the Earth through solar radiation is less than the heat lost through thermal radiation. iii. The heat gained by the Earth through solar radiation is more than the heat lost through thermal radiation.

In addressing this culminating question, you should at least: a. Conduct informational research on the topic. Summarize the results of this literature search and include references.

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b. Use scientific terms correctly. c. Describe how each of Earths five main vital signs would change or not change and explain.

Use diagrams, extend the timeframes and add in what you think the graphs would look like. d. Suggest why each condition might exist. What factors influence these conditions? How would these factors change to result in each of the conditions? e. Back up your statements with references when possible. Some statements you make may be a result of connections among concepts that you have made on your own and other statements may be based upon a reliable resource that you have found through a literature search. Both are valid to use at this stage in the project. Be clear about which are which. f. Be thorough. You are to use this last activity (Part 3) to try to demonstrate your maximum understanding, rather than just trying to meet minimum requirements.

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Earth’s Energy Budget Name Institutional Affiliation

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Earth’s climate is primarily determined by Earth’s energy budget. The Earth’s energy budget essentially describes the various kinds of energy and amount that enter and exit the Earth system. The energy constitutes of the radiative components measurable by CERES (Clouds and the Earth’s Radiant Energy System) such as heat and light. Other energy components that transport energy or heat from the surface of Earth include evaporation, convection, and conduction (Kiehl, & Trenberth, 1997). Typically, on average and over the long term, the atmosphere achieves balance. The Earth’s energy budget provides an account of how much energy from the Sun enters the Earth system, how much of it is lost elsewhere in space and further provides an account of the energy remainder stored on the planet and its atmosphere (Farmer, & Cook, 2013).

Understanding of the Earth’s energy budget diagram The average amount of energy from the sun that falls on one square meter of surface outside the atmosphere of Earth is about 340.4 watts. This may also be referred to as the incoming solar radiation. With these 340.4 watts entering Earth, 77.0 watts are scattered or reflected back up by clouds and the atmosphere. 22.9 more watts from the radiation are reflected back by the surface of the earth. This makes the total solar radiation reflected to be 99.9 watts. Further, the atmosphere absorbs 77.1 watts of the solar radiation, leaving 163.3 watts to be absorbed by the earth’s surface. In the mere process of absorption, the radiation from the sun is converted into heat energy (Farmer, & Cook, 2013). Some of this heat energy is then emitted away from the surface of the earth as longer radiation infrared wavelength. Of the 163.3 watts absorbed by the earth surface, 86.4 watts are used to evaporate water as in evapotranspiration. In addition, 18.4 watts from the reminder energy absorbed by surface are used to complete the processes of convection and conduction thus causing loss of heat on the surface. Total energy emitted by the earth’s surface stands at 398.2 watts while that emitted by

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the \atmosphere is 169.9 watts and that emitted by clouds is 29.9 watts. The infrared radiation that leaves earth totals to 239.9 watts.

Balance of heat exchanges The heat gained by the Earth through radiation from the sun equals the heat lost through thermal radiation. This statements mean that the amount of energy that originates from the sun and directed to Earth is the same as the amount of energy that leaves the earth’s surface due to reflection and emission of infrared radiation. One NSCI100 concept used in the above explanation is the first law of thermodynamics or the law of conservation of energy. This law states that the total energy of a system that is isolated is constant and this energy cannot be created or destroyed but can be transformed into a number of forms (Stephens et al., 2012).

The physical law professes that, in a system, the total energy remains the same. The same applies in the case of the balance in heat exchanges between the surface of the earth, the atmosphere and solar radiation where the energy entering the earth’s surface equals that exiting it as explained above in the interpretation of the Earth’s energy budget diagram.

If the heat gained by planet earth through solar radiation was the same as the heat lost through thermal radiation for a significant amount of time, the impact on planet earth would be the same as the current situation of the planet, habitable and with just enough amount of pressure. This is because the energy produced and the energy absorbed is the same and there is no too much of either of the two aspects (Stephens et al., 2012). On the other hand, if the heat gained by the earth through solar radiation is, in one way or another, less than the heat lost through thermal radiation, the pressure would decrease forcing water (which remains in liquid form in balanced pressure) to sublimate into gas or water vapor (Maruyama et al., 2013). With the heat lost through thermal radiation being more than that gained from the sun, a deficit of heat on earth results rendering the planet cold. Coldness reduces the pressure under which Earth as a habitable zone survives. However, if the heat gained by earth through solar radiation is

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more than that lost through thermal radiation, the pressure would be higher than when one amount of energy equals the other (Maruyama et al., 2013). This is because the heat that remains on earth after thermal radiation is more than that which leaves the surface. This would render earth hotter than usual thus offsetting the processes on the surface of the earth as a habitable zone.

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Farmer, G. T., & Cook, J. (2013). Earth’s Energy Budget. In Climate Change Science: A Modern Synthesis (pp. 81-95). Springer Netherlands.

Kiehl, J. T., & Trenberth, K. E. (1997). Earth's annual global mean energy budget. Bulletin of the American Meteorological Society, 78(2), 197-208.

Maruyama, Ikoma, M., Genda, H., Hirose, K., Yokoyama, T., & Santosh, M. (2013). The naked planet Earth: most essential pre-requisite for the origin and evolution of life.

Geoscience Frontiers, 4(2), 141-165.

Stephens, G. L., Li, J., Wild, M., Clayson, C. A., Loeb, N., Kato, S., ... & Andrews, T. (2012). An update on Earth's energy balance in light of the latest global observations.

Nature Geoscience, 5(10), 691-696.