1. Conservation of Moisture
The Moisture Equation

2. 1st Law of Thermodynamics (Conservation of Energy)
Equation of State
1st Law of Thermodynamics (Conservation of Energy)
Moisture Equation (Conservation of Moisture)
Continuity Equation (Conservation of Mass)
Equations of Motion (Conservation of Momentum)
Coming to an ATMS 251 lab near you on March 22

3. Hydrologic Cycle – What can happen to moisture?

4. Moisture Equation
Mathematical representation of what can happen to water in a column of the atmosphere
Evapotranspiration
from ground
Change of moisture
storage in the
column
Precipitation
Moisture Inflow from
atmosphere
Moisture Outflow
from column

5. Precipitable Water
The vertical integral of the specific humidity for a column of atmosphere
Represents the upper limit to the total precipitation that may fall
Units: m (mm)

6. Average Specific Humidity
for the layer
Pressure Interval
Sum up the
number of levels
This will yield the precipitable water in units of kg/m2. To get PW in
units of meters, divide by the density of water (ρw=1000 kg/m3)

8. Moisture Advection
Of course, moisture can be transported horizontally and vertically in the atmosphere
Moisture Advection