Homework 7

 

This homework set is due on Wednesday, November 9 at the beginning of the lecture.

 

  1. Suppose we launched a radiosonde and determined that the temperatures aloft were as follows:
    At 5 km, temperature was 2 degrees C
    At 4 km, temperature was 10 degrees C
    At 3 km, temperature was 17 degrees C
    At 2 km, temperature was 21 degrees C
    At 1 km, temperature was 20 degrees C
    At 0 km, temperature was 15 degrees C
    For each of the following layers of the atmosphere, determine the environmental lapse rate (ELR), and then note whether the layer is "absolutely stable", "absolutely unstable", or "conditionally unstable".
     
    Layer ELR (degrees C / km) Stability
    4km-5km    
    3km-4km    
    2km-3km    
    1km-2km    
    0km-1km    

  2. In the previous problem, which layer or layers of the atmosphere would be described as being a "temperature inversion"? (Remember, a "layer" of the atmosphere has some thickness or depth, so the answer to this question cannot be "1 km", but rather something like "1 km - 3 km".)
     
  3. Suppose the temperature at the surface is 22 degrees C and the temperature 500m above the ground is 18.5 degrees C. What is the environmental lapse rate for this layer? Is this layer "absolutely stable", "absolutely unstable", or "conditionally unstable"?
     
  4. During what season and at what time of day is air-mass thunderstorm activity greatest? Why?
     
  5. Does entrainment intensify or weaken updrafts of thunderstorms? Why?
     
  6. Explain the differences between a "tornado watch" and a "tornado warning". (There are several differences--be sure to name at least three.)
     
  7. List at least 3 reasons why the number of people killed by tornadoes each year is decreasing?
     
  8. Explain the difference between the "adiabatic lapse rates" (i.e., the DALR and the MALR) and the "environmental lapse rate".