ESCI 340 – Physical Meteorology

Answers to Selected Exercises for Cloud Physics Lesson 1

2.  Assume a population of cloud droplets follows the gamma distribution with a = 4.53´10 ²⁴ m^-6 and b = 2.35´10 ⁵ m^-1.

a.  What is the number density of the droplets (in cm^-3)?

  Answer:  698 cm^-3

b.  What is the liquid water content of the cloud (in g/m³)?

  Answer:  1.69 g/m³

c.  What is the surface area density of the drops  (in cm²/m³) (i.e., what is the total surface area of all the drops contained in a cubic meter of air?)

Answer:  4770 cm²/m³

d.  What is the mean drop diameter (in m m)?

Answer:  12.8 m m

e.  What is the mean distance between drops (in mm). 

Answer:  0.624 mm