SPU25_Sp18_HW1_KEY.docx - SPU 25 Energy and Climate Vision for the Future Spring 2018 Homework Set#1 Climate Basics DUE Monday 2\/12(1:00 pm in lecture

SPU25_Sp18_HW1_KEY.docx - SPU 25 Energy and Climate Vision...

This preview shows page 1 - 3 out of 9 pages.

SPU 25 Energy and Climate: Vision for the Future, Spring 2018 Homework Set #1 Climate Basics, DUE Monday 2/12 (1:00 pm in lecture) Name: _____________________________________ Section: __________ TF: _____________________ Score: ______/_______ Collaborators: _________________________________________________________________________________________________ Earth’s climate is a complex reflection of the distribution and movement of energy around the planet. The primary source of Earth’s energy is radiation from the Sun. In this problem set, you will see how this energy is received, lost, and stored, and the role of greenhouse gases in altering the climate. You will also understand how the distribution of energy influences climate and get some practice with basic quantitative problems and unit conversions. ( 40 points total) You will only receive credit if you show all your work and write legibly. I. Earth’s Energy Balance Planet Earth (including the solid earth, oceans, and atmosphere) is best described as an isolated system: energy, but not mass, can pass from Earth to space and vice versa. In this type of system, the energy balance may be described by: Energy gained = Energy lost – change in storage. 1. Greenhouse gases in the atmosphere prevent the radiation of energy to space, so they impact which term in the above equation? (1 point) Energy lost 2. Changing surface and ocean temperatures reflect which term in the above equation? (1 point) Change in storage II. Energy from the Sun 3. True or False : Summer is warmer than winter because the Earth is closer to the Sun. (1 point) 4. Currently, the energy from the Sun arriving at Earth’s orbital position amounts to 1,379 W m -2 , measured perpendicular to the direction of the sunlight (see figure below). a. Given that the Earth is a circular target for this energy and has a radius of 6.38 x 10 3 km, calculate the total rate at which solar energy is intercepted by the Earth. Report your answer in Watts. Recall that the area of a circle is r π 2 . (2 points) 1 Figure 1. The shadow formed by an illuminated sphere has a circular shape with a radius R equal to the radius of the sphere.
Image of page 1
A = 1.28*10 14 m 2 I = 1.76*10 17 W We calculate the cross-sectional area of the earth the multiply by the rate at which the sun is radiating energy to earth. (1 pt) Cross-sectional area of earth = r π 2 = π * (6.38 * 10 3 * 10 3 m) 2 = 1.27877 * 10 14 m 2 (1 pt) Solar energy intercepted = Cross-sectional area * rate at which the sun is radiating energy to earth = 1.27877 * 10 14 m 2 * 1379 W/m 2 = 1.76342 * 10 17 W The total rate at which solar energy is intercepted by earth is 1.76 * 10 17 W. b. Assuming that the energy from the Sun is eventually distributed equally over the entire surface area of the Earth, use your answer from part (a) to calculate the current average rate of incoming solar radiation. Express your answer in Watts per meter squared. Recall that the surface area of a sphere is 4 r π 2 . (2 points) I 0 = 1379 W.m -2 Divide by 4 to get I S = 344.8 W.m -2 We take the answer from part a and divide it by the surface area of earth (a sphere) (1 pt) Surface area of earth = 4 r π 2 = 4 π (6.38 * 10 3 * 10 3 m) 2 = 5.11507 * 10 14 m 2
Image of page 2
Image of page 3

You've reached the end of your free preview.

Want to read all 9 pages?

  • Fall '10
  • BOB
  • Energy, Greenhouse gas

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern

Stuck? We have tutors online 24/7 who can help you get unstuck.
A+ icon
Ask Expert Tutors You can ask You can ask You can ask (will expire )
Answers in as fast as 15 minutes