Lecture 6: Atmospheric Moisture
Humidity is the amount of water vapour in the air.
• Warm air holds much more moisture than cold air.
• The importance for the amount of moisture in the air is to see how energy is being
transferred through the water vapour in the air.
• Latent heat is being transferred from one area to another. (through absorption and
SH (specific humidity) is the actual quantity of water vapour in air.
• SH = mass of water vapour (g) / mass of total air (kg)
Saturation Specific Humidity is the maximum amount of H Ov (i.2. SH) that an air parcel can
contain at any given time.
• Dependent on temperature, exponential increase in saturation specific humidity as
Saturation is the change of phase once limit is reached.
• Density of gas cannot be increased above a certain level (saturation)
• Establishes equilibrium with the rates of evaporation and condensation when it reaches
Mixing a warm parcel (30 Celsius, 20g