Meteo 465/565 The Middle Atmosphere

Problem Set # 1

assigned: 22 January 2003

due:          3 February 2003

1. Derive an expression for the total number of molecules in the atmosphere and determine the number. What fraction of the total molecules is in the stratosphere? If the CO₂ mixing ratio (by volume) is ~370 ppmv, what is the total mass of carbon in the atmosphere that is in the form of CO₂?

2. Assume that, all the sudden, the eddy activity of Earth's atmosphere ceases and all transport is controlled by molecular diffusion. 

a. What will be the final distribution of gases such as nitrogen, oxygen, argon, and carbon dioxide, assuming no sources or sinks of these gases?

b. What are the ratios of the final mixing ratio to the initial mixing ratio for these gases at the surface?

c. What are the ratios of the final mixing ratio to the initial mixing ratio for these gases at 30 km?

d. Estimate the characteristic time for the atmosphere to evolve from its current state, where all gases are equally mixed, to a state dominated by molecular diffusion?

3. Are the following reactions exothermic or endothermic?

a. O + N₂O ® 2 NO

b. O(¹D) + N₂O ® 2 NO

c. O₃ + H₂O ® 2 OH + O₂

d. Cl + CH₄ ® H + CH₃Cl

e. OH + HCl ® H₂O + Cl

4. Find the wavelength of light required to cause the following reactions:

a. O₂ + hn ® 2 O

b. CCl₃F + hn ® CCl₂F + Cl

c. CF₄ + hn ® CF₃ + F

d. O₃ + hn ® O(¹D) + O₂

5. Using the figures from the U.S. Standard Atmosphere that are in the syllabus, find the kinetic energy in a m³ of air at 0, 50, and 500 km. How do they compare?

6. Without doing any more reading, briefly state your understanding of the causes of the Antarctic Ozone Hole? How much uncertainty do you feel there is in the current understanding of the causes?