Moisture & Atmospheric Stability

• hydrologic cycle
  • precipitation
  • evaporation/transpiration
  • infiltration
  • runoff
• water phases (states)
  • solid
  • liquid
  • gas
• latent/sensible heat
  • latent heat of vaporization
  • latent heat of fusion
• evaporation/condensation
• sublimation/deposition
• phase changes
• phase change calculations (.pdf file)
• water vapor content of air - absolute humidity and mixing ratio are similar. Both are expressed as the quantity of water vapor contained in a specific amount of air.

Under standard conditions (25^oC, 1 atm), the density of air is 1.168 kg/m³. Therefore,
1kg of air would have a volume of 0.8562m³. To summarize..... 1kg of air has a volume about 15% smaller than 1m³.

                                     mass of water vapor (grams)

• absolute humidity = ---------------------------------
•                                 volume of air (cubic meters)

•                                 mass of water vapor (grams)
• mixing ratio          = ---------------------------------
•                                 mass of dry air (kilograms)

• vapor pressure
• partial pressures & Dalton's Law: the total pressure exerted by a gaseous mixture is equal to the sum of the partial pressures of each individual component in a gas mixture.
• saturation - saturation mixing ratio graph
• relative humidity calculations with a decrease in temperature
• table of saturated mixing ratio

• relative humidity
  • home vs. desert
  • heat index
  • wind chill
• natural changes in relative humidity
• dew-point temperature
• humidity measurement
  • hygrometers
  • psychrometers
• adiabatic temp change example (ELR/DALR/WALR (.doc download)
• adiabatic cooling and condensation
  • dry adiabatic lapse rate (DALR) = 1.0^oC/100 meters / 5.5^oF/1000 feet
  • wet adiabatic lapse rate (WALR) = 0.5 - 0.9^oC/100 meters

DALR =   - 1.0^oC/100m
WALR =  +0.5^oC/100m
                -------------------
                 - 0.5^oC/100m

• processes that lift air
  • orographic lifting
    • rain shadows
  • frontal wedging
  • convergence (Florida satellite image)
  • convective lifting
• humidity calculations
• humidity/adiabatic lapse rate calculations (download)