Prof. Dr. J.P. Burrows Institute of Environmental Physics

Atmospheric Physics, WS 2007/2008 Exercise 0

0.1 The Earth’s

Describe the composition of the atmosphere. 1. What are the bulk constituents of the atmosphere? 2. Name the five to ten minor constituents of the atmosphere. 3. Identify the major sources and sinks of the in (1) and (2). 4. Specify if the gases in (1) and (2) are greenhouse gases or not. 5. Give examples of permanent and variable atmospheric gases.

0.2 Vertical thermal structure and vertical mixing of the atmosphere

Describe the vertical thermal structure of the atmosphere. 1. Sketch and label properly the temperature and mixing structure of the atmosphere. Kindly consider sketching the atmosphere from sea-level to 150 km . Explain all properties and features of each temperature and mixing zones. 2. Explain what makes the Earth’s stratosphere unique. 3. Which part of the atmosphere is the temperature extremely variable? Explain what causes the extreme temperature variability in this part of the atmosphere. 4. What is the temperature required to obtain the probability that 50 % of oxygen - cules would escape from the Earth’s atmosphere? Use the Maxwell-Boltzmann velocity distribution function. 5. Enumerate and explain the factors that determine whether a planet will hold an atmos- phere.

0.3 Barometric formula

1. State the exponential dependence with height z of the following. State all assumptions used. Explain all occurring variables. (a) (b) (c) thickness between iso- baric layers (Hint: the ) 2. Using the equations (a) and (b) derive the expressions for p(z) and ρ(z) for an atmospheric − dT ≡ layer in which the , dz = constant Γ. 3. Define the term . What is its value for the Earth’s atmosphere? 4. What about for the individual gaseous constituents of the atmosphere? What determines the scale height of each ? Under what conditions does the scale height of each gas is valid? 5. Determine the scale heights of the following gases (a) molecular and atomic hydrogen (b) molecular and atomic oxygen (c) molecular and atomic nitrogen.

0.4 Adiabatic lapse rate, potential temperature, and stability

1. Define adiabatic lapse rate. Explain the difference between (a) dry, (b) moist, (c) unsa- turated, (d) saturated, (e) supersaturated and (f) actual adiabatic lapse rates. 2. When will an air parcel change from cooling at the dry adiabatic lapse rate to the moist adiabatic lapse rate? 3. Define potential temperature? Why is potential temperature useful? 4. Define atmospheric stability. Explain what determines if a rising air parcel is stable, neutral, or unstable? Explain the difference between absolute and conditional stability or instability. Name the factors that influences the increase of stability or instability.

5. An air parcel at the surface is non-saturated and has a temperature of 303 K and a Tdew of 298 K. Assuming it moves adiabatically and the saturated adiabatic lapse rate Γsat = -8.5 deg C/1 km what will be the air temperature at 3000 m? What would be the temperature at 3000 m if the Γsat was -6.5 deg C/1000 m? (i.e. assuming the only thing that changed from the above problem is the Γsat).

Return date: Thursday, 10. Jan. 2008, 17:00, Post Box 100 Tutor: Joseph Pagaran, Room: S4300, Tel. No.: 0421-218-8265, email: [email protected] Additional info: http://www.iup.uni-bremen.de/~pagaran/AP0708.html