4.4. Mean Mixing Height and Atmospheric Dispersion

Try these first

1. 1.

   What happens to the air temperature as one rises in the atmosphere?

   Hint

   Think about how temperature feels as you climb a mountain.

2. 2.

   Define temperature inversion in one sentence.

   Hint

   Consider what happens during calm, clear nights.

3. 3.

   What is the dry adiabatic lapse rate?

   • 5 °C/km
   • 9.8 °C/km
   • 10.5 °C/km

   Hint

   Recall the standard rate for rising dry air.

4. 4.

   True or False: Temperature inversions improve air quality.

   • True
   • False

   Hint

   Think about what happens during calm nights.

5. 5.

   You have a stack emitting pollutants at 150 °C. If the environmental lapse rate is 6 °C/km and the dry adiabatic lapse rate remains 9.8 °C/km, find the height at which the pollutant will stabilize.

   Hint

   Establish the point where cooling rates equal the surrounding rate.

6. 6.

   Analyze a case where during winter a city experiences a temperature inversion. How would this affect air pollutants concentration compared to in the summer?

   Hint

   Consider the factors that influence air quality negatively in colder conditions.