Atmospheric Structure and Moisture


Terms to Learn are in BOLD in the outline below.


Topic Outline:


  1. Composition – gases present
  2. Particulates

Vertical structure of atmosphere

  1. Five principal thermal layers
  • Troposphere (tropopause)
  • Stratosphere (stratopause)
  • Mesosphere (mesopause)
  • Thermosphere

Thermodynamics of Water

  1. Changes of state
    1. Calorie
    2. Temperature versus Heat
    3. Transitions of state: ** In order to achieve transitions of state, water must overcome both Van der Waals forces and hydrogen bonds.
  • melting (solid to liquid) = freezing (liquid to solid)
  • vaporization (liquid to gas) = condensation (gas to liquid)
  1. latent heat
    1. melting (fusion)
    2. vaporization (condensation)
    3. evaporation


  1. Mixing Ratio / Specific humidity
  2. Relative humidity
  • Dew point

Adiabatic processes

  1. Dry adiabatic lapse rate
  2. Lifting condensation level
  3. Saturated (wet) adiabatic lapse rate

Rising air – types of lifting:

  1. Convective
  2. Orographic
  3. Frontal
  4. Convergent

When you are finished with this topic, you should be able to answer the following questions

  1. What two gases are the most abundant in the atmosphere?
  2. What is the vertical structure of the atmosphere and what are the primary characteristics of each layer?
  3. What is the difference between temperature and heat?
  4. What is latent heat?
  5. How do the latent heats of melting, vaporization, and evaporation differ from each other and why?
  6. What is the difference between specific and relative humidity?
  7. What is the difference between the dry and wet adiabatic lapse rate and why?
  8. What is the lifting condensation level?
  9. Describe the different types of atmospheric lifting.