Homework for Chapter 2 - Energy: Warming the Earth and the Atmosphere

Questions 1 and 2 will be turned in for a grade. Questions 3-10 will be discussed by the discussion groups in class so please look them over before the discussion session. 

SHOW ALL WORK , CIRCLE THE CORRECT ANSWER, PLEASE BE NEAT AND STAPLE YOUR HOMEWORK!

ALSO, PLEASE USE A SPREADSHEET FOR ALL GRAPHS

Follow the Problem solving steps discussed in class

1.  Let's say that you have 1 kg of air.  Within that 1 kg of air, there are 50 grams of ice.  

a.  How much heat is required to sublimate the ice?

b.  Assuming that the heat required to sublimate the ice comes from the 1 kg of air, how much colder does the air become after all the ice has sublimated?

c.  Can you think of an example of how this process may be important in the atmosphere?

2.  Let's consider the wall in a dorm room that has a temperature of 20 degrees C.  Let's also assume that it is acting as a blackbody and that it is 3 meters tall and 5 meters wide.

a.  What is the total amount of radiation it is emitting?

b.  At what wavelength is it emitting most of its radiation?

c.  Can you see the radiation it is emitting?  Why or why not?

3     a. In a hurricane, if 100 grams of water vapor condense into water every second, how many calories of heat are released into the atmosphere in one day? How much additional heat per day would be released if the water then froze into ice particles?

        b. If the mass of a dry air parcel in a thunderstorm is 50 kg, how much cooler will the parcel be if 40 grams of ice sublimates into water vapor within the parcel?

4. Suppose your surface body temperature averages 90°F. How much radiant energy in W m^-2 would be emitted from your body? What is the total radiant energy emitted by your body in Watts? At what wavelength is this radiant energy emitted?

5. Explain why bridges often become icy before the rest of the road?

6. In the northern latitudes, the oceans are warmer in summer than they are in winter. In which season do the oceans lose heat most rapidly to the atmosphere by conduction? Explain.

7. How is heat transferred away from the surface of the moon? The moon has no atmosphere.

8. Why does the surface temperature often increase on a clear, calm night as a low cloud moves overhead?

9. Which would have the greatest effect on the earth's greenhouse effect: Removing all of the CO₂ from the atmosphere or removing all of the water vapor? Explain.

10. Explain why an increase in cloud cover surrounding the earth would increase the earth's albedo, yet not neccessarily lead to al lower earth surface temperature.

Extra Credit:  Consider a snow-covered surface.  Assume that the amount of solar radiation that reaches the top of the atmosphere is 1367 Wm^-2.  Given that 50% of this solar radiation is either absorbed in the atmosphere or reflected by clouds before reaching the the snow covered surface, how much of the original shortwave radiation is absorbed by the snow?   

last updated: 08/10/06