ESS124
Prof. Jin-Yi Yu
Vapor Pressure
• The air’s content of moisture can be measured by the pressure exerted by the water vapor in the air.
•The total pressure inside an air parcel is equal to the sum of pressures of the individual gases.
•In the left figure, the total pressure of the air parcel is equal to sum of vapor pressure plus the pressures exerted by Nitrogen and Oxygen.
•High vapor pressure indicates large numbers of water vapor molecules.
•Unit of vapor pressure is usually in mb.
D:\yu\maker\talk\uci\class\ESS55\image\vapor.pressure.gif
(from Meteorology Today)